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lm3s8938 microcontroller da t a sheet copyright ? 2007 luminary micro, inc. ds-lm3s8938-01 luminar y micro confidential-adv ance product informa tion
legal disclaimers and t rademark information informa tion in this document is provided in connection with luminar y micro products. no license, express or implied, by est oppel or other wise, t o any intellectual proper ty rights is granted by this document . except as provided in luminar y micro's terms and conditions of sale for such products, luminar y micro assumes no liability wha tsoever, and luminar y micro disclaims any express or implied w arranty , rela ting t o sale and/or use of luminar y micro's products including liability or w arranties rela ting t o fitness for a p ar ticular purpose, merchant ability , or infringement of any p a tent , copyright or other intellectual proper ty right . luminar y micro's products are not intended for use in medical, life sa ving, or life-sust aining applica tions. luminary micro may make changes to specifcations and product descriptions at any time, without notice. contact your local luminary micro sales offce or your distributor to obtain the latest specifcations before placing your product order . designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefned." luminary micro reserves these for future defnition and shall have no responsibility whatsoever for conficts or incompatibilities arising from future changes to them. copyright ? 2007 luminary micro, inc. all rights reserved. stellaris is a registered trademark and luminary micro and the luminary micro logo are trademarks of luminary micro, inc. or its subsidiaries in the united states and other countries. arm and thumb are registered trademarks and cortex is a trademark of arm limited. other names and brands may be claimed as the property of others. luminary micro, inc. 108 w ild basin, suite 350 austin, tx 78746 main: +1-512-279-8800 fax: +1-512-279-8879 http://www .luminarymicro.com june 14, 2007 2 luminary micro confidential-advance product information
t able of contents about this document .................................................................................................................... 20 audience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 about this manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 related documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 documentation conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 1 overview ............................................................................................................................. 22 1.1 product features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1.2 t arget applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.3 high-level block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.4 functional overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 1.4.1 arm cortex?-m3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1.4.2 motor control peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1.4.3 serial communications peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 1.4.4 system peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1.4.5 memory peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 1.4.6 additional features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 1.4.7 hardware details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 2 cortex-m3 core .................................................................................................................. 35 2.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.2.1 serial wire and jt ag debug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.2.2 embedded t race macrocell (etm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2.2.3 t race port interface unit (tpiu) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2.2.4 rom t able . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2.2.5 memory protection unit (mpu) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2.2.6 nested v ectored interrupt controller (nvic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 3 memory map ....................................................................................................................... 41 4 interrupts ............................................................................................................................ 43 5 jt ag .................................................................................................................................... 46 5.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 5.2.1 jt ag interface pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 5.2.2 jt ag t ap controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5.2.3 shift registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 5.2.4 operational considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 5.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 5.4 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 5.4.1 instruction register (ir) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 5.4.2 data registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 6 system control ................................................................................................................... 57 6.1 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 6.1.1 device identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 6.1.2 reset control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 6.1.3 power control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 3 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
6.1.4 clock control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 6.1.5 system control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 6.2 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 6.3 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 6.4 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 7 hibernation module .......................................................................................................... 113 7.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 7.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 7.2.1 register access t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 7.2.2 clock source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 7.2.3 battery management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 7.2.4 real-t ime clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 7.2.5 non-v olatile memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 7.2.6 power control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 7.2.7 interrupts and status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 7.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 7.3.1 initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 7.3.2 r tc match functionality (no hibernation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 7.3.3 r tc match/w ake-up from hibernation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 7.3.4 external w ake-up from hibernation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 7.3.5 r tc/external w ake-up from hibernation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 7.4 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 7.5 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 8 internal memory ............................................................................................................... 131 8.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 8.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 8.2.1 sram memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 8.2.2 flash memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 8.3 flash memory initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 8.3.1 flash programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 8.3.2 nonvolatile register programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 8.4 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 8.5 flash control of fset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 8.6 system control of fset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 9 gpio .................................................................................................................................. 155 9.1 function description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 9.1.1 data control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 9.1.2 interrupt control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 9.1.3 mode control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 9.1.4 commit control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 9.1.5 pad control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 9.1.6 identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 9.2 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 9.3 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 9.4 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 10 t imers ............................................................................................................................... 196 10.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 june 14, 2007 4 luminary micro confidential-advance product information t able of contents
10.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 10.2.1 gptm reset conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 10.2.2 32-bit t imer operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 10.2.3 16-bit t imer operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 10.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 10.3.1 32-bit one-shot/periodic t imer mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 10.3.2 32-bit real-t ime clock (r tc) mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 10.3.3 16-bit one-shot/periodic t imer mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 10.3.4 16-bit input edge count mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 10.3.5 16-bit input edge t iming mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 10.3.6 16-bit pwm mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 10.4 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 10.5 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 1 1 w atchdog t imer ............................................................................................................... 229 1 1.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 1 1.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 1 1.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 1 1.4 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 1 1.5 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 12 adc ................................................................................................................................... 252 12.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 12.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 12.2.1 sample sequencers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 12.2.2 module control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 12.2.3 hardware sample a veraging circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 12.2.4 analog-to-digital converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 12.2.5 t est modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 12.2.6 internal t emperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 12.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 12.3.1 module initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 12.3.2 sample sequencer configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 12.4 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 12.5 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 13 uart ................................................................................................................................. 285 13.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 13.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 13.2.1 t ransmit/receive logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 13.2.2 baud-rate generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 13.2.3 data t ransmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 13.2.4 serial ir (sir) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 13.2.5 fifo operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 13.2.6 interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 13.2.7 loopback operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 13.2.8 irda sir block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 13.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 13.4 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 13.5 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 5 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
14 ssi ..................................................................................................................................... 325 14.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 14.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 14.2.1 bit rate generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 14.2.2 fifo operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 14.2.3 interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 14.2.4 frame formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 14.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 14.4 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 14.5 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 15 inter-integrated circuit (i 2 c) interface ............................................................................ 359 15.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 15.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 15.2.1 i 2 c bus functional overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 15.2.2 a vailable speed modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 15.2.3 interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 15.2.4 loopback operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 15.2.5 command sequence flow charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 15.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 15.4 i 2 c register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371 15.5 i 2 c master . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372 15.6 i 2 c slave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 16 can ................................................................................................................................... 394 16.1 controller area network overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 16.2 controller area network features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 16.3 controller area network block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 16.4 controller area network functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396 16.4.1 initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396 16.4.2 operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 16.4.3 t ransmitting message objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 16.4.4 configuring a t ransmit message object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 16.4.5 updating a t ransmit message object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 16.4.6 accepting received message objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 16.4.7 receiving a data frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 16.4.8 receiving a remote frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 16.4.9 receive/t ransmit priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 16.4.10 configuring a receive message object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 16.4.1 1 handling of received message objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 16.4.12 handling of interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 16.4.13 bit t iming configuration error considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401 16.4.14 bit t ime and bit rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401 16.4.15 calculating the bit t iming parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403 16.5 controller area network register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 16.6 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407 17 ethernet ............................................................................................................................. 438 17.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 17.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 june 14, 2007 6 luminary micro confidential-advance product information t able of contents
17.2.1 internal mii operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 17.2.2 phy configuration/operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440 17.2.3 mac configuration/operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441 17.2.4 interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 443 17.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444 17.4 ethernet register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444 17.5 ethernet mac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446 17.6 mii management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 18 analog comparators ....................................................................................................... 482 18.1 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 18.2 functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 18.2.1 internal reference programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 18.3 initialization and configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 18.4 register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 18.5 register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 19 pin diagram ...................................................................................................................... 495 20 signal t ables .................................................................................................................... 496 21 operating characteristics ............................................................................................... 510 22 electrical characteristics ................................................................................................ 511 22.1 dc characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 22.1.1 maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 22.1.2 recommended dc operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 22.1.3 on-chip low drop-out (ldo) regulator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 22.1.4 power specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 22.1.5 flash memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 22.2 ac characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 22.2.1 load conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 22.2.2 clocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 22.2.3 t emperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 22.2.4 analog-to-digital converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 22.2.5 analog comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 22.2.6 i 2 c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 22.2.7 ethernet controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 22.2.8 hibernation module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 22.2.9 synchronous serial interface (ssi) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 22.2.10 jt ag and boundary scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 22.2.1 1 general-purpose i/o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 22.2.12 reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 23 package information ........................................................................................................ 525 24 ordering information ....................................................................................................... 527 24.1 ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 24.2 company information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 24.3 support information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 a serial flash loader .......................................................................................................... 528 a.1 serial flash loader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 a.2 interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 7 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
a.2.1 uar t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 a.2.2 ssi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 a.3 packet handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 a.3.1 packet format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 a.3.2 sending packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 a.3.3 receiving packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 a.4 commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530 a.4.1 command_ping (0x20) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530 a.4.2 command_get_st a tus (0x23) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530 a.4.3 command_download (0x21) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530 a.4.4 command_send_da t a (0x24) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531 a.4.5 command_run (0x22) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531 a.4.6 command_reset (0x25) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531 b register quick reference ............................................................................................... 533 june 14, 2007 8 luminary micro confidential-advance product information t able of contents
list of figures figure 1-1. stellaris? fury-class high-level block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 figure 2-1. cpu block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 figure 2-2. tpiu block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 figure 5-1. jt ag module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 figure 5-2. t est access port state machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 figure 5-3. idcode register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 figure 5-4. byp ass register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 figure 5-5. boundary scan register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 figure 6-1. external circuitry to extend reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 figure 7-1. hibernation module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 figure 8-1. flash block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 figure 9-1. gpioda t a w rite example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 figure 9-2. gpioda t a read example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 figure 10-1. gptm module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 figure 10-2. 16-bit input edge count mode example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 figure 10-3. 16-bit input edge t ime mode example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 figure 10-4. 16-bit pwm mode example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 figure 1 1-1. wdt module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 figure 12-1. adc module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 figure 12-2. internal t emperature sensor characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 figure 13-1. uar t module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 figure 13-2. uar t character frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 figure 13-3. irda data modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 figure 14-1. ssi module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 figure 14-2. ti synchronous serial frame format (single t ransfer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 figure 14-3. ti synchronous serial frame format (continuous t ransfer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 figure 14-4. freescale spi format (single t ransfer) with spo=0 and sph=0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 figure 14-5. freescale spi format (continuous t ransfer) with spo=0 and sph=0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 figure 14-6. freescale spi frame format with spo=0 and sph=1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 figure 14-7. freescale spi frame format (single t ransfer) with spo=1 and sph=0 . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 figure 14-8. freescale spi frame format (continuous t ransfer) with spo=1 and sph=0 . . . . . . . . . . . . . . . . . . . . 331 figure 14-9. freescale spi frame format with spo=1 and sph=1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 figure 14-10. microwire frame format (single frame) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 figure 14-1 1. microwire frame format (continuous t ransfer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 figure 14-12. microwire frame format, ssifss input setup and hold requirements . . . . . . . . . . . . . . . . . . . . . . . . 334 figure 15-1. i 2 c block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 figure 15-2. i 2 c bus configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 figure 15-3. st ar t and st op conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 figure 15-4. complete data t ransfer with a 7-bit address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 figure 15-5. r/s bit in first byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 figure 15-6. data v alidity during bit t ransfer on the i 2 c bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 figure 15-7. master single send . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 figure 15-8. master single receive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 figure 15-9. master burst send . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 figure 15-10. master burst receive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 figure 15-1 1. master burst receive after burst send . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 9 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
figure 15-12. master burst send after burst receive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 figure 15-13. slave command sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 figure 16-1. can module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 figure 16-2. can bit t ime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 figure 17-1. ethernet controller block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 figure 17-2. ethernet controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 figure 17-3. ethernet frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441 figure 18-1. analog comparator module block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 figure 18-2. structure of comparator unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 figure 18-3. comparator internal reference structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 figure 19-1. pin connection diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495 figure 22-1. load conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 figure 22-2. i 2 c t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 figure 22-3. external xtlp oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518 figure 22-4. hibernation module t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 figure 22-5. ssi t iming for ti frame format (frf=01), single t ransfer t iming measurement . . . . . . . . . . . . . . 520 figure 22-6. ssi t iming for microwire frame format (frf=10), single t ransfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520 figure 22-7. ssi t iming for spi frame format (frf=00), with sph=1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 figure 22-8. jt ag t est clock input t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 figure 22-9. jt ag t est access port (t ap) t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 figure 22-10. jt ag trst t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 figure 22-1 1. external reset t iming ( rst ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 figure 22-12. power-on reset t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524 figure 22-13. brown-out reset t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524 figure 22-14. software reset t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524 figure 22-15. w atchdog reset t iming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524 figure 23-1. 100-pin lqfp package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525 june 14, 2007 10 luminary micro confidential-advance product information t able of contents
list of t ables t able 1. documentation conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 t able 3-1. memory map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 t able 4-1. exception t ypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 t able 4-2. interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 t able 5-1. jt ag port pins reset state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 t able 5-2. jt ag instruction register commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 t able 6-1. system control register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 t able 6-2. v adj to vout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 t able 6-3. default crystal field v alues and pll programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 t able 7-1. hibernation module register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 t able 8-1. flash protection policy combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 t able 8-2. flash resident registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 t able 8-3. internal memory register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 t able 9-1. gpio pad configuration examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 t able 9-2. gpio interrupt configuration example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 t able 9-3. gpio register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 t able 10-1. 16-bit t imer with prescaler configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 t able 10-2. t imers register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 t able 1 1-1. w atchdog t imer register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 t able 12-1. samples and fifo depth of sequencers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 t able 12-2. adc register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 t able 13-1. uar t register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 t able 14-1. ssi register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 t able 15-1. examples of i 2 c master t imer period versus speed mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 t able 15-2. inter-integrated circuit (i 2 c) interface register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371 t able 15-3. w rite field decoding for i2cmcs[3:0] field (sheet 1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 t able 16-1. t ransmit message object bit settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 t able 16-2. receive message object bit settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 t able 16-3. can protocol ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 t able 16-4. can register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 t able 17-1. tx & rx fifo organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442 t able 17-2. ethernet register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445 t able 18-1. comparator 0 operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 t able 18-2. comparator 1 operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 t able 18-3. comparator 2 operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 t able 18-4. internal reference v oltage and acrefctl field v alues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 t able 18-5. analog comparators register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 t able 20-1. signals by pin number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 496 t able 20-2. signals by signal name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500 t able 20-3. signals by function, except for gpio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504 t able 20-4. gpio pins and alternate functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508 t able 21-1. t emperature characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510 t able 21-2. thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510 t able 22-1. maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 t able 22-2. recommended dc operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 t able 22-3. ldo regulator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 1 1 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
t able 22-4. flash memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 t able 22-5. phase locked loop (pll) characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 t able 22-6. clock characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 t able 22-7. crystal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 t able 22-8. t emperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 t able 22-9. adc characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 t able 22-10. analog comparator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 t able 22-1 1. analog comparator v oltage reference characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 t able 22-12. i 2 c characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 t able 22-13. 100base-tx t ransmitter characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 t able 22-14. 100base-tx t ransmitter characteristics (informative) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 t able 22-15. 100base-tx receiver characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 t able 22-16. 10base-t t ransmitter characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 t able 22-17. 10base-t t ransmitter characteristics (informative) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 t able 22-18. 10base-t receiver characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 t able 22-19. isolation t ransformers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 t able 22-20. ethernet reference crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518 t able 22-21. external xtlp oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518 t able 22-22. hibernation module characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 t able 22-23. ssi characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 t able 22-24. jt ag characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 t able 22-25. gpio characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 t able 22-26. reset characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 t able 24-1. part ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 june 14, 2007 12 luminary micro confidential-advance product information t able of contents
list of registers system control .............................................................................................................................. 57 register 1: device identification 0 (did0), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 register 2: brown-out reset control (pborctl), of fset 0x030 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 register 3: ldo power control (ldopctl), of fset 0x034 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 register 4: raw interrupt status (ris), of fset 0x050 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 register 5: interrupt mask control (imc), of fset 0x054 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 register 6: masked interrupt status and clear (misc), of fset 0x058 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 register 7: reset cause (resc), of fset 0x05c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 register 8: run-mode clock configuration (rcc), of fset 0x060 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 register 9: xt al to pll t ranslation (pllcfg), of fset 0x064 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 register 10: run-mode clock configuration 2 (rcc2), of fset 0x070 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 register 1 1: deep sleep clock configuration (dslpclkcfg), of fset 0x144 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 register 12: device identification 1 (did1), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 register 13: device capabilities 0 (dc0), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 register 14: device capabilities 1 (dc1), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 register 15: device capabilities 2 (dc2), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 register 16: device capabilities 3 (dc3), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 register 17: device capabilities 4 (dc4), of fset 0x01c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 register 18: run mode clock gating control register 0 (rcgc0), of fset 0x100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 register 19: sleep mode clock gating control register 0 (scgc0), of fset 0x1 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 register 20: deep sleep mode clock gating control register 0 (dcgc0), of fset 0x120 . . . . . . . . . . . . . . . . . . . . . . . . . 95 register 21: run mode clock gating control register 1 (rcgc1), of fset 0x104 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 register 22: sleep mode clock gating control register 1 (scgc1), of fset 0x1 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 register 23: deep sleep mode clock gating control register 1 (dcgc1), of fset 0x124 . . . . . . . . . . . . . . . . . . . . . . . 101 register 24: run mode clock gating control register 2 (rcgc2), of fset 0x108 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 register 25: sleep mode clock gating control register 2 (scgc2), of fset 0x1 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 register 26: deep sleep mode clock gating control register 2 (dcgc2), of fset 0x128 . . . . . . . . . . . . . . . . . . . . . . . 107 register 27: software reset control 0 (srcr0), of fset 0x040 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 register 28: software reset control 1 (srcr1), of fset 0x044 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 register 29: software reset control 2 (srcr2), of fset 0x048 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 hibernation module ..................................................................................................................... 113 register 1: hibernation r tc counter (hibr tcc), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 register 2: hibernation r tc match 0 (hibr tcm0), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 register 3: hibernation r tc match 1 (hibr tcm1), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 register 4: hibernation r tc load (hibr tcld), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 register 5: hibernation control (hibctl), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 register 6: hibernation interrupt mask (hibim), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 register 7: hibernation raw interrupt status (hibris), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 register 8: hibernation masked interrupt status (hibmis), of fset 0x01c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 register 9: hibernation interrupt clear (hibic), of fset 0x020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 register 10: hibernation r tc t rim (hibr tct), of fset 0x024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 register 1 1: hibernation data (hibda t a), of fset 0x030-0x12c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 internal memory ........................................................................................................................... 131 register 1: flash memory address (fma), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 register 2: flash memory data (fmd), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 13 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: flash memory control (fmc), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 register 4: flash controller raw interrupt status (fcris), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 register 5: flash controller interrupt mask (fcim), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 register 6: flash controller masked interrupt status and clear (fcmisc), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . 142 register 7: usec reload (usecrl), of fset 0x140 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 register 8: flash memory protection read enable 0 (fmpre0), of fset 0x130 and 0x200 . . . . . . . . . . . . . . . . . . . 144 register 9: flash memory protection program enable 0 (fmppe0), of fset 0x134 and 0x400 . . . . . . . . . . . . . . . 145 register 10: user debug (user_dbg), of fset 0x1d0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 register 1 1: user register 0 (user_reg0), of fset 0x1e0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 register 12: user register 1 (user_reg1), of fset 0x1e4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 register 13: flash memory protection read enable 1 (fmpre1), of fset 0x204 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 register 14: flash memory protection read enable 2 (fmpre2), of fset 0x208 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 register 15: flash memory protection read enable 3 (fmpre3), of fset 0x20c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 register 16: flash memory protection program enable 1 (fmppe1), of fset 0x404 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 register 17: flash memory protection program enable 2 (fmppe2), of fset 0x408 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 register 18: flash memory protection program enable 3 (fmppe3), of fset 0x40c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 gpio .............................................................................................................................................. 155 register 1: gpio data (gpioda t a), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 register 2: gpio direction (gpiodir), of fset 0x400 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 register 3: gpio interrupt sense (gpiois), of fset 0x404 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 register 4: gpio interrupt both edges (gpioibe), of fset 0x408 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 register 5: gpio interrupt event (gpioiev), of fset 0x40c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 register 6: gpio interrupt mask (gpioim), of fset 0x410 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 register 7: gpio raw interrupt status (gpioris), of fset 0x414 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 register 8: gpio masked interrupt status (gpiomis), of fset 0x418 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 register 9: gpio interrupt clear (gpioicr), of fset 0x41c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 register 10: gpio alternate function select (gpioafsel), of fset 0x420 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 register 1 1: gpio 2-ma drive select (gpiodr2r), of fset 0x500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 register 12: gpio 4-ma drive select (gpiodr4r), of fset 0x504 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 register 13: gpio 8-ma drive select (gpiodr8r), of fset 0x508 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 register 14: gpio open drain select (gpioodr), of fset 0x50c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 register 15: gpio pull-up select (gpiopur), of fset 0x510 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 register 16: gpio pull-down select (gpiopdr), of fset 0x514 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 register 17: gpio slew rate control select (gpioslr), of fset 0x518 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 register 18: gpio digital enable (gpioden), of fset 0x51c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 register 19: gpio lock (gpiolock), of fset 0x520 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 register 20: gpio commit (gpiocr), of fset 0x524 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 register 21: gpio peripheral identification 4 (gpioperiphid4), of fset 0xfd0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 register 22: gpio peripheral identification 5 (gpioperiphid5), of fset 0xfd4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 register 23: gpio peripheral identification 6 (gpioperiphid6), of fset 0xfd8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 register 24: gpio peripheral identification 7 (gpioperiphid7), of fset 0xfdc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 register 25: gpio peripheral identification 0 (gpioperiphid0), of fset 0xfe0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 register 26: gpio peripheral identification 1(gpioperiphid1), of fset 0xfe4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 register 27: gpio peripheral identification 2 (gpioperiphid2), of fset 0xfe8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 register 28: gpio peripheral identification 3 (gpioperiphid3), of fset 0xfec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 register 29: gpio primecell identification 0 (gpiopcellid0), of fset 0xff0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 register 30: gpio primecell identification 1 (gpiopcellid1), of fset 0xff4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 register 31: gpio primecell identification 2 (gpiopcellid2), of fset 0xff8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 june 14, 2007 14 luminary micro confidential-advance product information t able of contents
register 32: gpio primecell identification 3 (gpiopcellid3), of fset 0xffc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 t imers ........................................................................................................................................... 196 register 1: gptm configuration (gptmcfg), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 register 2: gptm t imera mode (gptmt amr), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 register 3: gptm t imerb mode (gptmtbmr), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 register 4: gptm control (gptmctl), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 register 5: gptm interrupt mask (gptmimr), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 register 6: gptm raw interrupt status (gptmris), of fset 0x01c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 register 7: gptm masked interrupt status (gptmmis), of fset 0x020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 register 8: gptm interrupt clear (gptmicr), of fset 0x024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 register 9: gptm t imera interval load (gptmt ailr), of fset 0x028 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 register 10: gptm t imerb interval load (gptmtbilr), of fset 0x02c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 register 1 1: gptm t imera match (gptmt ama tchr), of fset 0x030 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 register 12: gptm t imerb match (gptmtbma tchr), of fset 0x034 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 register 13: gptm t imera prescale (gptmt apr), of fset 0x038 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 register 14: gptm t imerb prescale (gptmtbpr), of fset 0x03c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 register 15: gptm t imera prescale match (gptmt apmr), of fset 0x040 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 register 16: gptm t imerb prescale match (gptmtbpmr), of fset 0x044 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 register 17: gptm t imera (gptmt ar), of fset 0x048 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 register 18: gptm t imerb (gptmtbr), of fset 0x04c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 w atchdog t imer ........................................................................................................................... 229 register 1: w atchdog load (wdtload), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 register 2: w atchdog v alue (wdtv alue), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 register 3: w atchdog control (wdtctl), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 register 4: w atchdog interrupt clear (wdticr), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 register 5: w atchdog raw interrupt status (wdtris), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 register 6: w atchdog masked interrupt status (wdtmis), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 register 7: w atchdog t est (wdttest), of fset 0x418 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 register 8: w atchdog lock (wdtlock), of fset 0xc00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 register 9: w atchdog peripheral identification 4 (wdtperiphid4), of fset 0xfd0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 register 10: w atchdog peripheral identification 5 (wdtperiphid5), of fset 0xfd4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 register 1 1: w atchdog peripheral identification 6 (wdtperiphid6), of fset 0xfd8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 register 12: w atchdog peripheral identification 7 (wdtperiphid7), of fset 0xfdc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 register 13: w atchdog peripheral identification 0 (wdtperiphid0), of fset 0xfe0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 register 14: w atchdog peripheral identification 1 (wdtperiphid1), of fset 0xfe4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 register 15: w atchdog peripheral identification 2 (wdtperiphid2), of fset 0xfe8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 register 16: w atchdog peripheral identification 3 (wdtperiphid3), of fset 0xfec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 register 17: w atchdog primecell identification 0 (wdtpcellid0), of fset 0xff0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 register 18: w atchdog primecell identification 1 (wdtpcellid1), of fset 0xff4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 register 19: w atchdog primecell identification 2 (wdtpcellid2), of fset 0xff8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 register 20: w atchdog primecell identification 3 (wdtpcellid3 ), of fset 0xffc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 adc ............................................................................................................................................... 252 register 1: adc active sample sequencer (adcactss), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 register 2: adc raw interrupt status (adcris), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 register 3: adc interrupt mask (adcim), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 register 4: adc interrupt status and clear (adcisc), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 register 5: adc overflow status (adcost a t), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 register 6: adc event multiplexer select (adcemux), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 15 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: adc underflow status (adcust a t), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 register 8: adc sample sequencer priority (adcsspri), of fset 0x020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 register 9: adc processor sample sequence initiate (adcpssi), of fset 0x028 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 register 10: adc sample a veraging control (adcsac), of fset 0x030 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268 register 1 1: adc sample sequence input multiplexer select 0 (adcssmux0), of fset 0x040 . . . . . . . . . . . . . . . 269 register 12: adc sample sequence control 0 (adcssctl0), of fset 0x044 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 register 13: adc sample sequence result fifo 0 (adcssfifo0), of fset 0x048 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 register 14: adc sample sequence result fifo 1 (adcssfifo1), of fset 0x068 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 register 15: adc sample sequence result fifo 2 (adcssfifo2), of fset 0x088 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 register 16: adc sample sequence fifo 0 status (adcssfst a t0), of fset 0x04c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 register 17: adc sample sequence fifo 1 status (adcssfst a t1), of fset 0x06c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 register 18: adc sample sequence fifo 2 status (adcssfst a t2), of fset 0x08c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 register 19: adc sample sequence input multiplexer select 1 (adcssmux1), of fset 0x060 . . . . . . . . . . . . . . . 275 register 20: adc sample sequence control 1 (adcssctl1), of fset 0x064 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 register 21: adc sample sequence input multiplexer select 2 (adcssmux2), of fset 0x080 . . . . . . . . . . . . . . . 277 register 22: adc sample sequence control 2 (adcssctl2), of fset 0x084 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 register 23: adc sample sequence input multiplexer select 3 (adcssmux3), of fset 0x0a0 . . . . . . . . . . . . . . . 279 register 24: adc sample sequence control 3 (adcssctl3), of fset 0x0a4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 register 25: adc sample sequence result fifo 3 (adcssfifo3), of fset 0x0a8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 register 26: adc sample sequence fifo 3 status (adcssfst a t3), of fset 0x0ac . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282 register 27: adc t est mode loopback (adctmlb), of fset 0x100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 uart ............................................................................................................................................. 285 register 1: uar t data (uar tdr), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 register 2: uar t receive status/error clear (uar trsr/uar tecr), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 register 3: uar t flag (uar tfr), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 register 4: uar t irda low-power register (uar tilpr), of fset 0x020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 register 5: uar t integer baud-rate divisor (uar tibrd), of fset 0x024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 register 6: uar t fractional baud-rate divisor (uar tfbrd), of fset 0x028 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 register 7: uar t line control (uar tlcrh), of fset 0x02c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 register 8: uar t control (uar tctl), of fset 0x030 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 register 9: uar t interrupt fifo level select (uar tifls), of fset 0x034 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306 register 10: uar t interrupt mask (uar tim), of fset 0x038 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 register 1 1: uar t raw interrupt status (uar tris), of fset 0x03c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 register 12: uar t masked interrupt status (uar tmis), of fset 0x040 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 register 13: uar t interrupt clear (uar ticr), of fset 0x044 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 register 14: uar t peripheral identification 4 (uar tperiphid4), of fset 0xfd0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 register 15: uar t peripheral identification 5 (uar tperiphid5), of fset 0xfd4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 register 16: uar t peripheral identification 6 (uar tperiphid6), of fset 0xfd8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 register 17: uar t peripheral identification 7 (uar tperiphid7), of fset 0xfdc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 register 18: uar t peripheral identification 0 (uar tperiphid0), of fset 0xfe0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 register 19: uar t peripheral identification 1 (uar tperiphid1), of fset 0xfe4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 register 20: uar t peripheral identification 2 (uar tperiphid2), of fset 0xfe8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 register 21: uar t peripheral identification 3 (uar tperiphid3), of fset 0xfec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 register 22: uar t primecell identification 0 (uar tpcellid0), of fset 0xff0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 register 23: uar t primecell identification 1 (uar tpcellid1), of fset 0xff4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 register 24: uar t primecell identification 2 (uar tpcellid2), of fset 0xff8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 register 25: uar t primecell identification 3 (uar tpcellid3), of fset 0xffc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 june 14, 2007 16 luminary micro confidential-advance product information t able of contents
ssi ................................................................................................................................................. 325 register 1: ssi control 0 (ssicr0), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337 register 2: ssi control 1 (ssicr1), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 register 3: ssi data (ssidr), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 register 4: ssi status (ssisr), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 register 5: ssi clock prescale (ssicpsr), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342 register 6: ssi interrupt mask (ssiim), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 register 7: ssi raw interrupt status (ssiris), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344 register 8: ssi masked interrupt status (ssimis), of fset 0x01c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 register 9: ssi interrupt clear (ssiicr), of fset 0x020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 register 10: ssi peripheral identification 4 (ssiperiphid4), of fset 0xfd0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 register 1 1: ssi peripheral identification 5 (ssiperiphid5), of fset 0xfd4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 register 12: ssi peripheral identification 6 (ssiperiphid6), of fset 0xfd8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 register 13: ssi peripheral identification 7 (ssiperiphid7), of fset 0xfdc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 register 14: ssi peripheral identification 0 (ssiperiphid0), of fset 0xfe0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 register 15: ssi peripheral identification 1 (ssiperiphid1), of fset 0xfe4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 register 16: ssi peripheral identification 2 (ssiperiphid2), of fset 0xfe8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 register 17: ssi peripheral identification 3 (ssiperiphid3), of fset 0xfec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 register 18: ssi primecell identification 0 (ssipcellid0), of fset 0xff0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355 register 19: ssi primecell identification 1 (ssipcellid1), of fset 0xff4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356 register 20: ssi primecell identification 2 (ssipcellid2), of fset 0xff8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357 register 21: ssi primecell identification 3 (ssipcellid3), of fset 0xffc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 inter-integrated circuit (i 2 c) interface ........................................................................................ 359 register 1: i 2 c master slave address (i2cmsa), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373 register 2: i 2 c master control/status (i2cmcs), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 register 3: i 2 c master data (i2cmdr), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378 register 4: i 2 c master t imer period (i2cmtpr), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379 register 5: i 2 c master interrupt mask (i2cmimr), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 register 6: i 2 c master raw interrupt status (i2cmris), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381 register 7: i 2 c master masked interrupt status (i2cmmis), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382 register 8: i 2 c master interrupt clear (i2cmicr), of fset 0x01c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 register 9: i 2 c master configuration (i2cmcr), of fset 0x020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384 register 10: i 2 c slave own address (i2csoar), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386 register 1 1: i 2 c slave control/status (i2cscsr), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 register 12: i 2 c slave data (i2csdr), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389 register 13: i 2 c slave interrupt mask (i2csimr), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390 register 14: i 2 c slave raw interrupt status (i2csris), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391 register 15: i 2 c slave masked interrupt status (i2csmis), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392 register 16: i 2 c slave interrupt clear (i2csicr), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393 can ............................................................................................................................................... 394 register 1: can control (canctl), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 register 2: can status (cansts), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410 register 3: can error counter (canerr), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 register 4: can bit t iming (canbit), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 register 5: can interrupt (canint), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 register 6: can t est (cantst), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 register 7: can baud rate prescalar extension (canbrpe), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419 17 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 8: can if1 command request (canif1crq), of fset 0x020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420 register 9: can if2 command request (canif2crq), of fset 0x080 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420 register 10: can if1 command mask (canif1cmsk), of fset 0x024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 register 1 1: can if2 command mask (canif2cmsk), of fset 0x084 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 register 12: can if1 mask 1 (canif1msk1), of fset 0x028 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 register 13: can if2 mask 1 (canif2msk1), of fset 0x088 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 register 14: can if1 mask 2 (canif1msk2), of fset 0x02c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 register 15: can if2 mask 2 (canif2msk2), of fset 0x08c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 register 16: can if1 arbitration 1 (canif1arb1), of fset 0x030 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426 register 17: can if2 arbitration 1 (canif2arb1), of fset 0x090 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426 register 18: can if1 arbitration 2 (canif1arb2), of fset 0x034 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 register 19: can if2 arbitration 2 (canif2arb2), of fset 0x094 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 register 20: can if1 message control (canif1mctl), of fset 0x038 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 register 21: can if2 message control (canif2mctl), of fset 0x098 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 register 22: can if1 data a1 (canif1da1), of fset 0x03c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 register 23: can if2 data a1 (canif2da1), of fset 0x09c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 register 24: can if1 data a2 (canif1da2), of fset 0x040 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 register 25: can if2 data a2 (canif2da2), of fset 0x0a0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 register 26: can if1 data b1 (canif1db1), of fset 0x044 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 register 27: can if2 data b1 (canif2db1), of fset 0x0a4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 register 28: can if1 data b2 (canif1db2), of fset 0x048 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 register 29: can if2 data b2 (canif2db2), of fset 0x0a8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 register 30: can t ransmission request 1 (cantxrq1), of fset 0x100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 register 31: can t ransmission request 2 (cantxrq2), of fset 0x104 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 register 32: can new data 1 (cannwda1), of fset 0x120 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 register 33: can new data 2 (cannwda2), of fset 0x124 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 register 34: can message 1 interrupt pending (canmsg1int), of fset 0x140 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 register 35: can message 2 interrupt pending (canmsg2int), of fset 0x144 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 register 36: can message 1 v alid (canmsg1v al), of fset 0x160 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 register 37: can message 2 v alid (canmsg2v al), of fset 0x164 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 ethernet ........................................................................................................................................ 438 register 1: ethernet mac raw interrupt status (macris), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 register 2: ethernet mac interrupt acknowledge (maciack), of fset 0x000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449 register 3: ethernet mac interrupt mask (macim), of fset 0x004 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 register 4: ethernet mac receive control (macrctl), of fset 0x008 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451 register 5: ethernet mac t ransmit control (mactctl), of fset 0x00c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452 register 6: ethernet mac data (macda t a), of fset 0x010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453 register 7: ethernet mac individual address 0 (macia0), of fset 0x014 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454 register 8: ethernet mac individual address 1 (macia1), of fset 0x018 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 register 9: ethernet mac threshold (macthr), of fset 0x01c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456 register 10: ethernet mac management control (macmctl), of fset 0x020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 register 1 1: ethernet mac management divider (macmdv), of fset 0x024 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458 register 12: ethernet mac management address (macmadd), of fset 0x028 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 register 13: ethernet mac management t ransmit data (macmtxd), of fset 0x02c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460 register 14: ethernet mac management receive data (macmrxd), of fset 0x030 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 register 15: ethernet mac number of packets (macnp), of fset 0x034 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 register 16: ethernet mac t ransmission request (mactr), of fset 0x038 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 register 17: ethernet phy management register 0 C control (mr0), of fset 0x00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464 june 14, 2007 18 luminary micro confidential-advance product information t able of contents
register 18: ethernet phy management register 1 C status (mr1), of fset 0x01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466 register 19: ethernet phy management register 2 C phy identifier 1 (mr2), of fset 0x02 . . . . . . . . . . . . . . . . . . . . 468 register 20: ethernet phy management register 3 C phy identifier 2 (mr3), of fset 0x03 . . . . . . . . . . . . . . . . . . . . 469 register 21: ethernet phy management register 4 C auto-negotiation advertisement (mr4), of fset 0x04 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470 register 22: ethernet phy management register 5 C auto-negotiation link partner base page ability (mr5), of fset 0x05 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472 register 23: ethernet phy management register 6 C auto-negotiation expansion (mr6), of fset 0x06 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473 register 24: ethernet phy management register 16 C v endor-specific (mr16), of fset 0x10 . . . . . . . . . . . . . . . . . 474 register 25: ethernet phy management register 17 C interrupt control/status (mr17), of fset 0x1 1 . . . . . . 476 register 26: ethernet phy management register 18 C diagnostic (mr18), of fset 0x12 . . . . . . . . . . . . . . . . . . . . . . . . 478 register 27: ethernet phy management register 19 C t ransceiver control (mr19), of fset 0x13 . . . . . . . . . . . 479 register 28: ethernet phy management register 23 C led configuration (mr23), of fset 0x17 . . . . . . . . . . . . . 480 register 29: ethernet phy management register 24 Cmdi/mdix control (mr24), of fset 0x18 . . . . . . . . . . . . . . 481 analog comparators ................................................................................................................... 482 register 1: analog comparator masked interrupt status (acmis), of fset 0x00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488 register 2: analog comparator raw interrupt status (acris), of fset 0x04 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489 register 3: analog comparator interrupt enable (acinten), of fset 0x08 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 register 4: analog comparator reference v oltage control (acrefctl), of fset 0x10 . . . . . . . . . . . . . . . . . . . . . . . . . 491 register 5: analog comparator status 0 (acst a t0), of fset 0x20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 register 6: analog comparator status 1 (acst a t1), of fset 0x40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 register 7: analog comparator status 2 (acst a t2), of fset 0x60 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 register 8: analog comparator control 0 (acctl0), of fset 0x24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 register 9: analog comparator control 1 (acctl1), of fset 0x44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 register 10: analog comparator control 2 (acctl2), of fset 0x64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 19 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
about this document this data sheet provides reference information for the lm3s8938 microcontroller , describing the functional blocks of the system-on-chip (soc) device designed around the arm? cortex?-m3 core. audience this manual is intended for system software developers, hardware designers, and application developers. about this manual this document is organized into sections that correspond to each major feature. related documents the following documents are referenced by the data sheet, and available on the documentation cd or from the luminary micro web site at www .luminarymicro.com: arm? cortex?-m3 t echnical reference manual arm? coresight t echnical reference manual arm? v7-m architecture application level reference manual the following related documents are also referenced: ieee standard 1 149.1-t est access port and boundary-scan architecture this documentation list was current as of publication date. please check the luminary micro web site for additional documentation, including application notes and white papers. documentation conventions this document uses the conventions shown in t able 1 on page 20 . t able 1. documentation conventions meaning notation general register notation apb registers are indicated in uppercase bold. for example, pborctl is the power-on and brown-out reset control register . if a register name contains a lowercase n, it represents more than one register . for example, srcrn represents any (or all) of the three software reset control registers: srcr0, srcr1 , and srcr2 . register a single bit in a register . bit t wo or more consecutive and related bits. bit field a hexadecimal increment to a register's address, relative to that module's base address as specified in memory map on page 41 . of fset 0x nnn registers are numbered consecutively throughout the document to aid in referencing them. the register number has no meaning to software. register n june 14, 2007 20 luminary micro confidential-advance product information about this document
meaning notation register bits marked reserved are reserved for future use. in most cases, reserved bits are set to 0; however , user software should not rely on the value of a reserved bit. t o provide software compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. reserved the range of register bits inclusive from xx to yy . for example, 31:15 means bits 15 through 31 in that register . yy:xx this value in the register bit diagram indicates whether software running on the controller can change the value of the bit field. register bit/field t ypes software can read this field. the bit or field is cleared by hardware after reading the bit/field. rc software can read this field. always write the chip reset value. ro software can read or write this field. r/w software can read or write this field. a write of a 0 to a w1c bit does not af fect the bit value in the register . a write of a 1 clears the value of the bit in the register; the remaining bits remain unchanged. this register type is primarily used for clearing interrupt status bits where the read operation provides the interrupt status and the write of the read value clears only the interrupts being reported at the time the register was read. r/w1c software can write this field. a write of a 0 to a w1c bit does not af fect the bit value in the register . a write of a 1 clears the value of the bit in the register; the remaining bits remain unchanged. a read of the register returns no meaningful data. this register is typically used to clear the corresponding bit in an interrupt register . w1c only a write by software is valid; a read of the register returns no meaningful data. wo this value in the register bit diagram shows the bit/field value after any reset, unless noted. register bit/field reset v alue bit cleared to 0 on chip reset. 0 bit set to 1 on chip reset. 1 nondeterministic. - pin/signal notation pin alternate function; a pin defaults to the signal without the brackets. [ ] refers to the physical connection on the package. pin refers to the electrical signal encoding of a pin. signal change the value of the signal from the logically false state to the logically t rue state. for active high signals, the asserted signal value is 1 (high); for active low signals, the asserted signal value is 0 (low). the active polarity (high or low) is defined by the signal name (see signal and signal below). assert a signal change the value of the signal from the logically t rue state to the logically false state. deassert a signal signal names are in uppercase and in the courier font. an overbar on a signal name indicates that it is active low . t o assert signal is to drive it low; to deassert signal is to drive it high. signal signal names are in uppercase and in the courier font. an active high signal has no overbar . t o assert signal is to drive it high; to deassert signal is to drive it low . signal numbers an uppercase x indicates any of several values is allowed, where x can be any legal pattern. for example, a binary value of 0x00 can be either 0100 or 0000, a hex value of 0xx is 0x0 or 0x1, and so on. x hexadecimal numbers have a prefix of 0x. for example, 0x00ff is the hexadecimal number ff . binary numbers are indicated with a b suf fix, for example, 101 1b. decimal numbers are written without a prefix or suf fix. 0x 21 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
1 architectural overview the luminary micro stellaris ? family of microcontrollersthe first arm? cortex?-m3 based controllersbrings high-performance 32-bit computing to cost-sensitive embedded microcontroller applications. these pioneering parts deliver customers 32-bit performance at a cost equivalent to legacy 8- and 16-bit devices, all in a package with a small footprint. the stellaris ? family of fers ef ficient performance and extensive integration, favorably positioning the device into cost-conscious applications requiring significant control-processing and connectivity capabilities. the stellaris ? lm3s2000 series, designed for controller area network (can) applications, extends the stellaris family with bosch can networking technology , the golden standard in short-haul industrial networks. the stellaris ? lm3s2000 series also marks the first integration of can capabilities with the revolutionary cortex-m3 core. the stellaris ? lm3s6000 series combines both a 10/100 ethernet media access control (mac) and physical (phy) layer , marking the first time that integrated connectivity is available with an arm cortex-m3 mcu and the only integrated 10/100 ethernet mac and phy available in an arm architecture mcu. the lm3s8938 microcontroller is targeted for industrial applications, including remote monitoring, electronic point-of-sale machines, test and measurement equipment, network appliances and switches, factory automation, hv ac and building control, gaming equipment, motion control, medical instrumentation, and fire and security . for applications requiring extreme conservation of power , the lm3s8938 microcontroller features a battery-backed hibernation module to ef ficiently power down the lm3s8938 to a low-power state during extended periods of inactivity . with a power-up/power-down sequencer , a continuous time counter (r tc), a pair of match registers, an apb interface to the system bus, and dedicated non-volatile memory , the hibernation module positions the lm3s8938 microcontroller perfectly for battery applications. in addition, the lm3s8938 microcontroller of fers the advantages of arm's widely available development tools, system-on-chip (soc) infrastructure ip applications, and a large user community . additionally , the microcontroller uses arm's thumb?-compatible thumb-2 instruction set to reduce memory requirements and, thereby , cost. finally , the lm3s8938 microcontroller is code-compatible to all members of the extensive stellaris ? family; providing flexibility to fit our customers' precise needs. luminary micro of fers a complete solution to get to market quickly , with evaluation and development boards, white papers and application notes, an easy-to-use peripheral driver library , and a strong support, sales, and distributor network. 1.1 product features the lm3s8938 microcontroller includes the following product features: 32-bit risc performance C 32-bit arm? cortex?-m3 v7m architecture optimized for small-footprint embedded applications C system timer (syst ick), providing a simple, 24-bit clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism C thumb?-compatible thumb-2-only instruction set processor core for high code density C 50-mhz operation june 14, 2007 22 luminary micro confidential-advance product information architectural overview
C hardware-division and single-cycle-multiplication C integrated nested v ectored interrupt controller (nvic) providing deterministic interrupt handling C 34 interrupts with eight priority levels C memory protection unit (mpu), providing a privileged mode for protected operating system functionality C unaligned data access, enabling data to be ef ficiently packed into memory C atomic bit manipulation (bit-banding), delivering maximum memory utilization and streamlined peripheral control internal memory C 256 kb single-cycle flash ? user-managed flash block protection on a 2-kb block basis ? user-managed flash data programming ? user-defined and managed flash-protection block C 64 kb single-cycle sram general-purpose t imers C four general-purpose t imer modules (gptm), each of which provides two 16-bit timer/counters. each gptm can be configured to operate independently as timers or event counters (eight total): as a single 32-bit timer (four total), as one 32-bit real-t ime clock (r tc) to event capture, for pulse width modulation (pwm), or to trigger analog-to-digital conversions C 32-bit t imer modes ? programmable one-shot timer ? programmable periodic timer ? real-t ime clock when using an external 32.768-khz clock as the input ? user-enabled stalling in periodic and one-shot mode when the controller asserts the cpu halt flag during debug ? adc event trigger C 16-bit t imer modes ? general-purpose timer function with an 8-bit prescaler ? programmable one-shot timer ? programmable periodic timer ? user-enabled stalling when the controller asserts cpu halt flag during debug 23 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
? adc event trigger C 16-bit input capture modes ? input edge count capture ? input edge time capture C 16-bit pwm mode ? simple pwm mode with software-programmable output inversion of the pwm signal arm firm-compliant w atchdog t imer C 32-bit down counter with a programmable load register C separate watchdog clock with an enable C programmable interrupt generation logic with interrupt masking C lock register protection from runaway software C reset generation logic with an enable/disable C user-enabled stalling when the controller asserts the cpu halt flag during debug controller area network (can) C supports can protocol version 2.0 part a/b C bit rates up to 1mb/s C 32 message objects, each with its own identifier mask C maskable interrupt C disable automatic retransmission mode for ttcan C programmable loop-back mode for self-test operation 10/100 ethernet controller C conforms to the ieee 802.3-2002 specification C full- and half-duplex for both 100 mbps and 10 mbps operation C integrated 10/100 mbps t ransceiver (phy) C automatic mdi/mdi-x cross-over correction C programmable mac address C power-saving and power-down modes synchronous serial interface (ssi) C master or slave operation june 14, 2007 24 luminary micro confidential-advance product information architectural overview
C programmable clock bit rate and prescale C separate transmit and receive fifos, 16 bits wide, 8 locations deep C programmable interface operation for freescale spi, microwire, or t exas instruments synchronous serial interfaces C programmable data frame size from 4 to 16 bits C internal loopback test mode for diagnostic/debug testing uar t C three fully programmable 16c550-type uar t s with irda support C separate 16x8 transmit (tx) and 16x12 receive (rx) fifos to reduce cpu interrupt service loading C programmable baud-rate generator with fractional divider C programmable fifo length, including 1-byte deep operation providing conventional double-buf fered interface C fifo trigger levels of 1/8, ?, ?, ?, and 7/8 C standard asynchronous communication bits for start, stop, and parity C false-start-bit detection C line-break generation and detection adc C single- and dif ferential-input configurations C eight 10-bit channels (inputs) when used as single-ended inputs C sample rate of one million samples/second C flexible, configurable analog-to-digital conversion C four programmable sample conversion sequences from one to eight entries long, with corresponding conversion result fifos C each sequence triggered by software or internal event (timers, analog comparators, or gpio) C on-chip temperature sensor analog comparators C three independent integrated analog comparators C configurable for output to: drive an output pin, generate an interrupt, or initiate an adc sample sequence C compare external pin input to external pin input or to internal programmable voltage reference 25 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
i 2 c C t wo i 2 c modules C master and slave receive and transmit operation with transmission speed up to 100 kbps in standard mode and 400 kbps in fast mode C interrupt generation C master with arbitration and clock synchronization, multimaster support, and 7-bit addressing mode gpios C 3-38 gpios, depending on configuration C 5-v-tolerant input/outputs C programmable interrupt generation as either edge-triggered or level-sensitive C bit masking in both read and write operations through address lines C can initiate an adc sample sequence C programmable control for gpio pad configuration: ? w eak pull-up or pull-down resistors ? 2-ma, 4-ma, and 8-ma pad drive ? slew rate control for the 8-ma drive ? open drain enables ? digital input enables power C on-chip low drop-out (ldo) voltage regulator , with programmable output user-adjustable from 2.25 v to 2.75 v C hibernation module handles the power-up/down 3.3 v sequencing and control for the core digital logic and analog circuits C low-power options on controller: sleep and deep-sleep modes C low-power options for peripherals: software controls shutdown of individual peripherals C user-enabled ldo unregulated voltage detection and automatic reset C 3.3-v supply brown-out detection and reporting via interrupt or reset flexible reset sources C power-on reset (por) june 14, 2007 26 luminary micro confidential-advance product information architectural overview
C reset pin assertion C brown-out (bor) detector alerts to system power drops C software reset C w atchdog timer reset C internal low drop-out (ldo) regulator output goes unregulated additional features C six reset sources C programmable clock source control C clock gating to individual peripherals for power savings C ieee 1 149.1-1990 compliant t est access port (t ap) controller C debug access via jt ag and serial wire interfaces C full jt ag boundary scan industrial-range 100-pin rohs-compliant lqfp package 1.2 t arget applications remote monitoring electronic point-of-sale (pos) machines t est and measurement equipment network appliances and switches factory automation hv ac and building control gaming equipment motion control medical instrumentation fire and security power and energy t ransportation 1.3 high-level block diagram figure 1-1 on page 28 shows the features on the stellaris? fury-class family of devices. 27 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
figure 1-1. stellaris? fury-class high-level block diagram 1.4 functional overview the following sections provide an overview of the features of the lm3s8938 microcontroller . the page number in parenthesis indicates where that feature is discussed in detail. ordering and support information can be found in ordering and contact information on page 527 . june 14, 2007 28 luminary micro confidential-advance product information architectural overview ldo voltage regulator 3 analog comparators analog 10-bit adc 8 channel 1 msps temp sensor clocks, reset system control 4 timer/pwm/ccp each 32-bit or 2x16-bit watchdog timer gpios system battery-backed hibernate r t c systick timer 64 kb sram 256 kb flash 2 quadrature encoder inputs 6 pwm outputs motion control dead-band generator comparators pwm generator pwm interrupt timer 3 uarts 2 ssi/spi 10/100 ethernet mac + phy 2 can 2 i 2 c serial interfaces arm ? cortex ? -m3 50 mhz jtag nvic swd 32 32
1.4.1 arm cortex?-m3 1.4.1.1 processor core (see page 35 ) all members of the stellaris ? product family , including the lm3s8938 microcontroller , are designed around an arm cortex?-m3 processor core. the arm cortex-m3 processor provides the core for a high-performance, low-cost platform that meets the needs of minimal memory implementation, reduced pin count, and low-power consumption, while delivering outstanding computational performance and exceptional system response to interrupts. arm cortex-m3 processor core on page 35 provides an overview of the arm core; the core is detailed in the arm? cortex?-m3 t echnical reference manual . 1.4.1.2 system t imer (syst ick) cortex-m3 includes an integrated system timer , syst ick. syst ick provides a simple, 24-bit clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism. the counter can be used in several dif ferent ways, for example: an r t os tick timer which fires at a programmable rate (for example, 100 hz) and invokes a syst ick routine. a high-speed alarm timer using the system clock. a variable rate alarm or signal timerthe duration is range-dependent on the reference clock used and the dynamic range of the counter . a simple counter . software can use this to measure time to completion and time used. an internal clock source control based on missing/meeting durations. the countflag bit-field in the control and status register can be used to determine if an action completed within a set duration, as part of a dynamic clock management control loop. 1.4.1.3 nested v ectored interrupt controller (nvic) the lm3s8938 controller includes the arm nested v ectored interrupt controller (nvic) on the arm cortex-m3 core. the nvic and cortex-m3 prioritize and handle all exceptions. all exceptions are handled in handler mode. the processor state is automatically stored to the stack on an exception, and automatically restored from the stack at the end of the interrupt service routine (isr). the vector is fetched in parallel to the state saving, which enables ef ficient interrupt entry . the processor supports tail-chaining, which enables back-to-back interrupts to be performed without the overhead of state saving and restoration. software can set eight priority levels on 7 exceptions (system handlers) and 34 interrupts. interrupts on page 43 provides an overview of the nvic controller and the interrupt map. exceptions and interrupts are detailed in the arm? cortex?-m3 t echnical reference manual . 1.4.2 motor control peripherals t o enhance motor control, the lm3s8938 controller features pulse width modulation (pwm) outputs. 1.4.2.1 pwm (see page 202 ) pulse width modulation (pwm) is a powerful technique for digitally encoding analog signal levels. high-resolution counters are used to generate a square wave, and the duty cycle of the square wave is modulated to encode an analog signal. t ypical applications include switching power supplies and motor control. 29 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
on the lm3s8938, pwm motion control functionality can be achieved through the motion control features of the general-purpose timers (using the ccp pins). ccp pins (see page 202 ) the general-purpose t imer module's ccp (capture compare pwm) pins are software programmable to support a simple pwm mode with a software-programmable output inversion of the pwm signal. 1.4.3 serial communications peripherals the lm3s8938 controller supports both asynchronous and synchronous serial communications with: three fully programmable 16c550-type uar t s one ssi module t wo i 2 c modules one can unit 1.4.3.1 uart (see page 285 ) a universal asynchronous receiver/t ransmitter (uar t) is an integrated circuit used for rs-232c serial communications, containing a transmitter (parallel-to-serial converter) and a receiver (serial-to-parallel converter), each clocked separately . the lm3s8938 controller includes three fully programmable 16c550-type uar t s that support data transfer speeds up to 460.8 kbps. in addition, each uar t is capable of supporting irda. (although similar in functionality to a 16c550 uar t , it is not register-compatible.) separate 16x8 transmit (tx) and 16x12 receive (rx) fifos reduce cpu interrupt service loading. the uar t can generate individually masked interrupts from the rx, tx, modem status, and error conditions. the module provides a single combined interrupt when any of the interrupts are asserted and are unmasked. 1.4.3.2 ssi (see page 325 ) synchronous serial interface (ssi) is a four-wire bi-directional communications interface. the lm3s8938 controller includes one ssi module that provides the functionality for synchronous serial communications with peripheral devices, and can be configured to use the freescale spi, microwire , or ti synchronous serial interface frame formats. the size of the data frame is also configurable, and can be set between 4 and 16 bits, inclusive. the ssi module performs serial-to-parallel conversion on data received from a peripheral device, and parallel-to-serial conversion on data transmitted to a peripheral device. the tx and rx paths are buf fered with internal fifos, allowing up to eight 16-bit values to be stored independently . the ssi module can be configured as either a master or slave device. as a slave device, the ssi module can also be configured to disable its output, which allows a master device to be coupled with multiple slave devices. the ssi module also includes a programmable bit rate clock divider and prescaler to generate the output serial clock derived from the ssi module's input clock. bit rates are generated based on the input clock and the maximum bit rate is determined by the connected peripheral. june 14, 2007 30 luminary micro confidential-advance product information architectural overview
1.4.3.3 i 2 c(see page 359 ) the inter-integrated circuit (i 2 c) bus provides bi-directional data transfer through a two-wire design (a serial data line sda and a serial clock line scl). the i 2 c bus interfaces to external i 2 c devices such as serial memory (rams and roms), networking devices, lcds, tone generators, and so on. the i 2 c bus may also be used for system testing and diagnostic purposes in product development and manufacture. the lm3s8938 controller includes two i 2 c modules that provide the ability to communicate to other ic devices over an i 2 c bus. the i 2 c bus supports devices that can both transmit and receive (write and read) data. devices on the i 2 c bus can be designated as either a master or a slave. each i 2 c module supports both sending and receiving data as either a master or a slave, and also supports the simultaneous operation as both a master and a slave. the four i 2 c modes are: master t ransmit, master receive, slave t ransmit, and slave receive. a stellaris ? i 2 c module can operate at two speeds: standard (100 kbps) and fast (400 kbps). both the i 2 c master and slave can generate interrupts. the i 2 c master generates interrupts when a transmit or receive operation completes (or aborts due to an error). the i 2 c slave generates interrupts when data has been sent or requested by a master . 1.4.3.4 controller area network (see page 394 ) controller area network (can) is a multicast shared serial-bus standard for connecting electronic control units (ecus). can was specifically designed to be robust in electromagnetically noisy environments and can utilize a dif ferential balanced line like rs-485 or a more robust twisted-pair wire. originally created for automotive purposes, now it is used in many embedded control applications (for example, industrial or medical). bit rates up to 1mb/s are possible at network lengths below 40 meters. decreased bit rates allow longer network distances (for example, 125 kb/s at 500m). a transmitter sends a message to all can nodes (broadcasting). each node decides on the basis of the identifier received whether it should process the message. the identifier also determines the priority that the message enjoys in competition for bus access. each can message can transmit from 0 to 8 bytes of user information. the lm3s8938 includes one can units. 1.4.3.5 ethernet mac (see page 438 ) ethernet is a frame-based computer networking technology for local area networks (lans). ethernet has been standardized as ieee 802.3. it defines a number of wiring and signaling standards for the physical layer , two means of network access at the media access control (mac)/data link layer , and a common addressing format. the stellaris? ethernet controller consists of a fully integrated media access controller (mac) and network physical (phy) interface device. the ethernet controller conforms to ieee 802.3 specifications and fully supports 10base-t and 100base-tx standards. in addition, the ethernet controller supports automatic mdi/mdi-x cross-over correction. 1.4.4 system peripherals 1.4.4.1 programmable gpios (see page 155 ) general-purpose input/output (gpio) pins of fer flexibility for a variety of connections. 31 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
the stellaris ? gpio module is composed of seven physical gpio blocks, each corresponding to an individual gpio port. the gpio module is firm-compliant (compliant to the arm foundation ip for real-t ime microcontrollers specification) and supports 3-38 programmable input/output pins. the number of gpios available depends on the peripherals being used (see signal t ables on page 496 for the signals available to each gpio pin). the gpio module features programmable interrupt generation as either edge-triggered or level-sensitive on all pins, programmable control for gpio pad configuration, and bit masking in both read and write operations through address lines. 1.4.4.2 four programmable t imers (see page 196 ) programmable timers can be used to count or time external events that drive the t imer input pins. the stellaris ? general-purpose t imer module (gptm) contains four gptm blocks. each gptm block provides two 16-bit timer/counters that can be configured to operate independently as timers or event counters, or configured to operate as one 32-bit timer or one 32-bit real-t ime clock (r tc). t imers can also be used to trigger analog-to-digital (adc) conversions. when configured in 32-bit mode, a timer can run as a one-shot timer , periodic timer , or real-t ime clock (r tc). when in 16-bit mode, a timer can run as a one-shot timer or periodic timer , and can extend its precision by using an 8-bit prescaler . a 16-bit timer can also be configured for event capture or pulse width modulation (pwm) generation. 1.4.4.3 w atchdog t imer (see page 229 ) a watchdog timer can generate nonmaskable interrupts (nmis) or a reset when a time-out value is reached. the watchdog timer is used to regain control when a system has failed due to a software error or to the failure of an external device to respond in the expected way . the stellaris ? w atchdog t imer module consists of a 32-bit down counter , a programmable load register , interrupt generation logic, and a locking register . the w atchdog t imer can be configured to generate an interrupt to the controller on its first time-out, and to generate a reset signal on its second time-out. once the w atchdog t imer has been configured, the lock register can be written to prevent the timer configuration from being inadvertently altered. 1.4.5 memory peripherals the lm3s8938 controller of fers both sram and flash memory . 1.4.5.1 sram (see page 131 ) the lm3s8938 static random access memory (sram) controller supports 64 kb sram. the internal sram of the stellaris ? devices is located at of fset 0x0000.0000 of the device memory map. t o reduce the number of time-consuming read-modify-write (rmw) operations, arm has introduced bit-banding technology in the new cortex-m3 processor . with a bit-band-enabled processor , certain regions in the memory map (sram and peripheral space) can use address aliases to access individual bits in a single, atomic operation. 1.4.5.2 flash (see page 132 ) the lm3s8938 flash controller supports 256 kb of flash memory . the flash is organized as a set of 1-kb blocks that can be individually erased. erasing a block causes the entire contents of the block to be reset to all 1s. these blocks are paired into a set of 2-kb blocks that can be individually protected. the blocks can be marked as read-only or execute-only , providing dif ferent levels of code protection. read-only blocks cannot be erased or programmed, protecting the contents of those blocks from being modified. execute-only blocks cannot be erased or programmed, and can only june 14, 2007 32 luminary micro confidential-advance product information architectural overview
be read by the controller instruction fetch mechanism, protecting the contents of those blocks from being read by either the controller or by a debugger . 1.4.6 additional features 1.4.6.1 memory map (see page 41 ) a memory map lists the location of instructions and data in memory . the memory map for the lm3s8938 controller can be found in memory map on page 41 . register addresses are given as a hexadecimal increment, relative to the module's base address as shown in the memory map. the arm? cortex?-m3 t echnical reference manual provides further information on the memory map. 1.4.6.2 jt ag t ap controller (see page 46 ) the joint t est action group (jt ag) port provides a standardized serial interface for controlling the t est access port (t ap) and associated test logic. the t ap , jt ag instruction register , and jt ag data registers can be used to test the interconnects of assembled printed circuit boards, obtain manufacturing information on the components, and observe and/or control the inputs and outputs of the controller during normal operation. the jt ag port provides a high degree of testability and chip-level access at a low cost. the jt ag port is comprised of the standard five pins: trst , tck , tms , tdi , and tdo . data is transmitted serially into the controller on tdi and out of the controller on tdo . the interpretation of this data is dependent on the current state of the t ap controller . for detailed information on the operation of the jt ag port and t ap controller , please refer to the ieee standard 1 149.1-t est access port and boundary-scan architecture . the luminary micro jt ag controller works with the arm jt ag controller built into the cortex-m3 core. this is implemented by multiplexing the tdo outputs from both jt ag controllers. arm jt ag instructions select the arm tdo output while luminary micro jt ag instructions select the luminary micro tdo outputs. the multiplexer is controlled by the luminary micro jt ag controller , which has comprehensive programming for the arm, luminary micro, and unimplemented jt ag instructions. 1.4.6.3 system control and clocks (see page 57 ) system control determines the overall operation of the device. it provides information about the device, controls the clocking of the device and individual peripherals, and handles reset detection and reporting. 1.4.6.4 hibernation module (see page 113 ) the hibernation module provides logic to switch power of f to the main processor and peripherals, and to wake on external or time-based events. the hibernation module includes power-sequencing logic, a real-time clock with a pair of match registers, low-battery detection circuitry , and interrupt signalling to the processor . it also includes 64 32-bit words of non-volatile memory that can be used for saving state during hibernation. 1.4.7 hardware details details on the pins and package can be found in the following sections: pin diagram on page 495 signal t ables on page 496 33 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
operating characteristics on page 510 electrical characteristics on page 511 package information on page 525 june 14, 2007 34 luminary micro confidential-advance product information architectural overview
2 arm cortex-m3 processor core the arm cortex-m3 processor provides the core for a high-performance, low-cost platform that meets the needs of minimal memory implementation, reduced pin count, and low power consumption, while delivering outstanding computational performance and exceptional system response to interrupts. features include: compact core. thumb-2 instruction set, delivering the high-performance expected of an arm core in the memory size usually associated with 8- and 16-bit devices; typically in the range of a few kilobytes of memory for microcontroller class applications. speedy application execution through harvard architecture characterized by separate buses for instruction and data. exceptional interrupt handling, by implementing the register manipulations required for handling an interrupt in hardware. memory protection unit (mpu) to provide a privileged mode of operation for complex applications. migration from the arm7(tm) processor family for better performance and power ef ficiency . full-featured debug solution with a: C serial wire jt ag debug port (swj-dp) C flash patch and breakpoint (fpb) unit for implementing breakpoints C data w atchpoint and t rigger (dwt) unit for implementing watchpoints, trigger resources, and system profiling C instrumentation t race macrocell (itm) for support of printf style debugging C t race port interface unit ( tpiu) for bridging to a t race port analyzer the stellaris ? family of microcontrollers builds on this core to bring high-performance 32-bit computing to cost-sensitive embedded microcontroller applications, such as factory automation and control, industrial control power devices, building and home automation, and stepper motors. for more information on the arm cortex-m3 processor core, see the arm? cortex?-m3 t echnical reference manual . for information on swj-dp , see the arm? coresight t echnical reference manual . 35 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
2.1 block diagram figure 2-1. cpu block diagram 2.2 functional description important: the arm? cortex?-m3 t echnical reference manual describes all the features of an arm cortex-m3 in detail. however , these features dif fer based on the implementation. this section describes the stellaris ? implementation. luminary micro has implemented the arm cortex-m3 core as shown in figure 2-1 on page 36 . as noted in the arm? cortex?-m3 t echnical reference manual , several cortex-m3 components are flexible in their implementation: sw/jt ag-dp , etm, tpiu, the rom table, the mpu, and the nested v ectored interrupt controller (nvic). each of these is addressed in the sections that follow . 2.2.1 serial w ire and jt ag debug luminary micro has replaced the arm sw-dp and jt ag-dp with the arm coresight?-compliant serial wire jt ag debug port (swj-dp) interface. this means chapter 12, debug port, of the arm? cortex?-m3 t echnical reference manual does not apply to stellaris ? devices. the swj-dp interface combines the swd and jt ag debug ports into one module. see the coresight? design kit t echnical reference manual for details on swj-dp . june 14, 2007 36 luminary micro confidential-advance product information arm cortex-m3 processor core private peripheral bus ( internal) data w atchpoint and t race interrupts debug sleep instrumentation t race macrocell t race port interface unit cm3 core instructions data flash patch and breakpoint memory protection unit adv . high- perf . bus access port nested v ectored interrupt controller serial wire jt ag debug port bus matrix adv . peripheral bus i-code bus d-code bus system bus rom t able private peripheral bus ( external) serial wire output t race port ( swo) arm cortex -m3
2.2.2 embedded t race macrocell (etm) etm was not implemented in the stellaris ? devices. this means chapters 15 and 16 of the arm? cortex?-m3 t echnical reference manual can be ignored. 2.2.3 t race port interface unit (tpiu) the tpiu acts as a bridge between the cortex-m3 trace data from the itm, and an of f-chip t race port analyzer . the stellaris ? devices have implemented tpiu as shown in figure 2-2 on page 37 . this is similar to the non-etm version described in the arm? cortex?-m3 t echnical reference manual , however , swj-dp only provides swv output for the tpiu. figure 2-2. tpiu block diagram 2.2.4 rom t able the default rom table was implemented as described in the arm? cortex?-m3 t echnical reference manual . 2.2.5 memory protection unit (mpu) the memory protection unit (mpu) is included on the lm3s8938 controller and supports the standard armv7 protected memory system architecture (pmsa) model. the mpu provides full support for protection regions, overlapping protection regions, access permissions, and exporting memory attributes to the system. 2.2.6 nested v ectored interrupt controller (nvic) the nested v ectored interrupt controller (nvic): facilitates low-latency exception and interrupt handling 37 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller a tb interface asynchronous fifo apb interface t race out ( serializer) debug a tb slave port apb slave port serial wire t race port ( swo)
controls power management implements system control registers the nvic supports up to 240 dynamically reprioritizable interrupts each with up to 256 levels of priority . the nvic and the processor core interface are closely coupled, which enables low latency interrupt processing and ef ficient processing of late arriving interrupts. the nvic maintains knowledge of the stacked (nested) interrupts to enable tail-chaining of interrupts. y ou can only fully access the nvic from privileged mode, but you can pend interrupts in user-mode if you enable the configuration control register (see the arm? cortex?-m3 t echnical reference manual). any other user-mode access causes a bus fault. all nvic registers are accessible using byte, halfword, and word unless otherwise stated. all nvic registers and system debug registers are little endian regardless of the endianness state of the processor . 2.2.6.1 interrupts the arm? cortex?-m3 t echnical reference manual describes the maximum number of interrupts and interrupt priorities. the lm3s8938 microcontroller supports 34 interrupts with eight priority levels. 2.2.6.2 system t imer (syst ick) cortex-m3 includes an integrated system timer , syst ick. syst ick provides a simple, 24-bit clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism. the counter can be used in several dif ferent ways, for example: an r t os tick timer which fires at a programmable rate (for example 100 hz) and invokes a syst ick routine. a high-speed alarm timer using the system clock. a variable rate alarm or signal timerthe duration is range-dependent on the reference clock used and the dynamic range of the counter . a simple counter . software can use this to measure time to completion and time used. an internal clock source control based on missing/meeting durations. the countflag bit-field in the control and status register can be used to determine if an action completed within a set duration, as part of a dynamic clock management control loop. functional description the timer consists of three registers: a control and status counter to configure its clock, enable the counter , enable the syst ick interrupt, and determine counter status. the reload value for the counter , used to provide the counter's wrap value. the current value of the counter . a fourth register , the syst ick calibration v alue register , is not implemented in the stellaris devices. june 14, 2007 38 luminary micro confidential-advance product information arm cortex-m3 processor core
when enabled, the timer counts down from the reload value to zero, reloads (wraps) to the value in the syst ick reload v alue register on the next clock edge, then decrements on subsequent clocks. w riting a value of zero to the reload v alue register disables the counter on the next wrap. when the counter reaches zero, the countflag status bit is set. the countflag bit clears on reads. w riting to the current v alue register clears the register and the countflag status bit. the write does not trigger the syst ick exception logic. on a read, the current value is the value of the register at the time the register is accessed. if the core is in debug state (halted), the counter will not decrement. the timer is clocked with respect to a reference clock. the reference clock can be the core clock or an external clock source. syst ick control and status register use the syst ick control and status register to enable the syst ick features. the reset is 0x0000.0000. description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:17 returns 1 if timer counted to 0 since last time this was read. clears on read by application. if read by the debugger using the dap , this bit is cleared on read-only if the mastert ype bit in the ahb-ap control register is set to 0. otherwise, the countflag bit is not changed by the debugger read. 0 r/w countflag 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 r/w reserved 15:3 0 = external reference clock. (not implemented for stellaris microcontrollers.) 1 = core clock. if no reference clock is provided, it is held at 1 and so gives the same time as the core clock. the core clock must be at least 2.5 times faster than the reference clock. if it is not, the count values are unpredictable. 0 r/w clksource 2 1 = counting down to 0 pends the syst ick handler . 0 = counting down to 0 does not pend the syst ick handler . software can use the countflag to determine if ever counted to 0. 0 r/w tickint 1 1 = counter operates in a multi-shot way . that is, counter loads with the reload value and then begins counting down. on reaching 0, it sets the countflag to 1 and optionally pends the syst ick handler , based on tickint . it then loads the reload value again, and begins counting. 0 = counter disabled. 0 r/w enable 0 syst ick reload v alue register use the syst ick reload v alue register to specify the start value to load into the current value register when the counter reaches 0. it can be any value between 1 and 0x00ffffff . a start value of 0 is possible, but has no ef fect because the syst ick interrupt and countflag are activated when counting from 1 to 0. therefore, as a multi-shot timer , repeated over and over , it fires every n+1 clock pulse, where n is any value from 1 to 0x00ffffff . so, if the tick interrupt is required every 100 clock pulses, 99 must be written into the reload. if a new value is written on each tick interrupt, so treated as single shot, then the actual count down must be written. for example, if a tick is next required after 400 clock pulses, 400 must be written into the reload. 39 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:24 v alue to load into the syst ick current v alue register when the counter reaches 0. - w1c reload 23:0 syst ick current v alue register use the syst ick current v alue register to find the current value in the register . description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:24 current value at the time the register is accessed. no read-modify-write protection is provided, so change with care. this register is write-clear . w riting to it with any value clears the register to 0. clearing this register also clears the countflag bit of the syst ick control and status register . - w1c current 23:0 syst ick calibration v alue register the syst ick calibration v alue register is not implemented. june 14, 2007 40 luminary micro confidential-advance product information arm cortex-m3 processor core
3 memory map the memory map for the lm3s8938 controller is provided in t able 3-1 on page 41 . in this manual, register addresses are given as a hexadecimal increment, relative to the module s base address as shown in the memory map. see also chapter 4, memory map in the arm? cortex?-m3 t echnical reference manual . note: in t able 3-1 on page 41 addresses not listed are reserved. t able 3-1. memory map a for details on registers, see page ... description end start memory 135 on-chip flash b 0x1fff .ffff 0x0000.0000 135 bit-banded on-chip sram c 0x200f .ffff 0x2000.0000 - reserved non-bit-banded sram space 0x21ff .ffff 0x2010.0000 131 bit-band alias of 0x2000.0000 through 0x200f .ffff 0x23ff .ffff 0x2200.0000 - reserved non-bit-banded sram space 0x3fff .ffff 0x2400.0000 firm peripherals 231 w atchdog timer 0x4000.0fff 0x4000.0000 - reserved 0x4000.3fff 0x4000.1000 161 gpio port a 0x4000.4fff 0x4000.4000 161 gpio port b 0x4000.5fff 0x4000.5000 161 gpio port c 0x4000.6fff 0x4000.6000 161 gpio port d 0x4000.7fff 0x4000.7000 336 ssi0 0x4000.8fff 0x4000.8000 - reserved 0x4000.bfff 0x4000.a000 292 uar t0 0x4000.cfff 0x4000.c000 292 uar t1 0x4000.dfff 0x4000.d000 292 uar t2 0x4000.efff 0x4000.e000 - reserved 0x4000.ffff 0x4000.f000 - reserved for future firm peripherals 0x4001.ffff 0x4001.0000 peripherals 372 i2c master 0 0x4002.07ff 0x4002.0000 385 i2c slave 0 0x4002.0fff 0x4002.0800 372 i2c master 1 0x4002.17ff 0x4002.1000 385 i2c slave 1 0x4002.1fff 0x4001.1800 - reserved 0x4002.3fff 0x4002.2000 161 gpio port e 0x4002.4fff 0x4002.4000 161 gpio port f 0x4002.5fff 0x4002.5000 161 gpio port g 0x4002.6fff 0x4002.6000 - reserved 0x4002.bfff 0x4002.9000 - reserved 0x4002.ffff 0x4002.e000 41 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
for details on registers, see page ... description end start 207 t imer0 0x4003.0fff 0x4003.0000 207 t imer1 0x4003.1fff 0x4003.1000 207 t imer2 0x4003.2fff 0x4003.2000 207 t imer3 0x4003.3fff 0x4003.3000 - reserved 0x4003.7fff 0x4003.4000 258 adc 0x4003.8fff 0x4003.8000 - reserved 0x4003.bfff 0x4003.9000 482 analog comparators 0x4003.cfff 0x4003.c000 - reserved 0x4003.ffff 0x4003.d000 407 can0 controller 0x4004.0fff 0x4004.0000 - reserved 0x4004.7fff 0x4004.3000 446 ethernet controller 0x4004.8fff 0x4004.8000 - reserved 0x4004.bfff 0x4004.9000 - reserved 0x400f .bfff 0x4004.c000 118 hibernation module 0x400f .cfff 0x400f .c000 135 flash control 0x400f .dfff 0x400f .d000 64 system control 0x400f .efff 0x400f .e000 - reserved 0x400f .ffff 0x400f .f000 - reserved 0x401 1.1fff 0x401 1.1000 - reserved for non bit-banded peripheral space 0x41ff .ffff 0x4012.0000 - bit-banded alias of 0x4000.0000 through 0x400f .ffff 0x43ff .ffff 0x4200.0000 - reserved for non bit-banded peripheral space 0x5e32.ffff 0x4400.0000 - reserved 0x5fff .ffff 0x5e34.0000 - reserved for external devices 0xdfff .ffff 0x6000.0000 private peripheral bus arm? cortex?-m3 t echnical reference manual instrumentation t race macrocell (itm) 0xe000.0fff 0xe000.0000 data w atchpoint and t race (dwt) 0xe000.1fff 0xe000.1000 flash patch and breakpoint (fpb) 0xe000.2fff 0xe000.2000 reserved 0xe000.dfff 0xe000.3000 nested v ectored interrupt controller (nvic) 0xe000.efff 0xe000.e000 reserved 0xe003.ffff 0xe000.f000 t race port interface unit (tpiu) 0xe004.0fff 0xe004.0000 - reserved 0xe004.1fff 0xe004.1000 - reserved 0xe00f .ffff 0xe004.2000 - reserved for vendor peripherals 0xffff .ffff 0xe010.0000 a. all reserved space returns a bus fault when read or written. b. the unavailable flash will bus fault throughout this range. c. the unavailable sram will bus fault throughout this range. june 14, 2007 42 luminary micro confidential-advance product information memory map
4 interrupts the arm cortex-m3 processor and the nested v ectored interrupt controller (nvic) prioritize and handle all exceptions. all exceptions are handled in handler mode. the processor state is automatically stored to the stack on an exception, and automatically restored from the stack at the end of the interrupt service routine (isr). the vector is fetched in parallel to the state saving, which enables ef ficient interrupt entry . the processor supports tail-chaining, which enables back-to-back interrupts to be performed without the overhead of state saving and restoration. t able 4-1 on page 43 lists all the exceptions. software can set eight priority levels on seven of these exceptions (system handlers) as well as on 34 interrupts (listed in t able 4-2 on page 44 ). priorities on the system handlers are set with the nvic system handler priority registers. interrupts are enabled through the nvic interrupt set enable register and prioritized with the nvic interrupt priority registers. y ou can also group priorities by splitting priority levels into pre-emption priorities and subpriorities. all the interrupt registers are described in chapter 8, nested v ectored interrupt controller in the arm? cortex?-m3 t echnical reference manual . internally , the highest user-settable priority (0) is treated as fourth priority , after a reset, nmi, and a hard fault. note that 0 is the default priority for all the settable priorities. if you assign the same priority level to two or more interrupts, their hardware priority (the lower the position number) determines the order in which the processor activates them. for example, if both gpio port a and gpio port b are priority level 1, then gpio port a has higher priority . see chapter 5, exceptions and chapter 8, nested v ectored interrupt controller in the arm? cortex?-m3 t echnical reference manual for more information on exceptions and interrupts. note: in t able 4-2 on page 44 interrupts not listed are reserved. t able 4-1. exception t ypes description priority a position exception t ype stack top is loaded from first entry of vector table on reset. - 0 - invoked on power up and warm reset. on first instruction, drops to lowest priority (and then is called the base level of activation). this is asynchronous. -3 (highest) 1 reset cannot be stopped or preempted by any exception but reset. this is asynchronous. an nmi is only producible by software, using the nvic interrupt control state register . -2 2 non-maskable interrupt (nmi) all classes of fault, when the fault cannot activate due to priority or the configurable fault handler has been disabled. this is synchronous. -1 3 hard fault mpu mismatch, including access violation and no match. this is synchronous. the priority of this exception can be changed. settable 4 memory management pre-fetch fault, memory access fault, and other address/memory related faults. this is synchronous when precise and asynchronous when imprecise. y ou can enable or disable this fault. settable 5 bus fault usage fault, such as undefined instruction executed or illegal state transition attempt. this is synchronous. settable 6 usage fault reserved. - 7-10 - system service call with svc instruction. this is synchronous. settable 1 1 svcall 43 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description priority a position exception t ype debug monitor (when not halting). this is synchronous, but only active when enabled. it does not activate if lower priority than the current activation. settable 12 debug monitor reserved. - 13 - pendable request for system service. this is asynchronous and only pended by software. settable 14 pendsv system tick timer has fired. this is asynchronous. settable 15 syst ick asserted from outside the arm cortex-m3 core and fed through the nvic (prioritized). these are all asynchronous. t able 4-2 on page 44 lists the interrupts on the lm3s8938 controller . settable 16 and above interrupts a. 0 is the default priority for all the settable priorities. t able 4-2. interrupts description interrupt (bit in interrupt registers) gpio port a 0 gpio port b 1 gpio port c 2 gpio port d 3 gpio port e 4 uar t0 5 uar t1 6 ssi0 7 i2c0 8 adc sequence 0 14 adc sequence 1 15 adc sequence 2 16 adc sequence 3 17 w atchdog timer 18 t imer0 a 19 t imer0 b 20 t imer1 a 21 t imer1 b 22 t imer2 a 23 t imer2 b 24 analog comparator 0 25 analog comparator 1 26 analog comparator 2 27 system control 28 flash control 29 gpio port f 30 gpio port g 31 uar t2 33 t imer3 a 35 t imer3 b 36 june 14, 2007 44 luminary micro confidential-advance product information interrupts
description interrupt (bit in interrupt registers) i2c1 37 can0 39 ethernet controller 42 hibernation module 43 reserved 44-47 45 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
5 jt ag interface the joint t est action group (jt ag) port is an ieee standard that defines a t est access port and boundary scan architecture for digital integrated circuits and provides a standardized serial interface for controlling the associated test logic. the t ap , instruction register (ir), and data registers (dr) can be used to test the interconnections of assembled printed circuit boards and obtain manufacturing information on the components. the jt ag port also provides a means of accessing and controlling design-for-test features such as i/o pin observation and control, scan testing, and debugging. the jt ag port is comprised of the standard five pins: trst , tck , tms , tdi , and tdo . data is transmitted serially into the controller on tdi and out of the controller on tdo . the interpretation of this data is dependent on the current state of the t ap controller . for detailed information on the operation of the jt ag port and t ap controller , please refer to the ieee standard 1 149.1-t est access port and boundary-scan architecture . the luminary micro jt ag controller works with the arm jt ag controller built into the cortex-m3 core. this is implemented by multiplexing the tdo outputs from both jt ag controllers. arm jt ag instructions select the arm tdo output while luminary micro jt ag instructions select the luminary micro tdo outputs. the multiplexer is controlled by the luminary micro jt ag controller , which has comprehensive programming for the arm, lmi, and unimplemented jt ag instructions. the jt ag module has the following features: ieee 1 149.1-1990 compatible t est access port (t ap) controller four-bit instruction register (ir) chain for storing jt ag instructions ieee standard instructions: C byp ass instruction C idcode instruction C sample/preload instruction C extest instruction C intest instruction arm additional instructions: C ap acc instruction C dp acc instruction C abor t instruction integrated arm serial wire debug (swd) see the arm? cortex?-m3 t echnical reference manual for more information on the arm jt ag controller . june 14, 2007 46 luminary micro confidential-advance product information jt ag interface
5.1 block diagram figure 5-1. jt ag module block diagram 5.2 functional description a high-level conceptual drawing of the jt ag module is shown in figure 5-1 on page 47 . the jt ag module is composed of the t est access port (t ap) controller and serial shift chains with parallel update registers. the t ap controller is a simple state machine controlled by the trst , tck and tms inputs. the current state of the t ap controller depends on the current value of trst and the sequence of values captured on tms at the rising edge of tck . the t ap controller determines when the serial shift chains capture new data, shift data from tdi towards tdo , and update the parallel load registers. the current state of the t ap controller also determines whether the instruction register (ir) chain or one of the data register (dr) chains is being accessed. the serial shift chains with parallel load registers are comprised of a single instruction register (ir) chain and multiple data register (dr) chains. the current instruction loaded in the parallel load register determines which dr chain is captured, shifted, or updated during the sequencing of the t ap controller . some instructions, like extest and intest , operate on data currently in a dr chain and do not capture, shift, or update any of the chains. instructions that are not implemented decode to the byp ass instruction to ensure that the serial path between tdi and tdo is always connected (see t able 5-2 on page 53 for a list of implemented instructions). see jt ag and boundary scan on page 521 for jt ag timing diagrams. 47 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller instr uction register (ir) t ap controller byp ass data register boundar y scan data register idcode data register abor t data register dp a cc data register ap a cc data register trst tck tms tdi tdo cor te x-m3 deb ug p or t
5.2.1 jt ag interface pins the jt ag interface consists of five standard pins: trst , tck , tms , tdi , and tdo . these pins and their associated reset state are given in t able 5-1 on page 48 . detailed information on each pin follows. t able 5-1. jt ag port pins reset state drive v alue drive strength internal pull-down internal pull-up data direction pin name n/a n/a disabled enabled input trst n/a n/a disabled enabled input tck n/a n/a disabled enabled input tms n/a n/a disabled enabled input tdi high-z 2-ma driver disabled enabled output tdo 5.2.1.1 t est reset input ( trst ) the trst pin is an asynchronous active low input signal for initializing and resetting the jt ag t ap controller and associated jt ag circuitry . when trst is asserted, the t ap controller resets to the t est-logic-reset state and remains there while trst is asserted. when the t ap controller enters the t est-logic-reset state, the jt ag instruction register (ir) resets to the default instruction, idcode. by default, the internal pull-up resistor on the trst pin is enabled after reset. changes to the pull-up resistor settings on gpio port b should ensure that the internal pull-up resistor remains enabled on pb7 / trst ; otherwise jt ag communication could be lost. 5.2.1.2 t est clock input (tck) the tck pin is the clock for the jt ag module. this clock is provided so the test logic can operate independently of any other system clocks. in addition, it ensures that multiple jt ag t ap controllers that are daisy-chained together can synchronously communicate serial test data between components. during normal operation, tck is driven by a free-running clock with a nominal 50% duty cycle. when necessary , tck can be stopped at 0 or 1 for extended periods of time. while tck is stopped at 0 or 1, the state of the t ap controller does not change and data in the jt ag instruction and data registers is not lost. by default, the internal pull-up resistor on the tck pin is enabled after reset. this assures that no clocking occurs if the pin is not driven from an external source. the internal pull-up and pull-down resistors can be turned of f to save internal power as long as the tck pin is constantly being driven by an external source. 5.2.1.3 t est mode select (tms) the tms pin selects the next state of the jt ag t ap controller . tms is sampled on the rising edge of tck . depending on the current t ap state and the sampled value of tms , the next state is entered. because the tms pin is sampled on the rising edge of tck , the ieee standard 1 149.1 expects the value on tms to change on the falling edge of tck . holding tms high for five consecutive tck cycles drives the t ap controller state machine to the t est-logic-reset state. when the t ap controller enters the t est-logic-reset state, the jt ag instruction register (ir) resets to the default instruction, idcode. therefore, this sequence can be used as a reset mechanism, similar to asserting trst . the jt ag t est access port state machine can be seen in its entirety in figure 5-2 on page 50 . june 14, 2007 48 luminary micro confidential-advance product information jt ag interface
by default, the internal pull-up resistor on the tms pin is enabled after reset. changes to the pull-up resistor settings on gpio port c should ensure that the internal pull-up resistor remains enabled on pc1/tms ; otherwise jt ag communication could be lost. 5.2.1.4 t est data input (tdi) the tdi pin provides a stream of serial information to the ir chain and the dr chains. tdi is sampled on the rising edge of tck and, depending on the current t ap state and the current instruction, presents this data to the proper shift register chain. because the tdi pin is sampled on the rising edge of tck , the ieee standard 1 149.1 expects the value on tdi to change on the falling edge of tck . by default, the internal pull-up resistor on the tdi pin is enabled after reset. changes to the pull-up resistor settings on gpio port c should ensure that the internal pull-up resistor remains enabled on pc2/tdi ; otherwise jt ag communication could be lost. 5.2.1.5 t est data output (tdo) the tdo pin provides an output stream of serial information from the ir chain or the dr chains. the value of tdo depends on the current t ap state, the current instruction, and the data in the chain being accessed. in order to save power when the jt ag port is not being used, the tdo pin is placed in an inactive drive state when not actively shifting out data. because tdo can be connected to the tdi of another controller in a daisy-chain configuration, the ieee standard 1 149.1 expects the value on tdo to change on the falling edge of tck . by default, the internal pull-up resistor on the tdo pin is enabled after reset. this assures that the pin remains at a constant logic level when the jt ag port is not being used. the internal pull-up and pull-down resistors can be turned of f to save internal power if a high-z output value is acceptable during certain t ap controller states. 5.2.2 jt ag t ap controller the jt ag t ap controller state machine is shown in figure 5-2 on page 50 . the t ap controller state machine is reset to the t est-logic-reset state on the assertion of a power-on-reset (por) or the assertion of trst . asserting the correct sequence on the tms pin allows the jt ag module to shift in new instructions, shift in data, or idle during extended testing sequences. for detailed information on the function of the t ap controller and the operations that occur in each state, please refer to ieee standard 1 149.1 . 49 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
figure 5-2. t est access port state machine 5.2.3 shift registers the shift registers consist of a serial shift register chain and a parallel load register . the serial shift register chain samples specific information during the t ap controller s capture states and allows this information to be shifted out of tdo during the t ap controller s shift states. while the sampled data is being shifted out of the chain on tdo , new data is being shifted into the serial shift register on tdi . this new data is stored in the parallel load register during the t ap controller s upda te states. each of the shift registers is discussed in detail in register descriptions on page 53 . 5.2.4 operational considerations there are certain operational considerations when using the jt ag module. because the jt ag pins can be programmed to be gpios, board configuration and reset conditions on these pins must be considered. in addition, because the jt ag module has integrated arm serial wire debug, the method for switching between these two operational modes is described below . june 14, 2007 50 luminary micro confidential-advance product information jt ag interface t est logic reset run t est idle select dr scan select ir scan capture dr capture ir shift dr shift ir exit 1 dr exit 1 ir exit 2 dr exit 2 ir pause dr pause ir update dr update ir 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
5.2.4.1 gpio functionality when the controller is reset with either a por or rst , the jt ag/swd port pins default to their jt ag/swd configurations. the default configuration includes enabling digital functionality (setting gpioden to 1), enabling the pull-up resistors (setting gpiopur to 1), and enabling the alternate hardware function (setting gpioafsel to 1) for the pb7 and pc[3:0] jt ag/swd pins. it is possible for software to configure these pins as gpios after reset by writing 0s to pb7 and pc[3:0] in the gpioafsel register . if the user does not require the jt ag/swd port for debugging or board-level testing, this provides five more gpios for use in the design. caution C if the jt ag pins ar e used as gpios in a design, pb7 and pc2 cannot have external pull-down r esistors connected to both of them at the same time. if both pins ar e pulled low during r eset, the contr oller has unpr edictable behavior . if this happens, r emove one or both of the pull-down r esistors, and apply rst or power-cycle the part. in addition, it is possible to cr eate a softwar e sequence that pr events the debugger fr om connecting to the stellaris ? micr ocontr oller . if the pr ogram code loaded into fash immediately changes the jt ag pins to their gpio functionality , the debugger may not have enough time to connect and halt the contr oller befor e the jt ag pin functionality switches. this may lock the debugger out of the part. this can be avoided with a softwar e r outine that r estor es jt ag functionality based on an external or softwar e trigger . the commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. w rites to protected bits of the gpio alternate function select (gpioafsel) register (see page 171 ) are not committed to storage unless the gpio lock (gpiolock) register (see page 181 ) has been unlocked and the appropriate bits of the gpio commit (gpiocr) register (see page 182 ) have been set to 1. recovering a "locked" device if software configures any of the jt ag/swd pins as gpio and loses the ability to communicate with the debugger , there is a debug sequence that can be used to recover the device. performing a total of ten jt ag-to-swd and swd-to-jt ag switch sequences while holding the device in reset mass erases the flash memory . the sequence to recover the device is: 1. assert and hold the rst signal. 2. perform the jt ag-to-swd switch sequence. 3. perform the swd-to-jt ag switch sequence. 4. perform the jt ag-to-swd switch sequence. 5. perform the swd-to-jt ag switch sequence. 6. perform the jt ag-to-swd switch sequence. 7. perform the swd-to-jt ag switch sequence. 8. perform the jt ag-to-swd switch sequence. 9. perform the swd-to-jt ag switch sequence. 10. perform the jt ag-to-swd switch sequence. 1 1. perform the swd-to-jt ag switch sequence. 51 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
12. release the rst signal. the jt ag-to-swd and swd-to-jt ag switch sequences are described in arm serial wire debug (swd) on page 52 . when performing switch sequences for the purpose of recovering the debug capabilities of the device, only steps 1 and 2 of the switch sequence need to be performed. 5.2.4.2 arm serial w ire debug (swd) in order to seamlessly integrate the arm serial wire debug (swd) functionality , a serial-wire debugger must be able to connect to the cortex-m3 core without having to perform, or have any knowledge of, jt ag cycles. this is accomplished with a swd preamble that is issued before the swd session begins. the preamble used to enable the swd interface of the swj-dp module starts with the t ap controller in the t est-logic-reset state. from here, the preamble sequences the t ap controller through the following states: run t est idle, select dr, select ir, t est logic reset, t est logic reset, run t est idle, run t est idle, select dr, select ir, t est logic reset, t est logic reset, run t est idle, run t est idle, select dr, select ir, and t est logic reset states. stepping through this sequences of the t ap state machine enables the swd interface and disables the jt ag interface. for more information on this operation and the swd interface, see the arm? cortex?-m3 t echnical reference manual and the arm? coresight t echnical reference manual . because this sequence is a valid series of jt ag operations that could be issued, the arm jt ag t ap controller is not fully compliant to the ieee standard 1 149.1 . this is the only instance where the arm jt ag t ap controller does not meet full compliance with the specification. due to the low probability of this sequence occurring during normal operation of the t ap controller , it should not af fect normal performance of the jt ag interface. jt ag-to-swd switching t o switch the operating mode of the debug access port (dap) from jt ag to swd mode, the external debug hardware must send a switch sequence to the device. the 16-bit switch sequence for switching to swd mode is defined as b1 1 1001 1 1 1001 1 1 10, transmitted lsb first. this can also be represented as 16'he79e when transmitted lsb first. the complete switch sequence should consist of the following transactions on the tck / swclk and tms / swdio signals: 1. send at least 50 tck / swclk cycles with tms / swdio set to 1. this ensures that both jt ag and swd are in their reset/idle states. 2. send the 16-bit jt ag-to-swd switch sequence, 16'he79e. 3. send at least 50 tck / swclk cycles with tms / swdio set to 1. this ensures that if swj-dp was already in swd mode, before sending the switch sequence, the swd goes into the line reset state. swd-to-jt ag switching t o switch the operating mode of the debug access port (dap) from swd to jt ag mode, the external debug hardware must send a switch sequence to the device. the 16-bit switch sequence for switching to jt ag mode is defined as b1 1 1001 1 1 1001 1 1 10, transmitted lsb first. this can also be represented as 16'he73c when transmitted lsb first. the complete switch sequence should consist of the following transactions on the tck / swclk and tms / swdio signals: 1. send at least 50 tck / swclk cycles with tms / swdio set to 1. this ensures that both jt ag and swd are in their reset/idle states. june 14, 2007 52 luminary micro confidential-advance product information jt ag interface
2. send the 16-bit swd-to-jt ag switch sequence, 16'he73c. 3. send at least 5 tck / swclk cycles with tms / swdio set to 1. this ensures that if swj-dp was already in jt ag mode, before sending the switch sequence, the jt ag goes into the t est logic reset state. 5.3 initialization and configuration after a power-on-reset or an external reset ( rst ), the jt ag pins are automatically configured for jt ag communication. no user-defined initialization or configuration is needed. however , if the user application changes these pins to their gpio function, they must be configured back to their jt ag functionality before jt ag communication can be restored. this is done by enabling the five jt ag pins ( pb7 and pc[3:0] ) for their alternate function using the gpioafsel register . 5.4 register descriptions there are no apb-accessible registers in the jt ag t ap controller or shift register chains. the registers within the jt ag controller are all accessed serially through the t ap controller . the registers can be broken down into two main categories: instruction registers and data registers. 5.4.1 instruction register (ir) the jt ag t ap instruction register (ir) is a four-bit serial scan chain with a parallel load register connected between the jt ag tdi and tdo pins. when the t ap controller is placed in the correct states, bits can be shifted into the instruction register . once these bits have been shifted into the chain and updated, they are interpreted as the current instruction. the decode of the instruction register bits is shown in t able 5-2 on page 53 . a detailed explanation of each instruction, along with its associated data register , follows. t able 5-2. jt ag instruction register commands description instruction ir[3:0] drives the values preloaded into the boundary scan chain by the sample/preload instruction onto the pads. extest 0000 drives the values preloaded into the boundary scan chain by the sample/preload instruction into the controller . intest 0001 captures the current i/o values and shifts the sampled values out of the boundary scan chain while new preload data is shifted in. sample / preload 0010 shifts data into the arm debug port abort register . abor t 1000 shifts data into and out of the arm dp access register . dp acc 1010 shifts data into and out of the arm ac access register . ap acc 101 1 loads manufacturing information defined by the ieee standard 1 149.1 into the idcode chain and shifts it out. idcode 1 1 10 connects tdi to tdo through a single shift register chain. byp ass 1 1 1 1 defaults to the byp ass instruction to ensure that tdi is always connected to tdo . reserved all others 5.4.1.1 extest instruction the extest instruction does not have an associated data register chain. the extest instruction uses the data that has been preloaded into the boundary scan data register using the sample/preload instruction. when the extest instruction is present in the instruction register , the preloaded data in the boundary scan data register associated with the outputs and output enables are used to drive the gpio pads rather than the signals coming from the core. this allows 53 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
tests to be developed that drive known values out of the controller , which can be used to verify connectivity . 5.4.1.2 intest instruction the intest instruction does not have an associated data register chain. the intest instruction uses the data that has been preloaded into the boundary scan data register using the sample/preload instruction. when the intest instruction is present in the instruction register , the preloaded data in the boundary scan data register associated with the inputs are used to drive the signals going into the core rather than the signals coming from the gpio pads. this allows tests to be developed that drive known values into the controller , which can be used for testing. it is important to note that although the rst input pin is on the boundary scan data register chain, it is only observable. 5.4.1.3 sample/preload instruction the sample/preload instruction connects the boundary scan data register chain between tdi and tdo . this instruction samples the current state of the pad pins for observation and preloads new test data. each gpio pad has an associated input, output, and output enable signal. when the t ap controller enters the capture dr state during this instruction, the input, output, and output-enable signals to each of the gpio pads are captured. these samples are serially shifted out of tdo while the t ap controller is in the shift dr state and can be used for observation or comparison in various tests. while these samples of the inputs, outputs, and output enables are being shifted out of the boundary scan data register , new data is being shifted into the boundary scan data register from tdi . once the new data has been shifted into the boundary scan data register , the data is saved in the parallel load registers when the t ap controller enters the update dr state. this update of the parallel load register preloads data into the boundary scan data register that is associated with each input, output, and output enable. this preloaded data can be used with the extest and intest instructions to drive data into or out of the controller . please see boundary scan data register on page 56 for more information. 5.4.1.4 abort instruction the abor t instruction connects the associated abor t data register chain between tdi and tdo . this instruction provides read and write access to the abor t register of the arm debug access port (dap). shifting the proper data into this data register clears various error bits or initiates a dap abort of a previous request. please see the abor t data register on page 56 for more information. 5.4.1.5 dp acc instruction the dp acc instruction connects the associated dp acc data register chain between tdi and tdo . this instruction provides read and write access to the dp acc register of the arm debug access port (dap). shifting the proper data into this register and reading the data output from this register allows read and write access to the arm debug and status registers. please see dp acc data register on page 56 for more information. 5.4.1.6 ap acc instruction the ap acc instruction connects the associated ap acc data register chain between tdi and tdo . this instruction provides read and write access to the ap acc register of the arm debug access port (dap). shifting the proper data into this register and reading the data output from this register allows read and write access to internal components and buses through the debug port. please see ap acc data register on page 56 for more information. june 14, 2007 54 luminary micro confidential-advance product information jt ag interface
5.4.1.7 idcode instruction the idcode instruction connects the associated idcode data register chain between tdi and tdo . this instruction provides information on the manufacturer , part number , and version of the arm core. this information can be used by testing equipment and debuggers to automatically configure their input and output data streams. idcode is the default instruction that is loaded into the jt ag instruction register when a power-on-reset (por) is asserted, trst is asserted, or the t est-logic-reset state is entered. please see idcode data register on page 55 for more information. 5.4.1.8 byp ass instruction the byp ass instruction connects the associated byp ass data register chain between tdi and tdo . this instruction is used to create a minimum length serial path between the tdi and tdo ports. the byp ass data register is a single-bit shift register . this instruction improves test ef ficiency by allowing components that are not needed for a specific test to be bypassed in the jt ag scan chain by loading them with the byp ass instruction. please see byp ass data register on page 55 for more information. 5.4.2 data registers the jt ag module contains six data registers. these include: idcode, byp ass, boundary scan, ap acc, dp acc, and abor t serial data register chains. each of these data registers is discussed in the following sections. 5.4.2.1 idcode data register the format for the 32-bit idcode data register defined by the ieee standard 1 149.1 is shown in figure 5-3 on page 55 . the standard requires that every jt ag-compliant device implement either the idcode instruction or the byp ass instruction as the default instruction. the lsb of the idcode data register is defined to be a 1 to distinguish it from the byp ass instruction, which has an lsb of 0. this allows auto configuration test tools to determine which instruction is the default instruction. the major uses of the jt ag port are for manufacturer testing of component assembly , and program development and debug. t o facilitate the use of auto-configuration debug tools, the idcode instruction outputs a value of 0x3ba00477. this value indicates an arm cortex-m3, v ersion 1 processor . this allows the debuggers to automatically configure themselves to work correctly with the cortex-m3 during debug. figure 5-3. idcode register format 5.4.2.2 byp ass data register the format for the 1-bit byp ass data register defined by the ieee standard 1 149.1 is shown in figure 5-4 on page 56 . the standard requires that every jt ag-compliant device implement either the byp ass instruction or the idcode instruction as the default instruction. the lsb of the byp ass data register is defined to be a 0 to distinguish it from the idcode instruction, which has an lsb of 1. this allows auto configuration test tools to determine which instruction is the default instruction. 55 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
figure 5-4. byp ass register format 5.4.2.3 boundary scan data register the format of the boundary scan data register is shown in figure 5-5 on page 56 . each gpio pin, in a counter-clockwise direction from the jt ag port pins, is included in the boundary scan data register . each gpio pin has three associated digital signals that are included in the chain. these signals are input, output, and output enable, and are arranged in that order as can be seen in the figure. in addition to the gpio pins, the controller reset pin, rst , is included in the chain. because the reset pin is always an input, only the input signal is included in the data register chain. when the boundary scan data register is accessed with the sample/preload instruction, the input, output, and output enable from each digital pad are sampled and then shifted out of the chain to be verified. the sampling of these values occurs on the rising edge of tck in the capture dr state of the t ap controller . while the sampled data is being shifted out of the boundary scan chain in the shift dr state of the t ap controller , new data can be preloaded into the chain for use with the extest and intest instructions. these instructions either force data out of the controller , with the extest instruction, or into the controller , with the intest instruction. figure 5-5. boundary scan register format for detailed information on the order of the input, output, and output enable bits for each of the gpio ports, please refer to the stellaris ? family boundary scan description language (bsdl) files, downloadable from www .luminarymicro.com. 5.4.2.4 ap acc data register the format for the 35-bit ap acc data register defined by arm is described in the arm? cortex?-m3 t echnical reference manual . 5.4.2.5 dp acc data register the format for the 35-bit dp acc data register defined by arm is described in the arm? cortex?-m3 t echnical reference manual . 5.4.2.6 abort data register the format for the 35-bit abor t data register defined by arm is described in the arm? cortex?-m3 t echnical reference manual . june 14, 2007 56 luminary micro confidential-advance product information jt ag interface o t d o t d i o i n e u t o o i n e u t o o i n e u t o o i n e u t i n ... ... r s t g p i o p b 6 g p i o m g p i o m + 1 g p i o n
6 system control system control determines the overall operation of the device. it provides information about the device, controls the clocking to the core and individual peripherals, and handles reset detection and reporting. 6.1 functional description the system control module provides the following capabilities: device identification, see device identification on page 57 local control, such as reset (see reset control on page 57 ), power (see power control on page 60 ) and clock control (see clock control on page 60 ) system control (run, sleep, and deep-sleep modes), see system control on page 62 6.1.1 device identification seven read-only registers provide software with information on the microcontroller , such as version, part number , sram size, flash size, and other features. see the did0 , did1 , and dc0 - dc4 registers. 6.1.2 reset control this section discusses aspects of hardware functions during reset as well as system software requirements following the reset sequence. 6.1.2.1 cmod0 and cmod1 t est-mode control pins t wo pins, cmod0 and cmod1 , are defined for use by luminary micro for testing the devices during manufacture. they have no end-user function and should not be used. the cmod pins should be connected to ground. 6.1.2.2 reset sources the controller has five sources of reset: 1. external reset input pin ( rst ) assertion, see rst pin assertion on page 57 . 2. power-on reset (por), see power-on reset (por) on page 58 . 3. internal brown-out (bor) detector , see brown-out reset (bor) on page 58 . 4. software-initiated reset (with the software reset registers), see software reset on page 59 . 5. a watchdog timer reset condition violation, see w atchdog t imer reset on page 59 . after a reset, the reset cause (resc) register is set with the reset cause. the bits in this register are sticky and maintain their state across multiple reset sequences, except when an internal por is the cause, and then all the other bits in the resc register are cleared except for the por indicator . 6.1.2.3 rst pin assertion the external reset pin ( rst ) resets the controller . this resets the core and all the peripherals except the jt ag t ap controller (see jt ag interface on page 46 ). the external reset sequence is as follows: 57 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
1. the external reset pin ( rst ) is asserted and then de-asserted. 2. the internal reset is released and the core loads from memory the initial stack pointer , the initial program counter , the first instruction designated by the program counter , and begins execution. a few clocks cycles from rst de-assertion to the start of the reset sequence is necessary for synchronization. the external reset timing is shown in figure 22-1 1 on page 523 . 6.1.2.4 power-on reset (por) the power-on reset (por) circuit monitors the power supply voltage (v dd ). the por circuit generates a reset signal to the internal logic when the power supply ramp reaches a threshold value (v th ). if the application only uses the por circuit, the rst input needs to be connected to the power supply (v dd ) through a pull-up resistor (1k to 10k ?). the device must be operating within the specified operating parameters at the point when the on-chip power-on reset pulse is complete. the 3.3-v power supply to the device must reach 3.0 v within 10 msec of it crossing 2.0 v to guarantee proper operation. for applications that require the use of an external reset to hold the device in reset longer than the internal por, the rst input may be used with the circuit as shown in figure 6-1 on page 58 . figure 6-1. external circuitry to extend reset the r 1 and c 1 components define the power-on delay . the r 2 resistor mitigates any leakage from the rst input. the diode (d 1 ) discharges c 1 rapidly when the power supply is turned of f. the power-on reset sequence is as follows: 1. the controller waits for the later of external reset ( rst ) or internal por to go inactive. 2. the internal reset is released and the core loads from memory the initial stack pointer , the initial program counter , the first instruction designated by the program counter , and begins execution. the internal por is only active on the initial power-up of the controller . the power-on reset timing is shown in figure 22-12 on page 524 . note: the power-on reset also resets the jt ag controller . an external reset does not. 6.1.2.5 brown-out reset (bor) a drop in the input voltage resulting in the assertion of the internal brown-out detector can be used to reset the controller . this is initially disabled and may be enabled by software. the system provides a brown-out detection circuit that triggers if the power supply (v dd ) drops below a brown-out threshold voltage (v bth ). if a brown-out condition is detected, the system may generate a controller interrupt or a system reset. june 14, 2007 58 luminary micro confidential-advance product information system control r 1 c 1 r 2 rst stellaris d 1
brown-out resets are controlled with the power-on and brown-out reset control (pborctl) register . the borior bit in the pborctl register must be set for a brown-out condition to trigger a reset. the brown-out reset is equivelent to an assertion of the external rst input and the reset is held active until the proper v dd level is restored. the resc register can be examined in the reset interrupt handler to determine if a brown-out condition was the cause of the reset, thus allowing software to determine what actions are required to recover . the internal brown-out reset timing is shown in figure 22-13 on page 524 . 6.1.2.6 software reset software can generate a reset to the entire system or may reset a specific peripheral. peripherals can be individually reset by software via three registers that control reset signals to each peripheral (see the srcrn registers). if the bit position corresponding to a peripheral is set, the peripheral is reset. the encoding of the reset registers is consistent with the encoding of the clock gating control for peripherals and on-chip functions (see system control on page 62 ). w riting a bit lane with a value of 1 initiates a reset of the corresponding unit. note that all reset signals for all clocks of the specified unit are asserted as a result of a software-initiated reset. the entire system can be reset by software by setting the sysresetreq bit in the cortex-m3 application interrupt and reset control register resets the entire system including the core. the software-initiated system reset sequence is as follows: 1. a software system reset is initiated by writing the sysresetreq bit in the arm cortex-m3 application interrupt and reset control register . 2. an internal reset is asserted. 3. the internal reset is deasserted and the controller loads from memory the initial stack pointer , the initial program counter , and the first instruction designated by the program counter , and then begins execution. the software-initiated system reset timing is shown in figure 22-14 on page 524 . 6.1.2.7 w atchdog t imer reset the watchdog timer module's function is to prevent system hangs. the watchdog timer can be configured to generate an interrupt to the controller on its first time-out, and to generate a reset signal on its second time-out. after the first time-out event, the 32-bit counter is reloaded with the value of the w atchdog t imer load (wdtload) register , and the timer resumes counting down from that value. if the timer counts down to its zero state again before the first time-out interrupt is cleared, and the reset signal has been enabled, the watchdog timer asserts its reset signal to the system. the watchdog timer reset sequence is as follows: 1. the watchdog timer times out for the second time without being serviced. 2. an internal reset is asserted. 3. the internal reset is released and the controller loads from memory the initial stack pointer , the initial program counter , the first instruction designated by the program counter , and begins execution. 59 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
the watchdog reset timing is shown in figure 22-15 on page 524 . 6.1.3 power control the stellaris ? microcontroller provides an integrated ldo regulator that may be used to provide power to the majority of the controller's internal logic. the ldo regulator provides software a mechanism to adjust the regulated value, in small increments (vstep), over the range of 2.25 v to 2.75 v (inclusive)or 2.5 v 10%. the adjustment is made by changing the value of the vadj field in the ldo power control (ldopctl) register . note: the use of the ldo is optional. the internal logic may be supplied by the on-chip ldo or by an external regulator . if the ldo is used, the ldo output pin is connected to the vdd25 pins on the printed circuit board. the ldo requires decoupling capacitors on the printed circuit board. if an external regulator is used, it is strongly recommended that the external regulator supply the controller only and not be shared with other devices on the printed circuit board. 6.1.4 clock control system control determines the control of clocks in this part. 6.1.4.1 fundamental clock sources there are four clock sources for use in the device: internal oscillator (iosc): the internal oscillator is an on-chip clock source. it does not require the use of any external components. the frequency of the internal oscillator is 12 mhz 30%. applications that do not depend on accurate clock sources may use this clock source to reduce system cost. the internal oscillator is the clock source the device uses during and following por. if the main oscillator is required, software must enable the main oscillator following reset and allow the main oscillator to stabilize before changing the clock reference. main oscillator: the main oscillator provides a frequency-accurate clock source by one of two means: an external single-ended clock source is connected to the osc0 input pin, or an external crystal is connected across the osc0 input and osc1 output pins. the crystal value allowed depends on whether the main oscillator is used as the clock reference source to the pll. if so, the crystal must be one of the supported frequencies between 3.579545 mhz through 8.192 mhz (inclusive). if the pll is not being used, the crystal may be any one of the supported frequencies between 1 mhz and 8.192 mhz. the single-ended clock source range is from dc through the specified speed of the device. the supported crystals are listed in t able 6-3 on page 75 . internal 30-khz oscillator: the internal 30-khz oscillator is similar to the internal oscillator , except that it provides an operational frequency of 30 khz 30%. it is intended for use during deep-sleep power-saving modes. this power-savings mode benefits from reduced internal switching and also allows the main oscillator to be powered down. external real-time oscillator: the external real-time oscillator provides a low-frequency , accurate clock reference. it is intended to provide the system with a real-time clock source. the real-time oscillator is part of the hibernation module ( hibernation module on page 113 ) and may also provide an accurate source of deep-sleep or hibernate mode power savings. the internal system clock (sysclk), is derived from any of the four sources plus two others: the output of the internal pll, and the internal oscillator divided by four (3 mhz 30%). the frequency of the pll clock reference must be in the range of 3.579545 mhz to 8.192 mhz (inclusive). june 14, 2007 60 luminary micro confidential-advance product information system control
the run-mode clock configuration (rcc) and run-mode clock configuration 2 (rcc2) registers provide control for the system clock. the rcc2 register is provided to extend fields that of fer additional encodings over the rcc register . when used, the rcc2 register field values are used by the logic over the corresponding field in the rcc register . in particular , rcc2 provides for a larger assortment of clock configuration options. 6.1.4.2 crystal configuration for the main oscillator (mosc) the main oscillator supports the use of a select number of crystals in the range of 1 mhz through 8.192 mhz. this method allows luminary micro to provide the best possible pll settings. t able 6-3 on page 75 describes the available crystal choices and default programming values. software configures the rcc register xtal field with the crystal number . if the pll is used in the design, the xtal field value is internally translated to the pll settings. 6.1.4.3 pll frequency configuration the pll is disabled by default during power-on reset and is enabled later by software if required. software configures the pll input reference clock source, specifies the output divisor to set the system clock frequency , and enables the pll to drive the output. if the main oscillator provides the clock reference to the pll, the translation provided by hardware and used to program the pll is available for software in the xt al to pll t ranslation (pllcfg) register (see page 77 ). the internal translation provides a translation within 1% of the targetted pll vco frequency . t able 6-3 on page 75 describes the available crystal choices and default programming of the pllcfg register . the crystal number is written into the xtal field of the run-mode clock configuration (rcc) register . any time the xtal field changes, the new settings are translated and the internal pll settings are updated. 6.1.4.4 pll modes the pll has two modes of operation: normal and power-down normal: the pll multiplies the input clock reference and drives the output. power-down: most of the pll internal circuitry is disabled and the pll does not drive the output. the modes are programmed using the rcc / rcc2 register fields (see page 73 and page 78 ). 6.1.4.5 pll operation if the pll configuration is changed, the pll output frequency is unstable until it reconverges (relocks) to the new setting. the time between the configuration change and relock is t ready (see t able 22-5 on page 513 ). during this time, the pll is not usable as a clock reference. the pll is changed by one of the following: change to the xtal value in the rcc registerwrites of the same value do not cause a relock. change in the pll from power-down to normal mode. a counter is defined to measure the t ready requirement. the counter is clocked by the main oscillator . the range of the main oscillator has been taken into account and the down counter is set to 0x1200 (that is, ~600 s at a 8.192 mhz external oscillator clock). hardware is provided to keep the pll from being used as a system clock until the t ready condition is met after one of the two 61 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
changes above. it is the user's responsibility to have a stable clock source (like the main oscillator) before the rcc / rcc2 register is switched to use the pll. 6.1.5 system control for power-savings purposes, the rcgcn , scgcn , and dcgcn registers control the clock gating logic for each peripheral or block in the system while the controller is in run, sleep, and deep-sleep mode, respectively . in run mode, the processor executes code. in sleep mode, the clock frequency of the active peripherals is unchanged, but the processor is not clocked and therefore no longer executes code. in deep-sleep mode, the clock frequency of the active peripherals may change (depending on the run mode clock configuration) in addition to the processor clock being stopped. an interrupt returns the device to run mode from one of the sleep modes; the sleep modes are entered on request from the code. each mode is described in more detail below . there are four levels of operation for the device defined as: run mode. run mode provides normal operation of the processor and all of the peripherals that are currently enabled by the rcgcn registers. the system clock can be any of the available clock sources including the pll. sleep mode. sleep mode is entered by the cortex-m3 core executing a wfi (wait for interrupt) instruction. any properly configured interrupt event in the system will bring the processor back into run mode. see the system control nvic section of the arm? cortex?-m3 t echnical reference manual for more details. in sleep mode, the cortex-m3 processor core and the memory subsystem are not clocked. peripherals are clocked that are enabled in the scgcn register when auto-clock gating is enabled (see the rcc register) or the rcgcn register when the auto-clock gating is disabled. the system clock has the same source and frequency as that during run mode. deep-sleep mode. deep-sleep mode is entered by first writing the deep sleep enable bit in the arm cortex-m3 nvic system control register and then executing a wfi instruction. any properly configured interrupt event in the system will bring the processor back into run mode. see the system control nvic section of the arm? cortex?-m3 t echnical reference manual for more details. the cortex-m3 processor core and the memory subsystem are not clocked. peripherals are clocked that are enabled in the dcgcn register when auto-clock gating is enabled (see the rcc register) or the rcgcn register when auto-clock gating is disabled. the system clock source is the main oscillator by default or the internal oscillator specified in the dslpclkcfg register if one is enabled. when the dslpclkcfg register is used, the internal oscillator is powered up, if necessary , and the main oscillator is powered down. if the pll is running at the time of the wfi instruction, hardware will power the pll down and override the sysdiv field of the active rcc / rcc2 register to be /16 or /64, respectively . when the deep-sleep exit event occurs, hardware brings the system clock back to the source and frequency it had at the onset of deep-sleep mode before enabling the clocks that had been stopped during the deep-sleep duration. hibernate mode. in this mode, the power supplies are turned of f to the main part of the device and only the hibernation module's circuitry is active. an external wake event or r tc event is required to bring the device back to run mode. the cortex-m3 processor and peripherals outside of the hibernation module see a normal "power on" sequence and the processor starts running june 14, 2007 62 luminary micro confidential-advance product information system control
code. it can determine that it has been restarted from hibernate mode by inspecting the hibernation module registers. 6.2 initialization and configuration the pll is configured using direct register writes to the rcc / rcc2 register . if the rcc2 register is being used, the usercc2 bit must be set and the appropriate rcc2 bit/field is used. the steps required to successfully change the pll-based system clock are: 1. bypass the pll and system clock divider by setting the bypass bit and clearing the usesys bit in the rcc register . this configures the system to run of f a raw clock source (using the main oscillator or internal oscillator) and allows for the new pll configuration to be validated before switching the system clock to the pll. 2. select the crystal value ( xtal ) and oscillator source ( oscsrc ), and clear the pwrdn bit in rcc / rcc2 . setting the xtal field automatically pulls valid pll configuration data for the appropriate crystal, and clearing the pwrdn bit powers and enables the pll and its output. 3. select the desired system divider ( sysdiv ) in rcc / rcc2 and set the usesys bit in rcc . the sysdiv field determines the system frequency for the microcontroller . 4. w ait for the pll to lock by polling the plllris bit in the raw interrupt status (ris ) register . 5. enable use of the pll by clearing the bypass bit in rcc / rcc2 . 6.3 register map t able 6-1 on page 63 lists the system control registers, grouped by function. the of fset listed is a hexadecimal increment to the register s address, relative to the system control base address of 0x400f .e000. note: spaces in the system control register space that are not used are reserved for future or internal use by luminary micro, inc. software should not modify any reserved memory address. note: a bv in the reset column indicates the reset value is a build v alue and part-specific. see the page number referenced for the reset value description. t able 6-1. system control register map see page description reset t ype name offset 65 device identification 0 - ro did0 0x000 81 device identification 1 - ro did1 0x004 83 device capabilities 0 0x00ff .007f ro dc0 0x008 84 device capabilities 1 0x0101.33ff ro dc1 0x010 86 device capabilities 2 0x070f .5017 ro dc2 0x014 88 device capabilities 3 0x3fff .7fc0 ro dc3 0x018 90 device capabilities 4 0x5100.007f ro dc4 0x01c 67 brown-out reset control 0x0000.7ffd r/w pborctl 0x030 63 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
see page description reset t ype name offset 68 ldo power control 0x0000.0000 r/w ldopctl 0x034 109 software reset control 0 0x00000000 r/w srcr0 0x040 110 software reset control 1 0x00000000 r/w srcr1 0x044 112 software reset control 2 0x00000000 r/w srcr2 0x048 69 raw interrupt status 0x0000.0000 ro ris 0x050 70 interrupt mask control 0x0000.0000 r/w imc 0x054 71 masked interrupt status and clear 0x0000.0000 r/w1c misc 0x058 72 reset cause - r/w resc 0x05c 73 run-mode clock configuration 0x07a0.3ad1 r/w rcc 0x060 77 xt al to pll t ranslation - ro pllcfg 0x064 78 run-mode clock configuration 2 0x0780.2800 r/w rcc2 0x070 91 run mode clock gating control register 0 0x00000040 r/w rcgc0 0x100 97 run mode clock gating control register 1 0x00000000 r/w rcgc1 0x104 103 run mode clock gating control register 2 0x00000000 r/w rcgc2 0x108 93 sleep mode clock gating control register 0 0x00000040 r/w scgc0 0x1 10 99 sleep mode clock gating control register 1 0x00000000 r/w scgc1 0x1 14 105 sleep mode clock gating control register 2 0x00000000 r/w scgc2 0x1 18 95 deep sleep mode clock gating control register 0 0x00000040 r/w dcgc0 0x120 101 deep sleep mode clock gating control register 1 0x00000000 r/w dcgc1 0x124 107 deep sleep mode clock gating control register 2 0x00000000 r/w dcgc2 0x128 80 deep sleep clock configuration 0x0780.0000 r/w dslpclkcfg 0x144 6.4 register descriptions all addresses given are relative to the system control base address of 0x400f .e000. june 14, 2007 64 luminary micro confidential-advance product information system control
register 1: device identification 0 (did0), offset 0x000 this register identifies the version of the device. device identification 0 (did0) base 0x400f .e000 of fset 0x000 t ype ro, reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 class reserved ver reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 minor major ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype - - - - - - - - - - - - - - - - reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31 this field defines the did0 register format version. the version number is numeric. the value of the ver field is encoded as follows: description v alue first revision of the did0 register format, for stellaris? fury-class devices. 1 1 ro ver 30:28 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 27:24 the class field value identifies the internal design from which all mask sets are generated for all devices in a particular product line. the class field value is changed for new product lines, for changes in fab process (for example, a remap or shrink), or any case where the major or minor fields require dif ferentiation from prior devices. the value of the class field is encoded as follows (all other encodings are reserved): description v alue stellaris? sandstorm-class devices. 0 stellaris? fury-class devices. 1 1 ro class 23:16 65 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this field specifies the major revision number of the device. the major revision reflects changes to base layers of the design. the major revision number is indicated in the part number as a letter (a for first revision, b for second, and so on). this field is encoded as follows: description v alue revision a (initial device) 0 revision b (first base layer revision) 1 revision c (second base layer revision) 2 and so on. - ro major 15:8 this field specifies the minor revision number of the device. the minor revision reflects changes to the metal layers of the design. the minor field value is reset when the major field is changed. this field is numeric and is encoded as follows: description v alue initial device, or a major revision update. 0 first metal layer change. 1 second metal layer change. 2 and so on. - ro minor 7:0 june 14, 2007 66 luminary micro confidential-advance product information system control
register 2: brown-out reset control (pborctl), offset 0x030 this register is responsible for controlling reset conditions after initial power-on reset. brown-out reset control (pborctl) base 0x400f .e000 of fset 0x030 t ype r/w , reset 0x0000.7ffd 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved borior reserved ro r/w ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:2 bor interrupt or reset this bit controls how a bor event is signaled to the controller . if set, a reset is signaled. otherwise, an interrupt is signaled. 0 r/w borior 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 0 67 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: ldo power control (ldopctl), offset 0x034 the vadj field in this register adjusts the on-chip output voltage (v out ). ldo power control (ldopctl) base 0x400f .e000 of fset 0x034 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 v adj reserved r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:6 this field sets the on-chip output voltage. the programming values for the vadj field are provided in t able 6-2 on page 68 . 0x0 r/w v adj 5:0 t able 6-2. v adj to vout v out (v) v adj v alue v out (v) v adj v alue v out (v) v adj v alue 2.35 0x03 2.55 0x1f 2.75 0x1b 2.30 0x04 2.50 0x00 2.70 0x1c 2.25 0x05 2.45 0x01 2.65 0x1d reserved 0x06-0x3f 2.40 0x02 2.60 0x1e june 14, 2007 68 luminary micro confidential-advance product information system control
register 4: raw interrupt status (ris), offset 0x050 central location for system control raw interrupts. these are set and cleared by hardware. raw interrupt status (ris) base 0x400f .e000 of fset 0x050 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved borris reserved plllris reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:7 pll lock raw interrupt status this bit is set when the pll t ready t imer asserts. 0 ro plllris 6 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 5:2 brown-out reset raw interrupt status this bit is the raw interrupt status for any brown-out conditions. if set, a brown-out condition is currently active. this is an unregistered signal from the brown-out detection circuit. an interrupt is reported if the borim bit in the imc register is set and the borior bit in the pborctl register is cleared. 0 ro borris 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 0 69 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: interrupt mask control (imc), offset 0x054 central location for system control interrupt masks. interrupt mask control (imc) base 0x400f .e000 of fset 0x054 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved borim reserved plllim reserved ro r/w ro ro ro ro r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:7 pll lock interrupt mask this bit specifies whether a current limit detection is promoted to a controller interrupt. if set, an interrupt is generated if plllris in ris is set; otherwise, an interrupt is not generated. 0 r/w plllim 6 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 5:2 brown-out reset interrupt mask this bit specifies whether a brown-out condition is promoted to a controller interrupt. if set, an interrupt is generated if borris is set; otherwise, an interrupt is not generated. 0 r/w borim 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 0 june 14, 2007 70 luminary micro confidential-advance product information system control
register 6: masked interrupt status and clear (misc), offset 0x058 central location for system control result of ris and imc to generate an interrupt to the controller . all of the bits are r/w1c and this action also clears the corresponding raw interrupt bit in the ris register (see page 69 ). masked interrupt status and clear (misc) base 0x400f .e000 of fset 0x058 t ype r/w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved bormis reserved plllmis reserved ro r/w1c ro ro ro ro r/w1c ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:7 pll lock masked interrupt status this bit is set when the pll t ready timer asserts. the interrupt is cleared by writing a 1 to this bit. 0 r/w1c plllmis 6 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 5:2 the bormis is simply the borris anded with the mask value, borim . 0 r/w1c bormis 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 0 71 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: reset cause (resc), offset 0x05c this register is set with the reset cause after reset. the bits in this register are sticky and maintain their state across multiple reset sequences, except when an external reset is the cause, and then all the other bits in the resc register are cleared. reset cause (resc) base 0x400f .e000 of fset 0x05c t ype r/w , reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ext por bor wdt sw ldo reserved r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro t ype - - - - - - 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:6 when set, indicates the ldo circuit has lost regulation and has generated a reset event. - r/w ldo 5 when set, indicates a software reset is the cause of the reset event. - r/w sw 4 when set, indicates a watchdog reset is the cause of the reset event. - r/w wdt 3 when set, indicates a brown-out reset is the cause of the reset event. - r/w bor 2 when set, indicates a power-on reset is the cause of the reset event. - r/w por 1 when set, indicates an external reset ( rst assertion) is the cause of the reset event. - r/w ext 0 june 14, 2007 72 luminary micro confidential-advance product information system control
register 8: run-mode clock configuration (rcc), offset 0x060 this register is defined to provide source control and frequency speed. run-mode clock configuration (rcc) base 0x400f .e000 of fset 0x060 t ype r/w , reset 0x07a0.3ad1 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved usesysdiv sysdiv acg reserved ro ro ro ro ro ro r/w r/w r/w r/w r/w r/w ro ro ro ro t ype 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 moscdis ioscdis reserved oscsrc xt al reserved byp ass reserved pwrdn reserved r/w r/w ro ro r/w r/w r/w r/w r/w r/w ro r/w ro r/w ro ro t ype 1 0 0 0 1 0 1 1 0 1 0 1 1 1 1 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:28 auto clock gating this bit specifies whether the system uses the sleep-mode clock gating control (scgcn) registers and deep-sleep-mode clock gating control (dcgcn) registers if the controller enters a sleep or deep-sleep mode (respectively). if set, the scgcn or dcgcn registers are used to control the clocks distributed to the peripherals when the controller is in a sleep mode. otherwise, the run-mode clock gating control (rcgcn) registers are used when the controller enters a sleep mode. the rcgcn registers are always used to control the clocks in run mode. this allows peripherals to consume less power when the controller is in a sleep mode and the peripheral is unused. 0 r/w acg 27 73 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field system clock divisor specifies which divisor is used to generate the system clock from the pll output. the pll vco frequency is 400 mhz. frequency (byp ass=0) divisor (byp ass=1) binary v alue reserved reserved 0000-0010 50 mhz /8 001 1 40 mhz /10 0100 33.33 mhz /12 0101 28.57 mhz /14 01 10 25 mhz /16 01 1 1 22.22 mhz /18 1000 20 mhz /20 1001 18.18 mhz /22 1010 16.67 mhz /24 101 1 15.38 mhz /26 1 100 14.29 mhz /28 1 101 13.33 mhz /30 1 1 10 12.5 mhz (default) /32 1 1 1 1 when reading the run-mode clock configuration (rcc) register (see page 73 ), the sysdiv value is minsysdiv if a lower divider was requested and the pll is being used. this lower value is allowed to divide a non-pll source. 0xf r/w sysdiv 26:23 use the system clock divider as the source for the system clock. the system clock divider is forced to be used when the pll is selected as the source. 0 r/w usesysdiv 22 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1 ro reserved 21:14 pll power down this bit connects to the pll pwrdn input. the reset value of 1 powers down the pll. 1 r/w pwrdn 13 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 1 ro reserved 12 june 14, 2007 74 luminary micro confidential-advance product information system control
description reset t ype name bit/field pll bypass chooses whether the system clock is derived from the pll output or the osc source. if set, the clock that drives the system is the osc source. otherwise, the clock that drives the system is the pll output clock divided by the system divider . note: the adc must be clocked from the pll or directly from a 14-mhz to 18-mhz clock source to operate properly . while the adc works in a 14-18 mhz range, to maintain a 1 m sample/second rate, the adc must be provided a 16-mhz clock source. 1 r/w byp ass 1 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 10 this field specifies the crystal value attached to the main oscillator . the encoding for this field is provided in t able 6-3 on page 75 . 0xb r/w xt al 9:6 picks among the four input sources for the osc. the values are: input source v alue main oscillator (default) 00 internal oscillator (default) 01 internal oscillator / 4 (this is necessary if used as input to pll) 10 reserved 1 1 0x1 r/w oscsrc 5:4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 3:2 internal oscillator (iosc) disable 0: internal oscillator is enabled. 1: internal oscillator is disabled. 0 r/w ioscdis 1 main oscillator disable 0: main oscillator is enabled. 1: main oscillator is disabled (default). 1 r/w moscdis 0 t able 6-3. default crystal field v alues and pll programming crystal frequency (mhz) using the pll crystal frequency (mhz) not using the pll crystal number (xt al binary v alue) reserved 1.000 0000 reserved 1.8432 0001 reserved 2.000 0010 reserved 2.4576 001 1 3.579545 mhz 0100 3.6864 mhz 0101 4 mhz 01 10 4.096 mhz 01 1 1 75 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
crystal frequency (mhz) using the pll crystal frequency (mhz) not using the pll crystal number (xt al binary v alue) 4.9152 mhz 1000 5 mhz 1001 5.12 mhz 1010 6 mhz (reset value) 101 1 6.144 mhz 1 100 7.3728 mhz 1 101 8 mhz 1 1 10 8.192 mhz 1 1 1 1 june 14, 2007 76 luminary micro confidential-advance product information system control
register 9: xt al to pll t ranslation (pllcfg), offset 0x064 this register provides a means of translating external crystal frequencies into the appropriate pll settings. this register is initialized during the reset sequence and updated anytime that the xtal field changes in the run-mode clock configuration (rcc) register (see page 73 ). the pll frequency is calculated using the pllcfg field values, as follows: pllfreq = oscfreq * f / (r + 1) xt al to pll t ranslation (pllcfg) base 0x400f .e000 of fset 0x064 t ype ro, reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r f od ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype - - - - - - - - - - - - - - - - reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 this field specifies the value supplied to the pll s od input. - ro od 15:14 this field specifies the value supplied to the pll s f input. - ro f 13:5 this field specifies the value supplied to the pll s r input. - ro r 4:0 77 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 10: run-mode clock configuration 2 (rcc2), offset 0x070 this register overrides the rcc equivalent register fields when the usercc2 bit is set. this allows rcc2 to be used to extend the capabilities, while also providing a means to be backward-compatible to previous parts. the fields within the rcc2 register occupy the same bit positions as they do within the rcc register as lsb-justified. the sysdiv2 field is wider so that additional larger divisors are possible. this allows a lower system clock frequency for improved deep sleep power consumption. run-mode clock configuration 2 (rcc2) base 0x400f .e000 of fset 0x070 t ype r/w , reset 0x0780.2800 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved sysdiv2 reserved usercc2 ro ro ro ro ro ro ro r/w r/w r/w r/w r/w r/w ro ro r/w t ype 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved oscsrc2 reserved byp ass2 reserved pwrdn2 reserved ro ro ro ro r/w r/w r/w ro ro ro ro r/w ro r/w ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 reset description reset t ype name bit/field when set, overrides the rcc register fields. 0 r/w usercc2 31 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 30:29 system clock divisor (6-bit) specifies which divisor is used to generate the system clock from the pll output. the pll vco frequency is 400 mhz. this field is wider than the rcc register sysdiv field in order to provide additional divisor values. this permits the system clock to be run at much lower frequencies during deep sleep mode. for example, where the rcc register sysdiv encoding of 1 1 1 provides /16, the rcc2 register sysdiv2 encoding of 1 1 1 1 1 1 provides /64. 0x0f r/w sysdiv2 28:23 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 22:14 when set, powers down the pll. 1 r/w pwrdn2 13 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 12 when set, bypasses the pll for the clock source. 1 r/w byp ass2 1 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 10:7 june 14, 2007 78 luminary micro confidential-advance product information system control
description reset t ype name bit/field system clock source description v alue name main oscillator 0 mosc internal oscillator 1 iosc internal oscillator / 4 2 iosc/4 30 khz internal oscillator 3 30khz 32 khz external oscillator 7 32khz 0 r/w oscsrc2 6:4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3:0 79 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1 1: deep sleep clock configuration (dslpclkcfg), offset 0x144 this register provides configuration information for the hardware control of deep sleep mode. deep sleep clock configuration (dslpclkcfg) base 0x400f .e000 of fset 0x144 t ype r/w , reset 0x0780.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved dsdivoride reserved ro ro ro ro ro ro ro r/w r/w r/w r/w r/w r/w ro ro ro t ype 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved dsoscsrc reserved ro ro ro ro r/w r/w r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:29 6-bit system divider field to override when deep-sleep occurs with pll running. 0x0f r/w dsdivoride 28:23 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 22:7 when set, forces iosc to be clock source during deep sleep mode. description v alue name no override to the oscillator clock source is done 0 nooride use internal 12 mhz oscillator as source 1 iosc use 30 khz internal oscillator 3 30khz use 32 khz external oscillator 7 32khz 0 r/w dsoscsrc 6:4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3:0 june 14, 2007 80 luminary micro confidential-advance product information system control
register 12: device identification 1 (did1), offset 0x004 this register identifies the device family , part number , temperature range, pin count, and package type. device identification 1 (did1) base 0x400f .e000 of fset 0x004 t ype ro, reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 p ar tno f am ver ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 1 0 0 0 1 0 0 0 0 1 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 qual rohs pkg temp reserved pincount ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype - - 1 1 0 1 0 0 0 0 0 0 0 0 1 0 reset description reset t ype name bit/field this field defines the did1 register format version. the version number is numeric. the value of the ver field is encoded as follows (all other encodings are reserved): description v alue first revision of the did1 register format, indicating a stellaris lm3snnnn device. 0x1 0x1 ro ver 31:28 family this field provides the family identification of the device within the luminary micro product portfolio. the value is encoded as follows (all other encodings are reserved): description v alue stellaris family of microcontollers, that is, all devices with external part numbers starting with lm3s. 0x0 0x0 ro f am 27:24 part number this field provides the part number of the device within the family . the value is encoded as follows (all other encodings are reserved): description v alue lm3s8938 0x88 0x88 ro p ar tno 23:16 package pin count this field specifies the number of pins on the device package. the value is encoded as follows (all other encodings are reserved): description v alue 100-pin package 0x2 0x2 ro pincount 15:13 81 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 12:8 t emperature range this field specifies the temperature rating of the device. the value is encoded as follows (all other encodings are reserved): description v alue industrial temperature range (-40c to 85c) 0x1 0x1 ro temp 7:5 package t ype this field specifies the package type. the value is encoded as follows (all other encodings are reserved): description v alue lqfp package 0x1 0x1 ro pkg 4:3 rohs-compliance this bit specifies whether the device is rohs-compliant. a 1 indicates the part is rohs-compliant. 1 ro rohs 2 qualification status this field specifies the qualification status of the device. the value is encoded as follows (all other encodings are reserved): description v alue engineering sample (unqualified) 0x0 pilot production (unqualified) 0x1 fully qualified 0x2 - ro qual 1:0 june 14, 2007 82 luminary micro confidential-advance product information system control
register 13: device capabilities 0 (dc0), offset 0x008 this register is predefined by the part and can be used to verify features. device capabilities 0 (dc0) base 0x400f .e000 of fset 0x008 t ype ro, reset 0x00ff .007f 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 sramsz ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 flashsz ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field sram size indicates the size of the on-chip sram memory . description v alue 64 kb of sram 0x00ff 0x00ff ro sramsz 31:16 flash size indicates the size of the on-chip flash memory . description v alue 256 kb of flash 0x007f 0x007f ro flashsz 15:0 83 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 14: device capabilities 1 (dc1), offset 0x010 this register is predefined by the part and can be used to verify features. the pwm , saradc0 , maxadcspd , wdt , swo , swd , and jtag bits mask the rcgc0 , scgc0 , and dcgc0 registers. other bits are passed as 0. maxadcspd is clipped to the maximum value specified in dc1 . device capabilities 1 (dc1) base 0x400f .e000 of fset 0x010 t ype ro, reset 0x0101.33ff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 saradc0 reserved can0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 jt ag swd swo wdt pll tempsns hib mpu maxadcspd sysdiv ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 1 1 1 0 0 1 1 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:25 when set, indicates that can unit 0 is present. 1 ro can0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:17 when set, indicates that general sar adc 0 is present. 1 ro saradc0 16 minimum 4-bit divider value for system clock. the reset value is hardware-dependent. see the rcc register for how to change the system clock divisor using the sysdiv bit. description v alue specifies a 50-mhz cpu clock with a pll divider of 4. 0x3 0x3 ro sysdiv 15:12 this field indicates the maximum rate at which the adc samples data. description v alue 1m samples/second 0x3 0x3 ro maxadcspd 1 1:8 when set, indicates that the cortex-m3 memory protection unit (mpu) module is present. see the arm cortex-m3 t echnical reference manual for details on the mpu. 1 ro mpu 7 when set, indicates that the hibernation module is present. 1 ro hib 6 when set, indicates that the on-chip temperature sensor is present. 1 ro tempsns 5 when set, indicates that the on-chip phase locked loop (pll) is present. 1 ro pll 4 june 14, 2007 84 luminary micro confidential-advance product information system control
description reset t ype name bit/field when set, indicates that a watchdog timer is present. 1 ro wdt 3 when set, indicates that the serial wire output (swo) trace port is present. 1 ro swo 2 when set, indicates that the serial wire debugger (swd) is present. 1 ro swd 1 when set, indicates that the jt ag debugger interface is present. 1 ro jt ag 0 85 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 15: device capabilities 2 (dc2), offset 0x014 this register is predefined by the part and can be used to verify features. device capabilities 2 (dc2) base 0x400f .e000 of fset 0x014 t ype ro, reset 0x070f .5017 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 timer0 timer1 timer2 timer3 reserved comp0 comp1 comp2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 0 0 0 0 1 1 1 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 uar t0 uar t1 uar t2 reserved ssi0 reserved i2c0 reserved i2c1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 0 1 0 0 0 0 0 0 0 1 0 1 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:27 when set, indicates that analog comparator 2 is present. 1 ro comp2 26 when set, indicates that analog comparator 1 is present. 1 ro comp1 25 when set, indicates that analog comparator 0 is present. 1 ro comp0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:20 when set, indicates that general-purpose t imer module 3 is present. 1 ro timer3 19 when set, indicates that general-purpose t imer module 2 is present. 1 ro timer2 18 when set, indicates that general-purpose t imer module 1 is present. 1 ro timer1 17 when set, indicates that general-purpose t imer module 0 is present. 1 ro timer0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15 when set, indicates that i2c module 1 is present. 1 ro i2c1 14 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 13 when set, indicates that i2c module 0 is present. 1 ro i2c0 12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1:5 when set, indicates that ssi module 0 is present. 1 ro ssi0 4 june 14, 2007 86 luminary micro confidential-advance product information system control
description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3 when set, indicates that uar t module 2 is present. 1 ro uar t2 2 when set, indicates that uar t module 1 is present. 1 ro uar t1 1 when set, indicates that uar t module 0 is present. 1 ro uar t0 0 87 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 16: device capabilities 3 (dc3), offset 0x018 this register is predefined by the part and can be used to verify features. device capabilities 3 (dc3) base 0x400f .e000 of fset 0x018 t ype ro, reset 0x3fff .7fc0 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 adc0 adc1 adc2 adc3 adc4 adc5 adc6 adc7 ccp0 ccp1 ccp2 ccp3 ccp4 ccp5 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved c0minus c0plus c0o c1minus c1plus c1o c2minus c2plus c2o reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:30 when set, indicates that capture/compare/pwm pin 5 is present. 1 ro ccp5 29 when set, indicates that capture/compare/pwm pin 4 is present. 1 ro ccp4 28 when set, indicates that capture/compare/pwm pin 3 is present. 1 ro ccp3 27 when set, indicates that capture/compare/pwm pin 2 is present. 1 ro ccp2 26 when set, indicates that capture/compare/pwm pin 1 is present. 1 ro ccp1 25 when set, indicates that capture/compare/pwm pin 0 is present. 1 ro ccp0 24 when set, indicates that adc pin 7 is present. 1 ro adc7 23 when set, indicates that adc pin 6 is present. 1 ro adc6 22 when set, indicates that adc pin 5 is present. 1 ro adc5 21 when set, indicates that adc pin 4 is present. 1 ro adc4 20 when set, indicates that adc pin 3 is present. 1 ro adc3 19 when set, indicates that adc pin 2 is present. 1 ro adc2 18 when set, indicates that adc pin 1 is present. 1 ro adc1 17 when set, indicates that adc pin 0 is present. 1 ro adc0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15 when set, indicates that the analog comparator 2 output pin is present. 1 ro c2o 14 when set, indicates that the analog comparator 2 (+) input pin is present. 1 ro c2plus 13 when set, indicates that the analog comparator 2 (-) input pin is present. 1 ro c2minus 12 june 14, 2007 88 luminary micro confidential-advance product information system control
description reset t ype name bit/field when set, indicates that the analog comparator 1 output pin is present. 1 ro c1o 1 1 when set, indicates that the analog comparator 1 (+) input pin is present. 1 ro c1plus 10 when set, indicates that the analog comparator 1 (-) input pin is present. 1 ro c1minus 9 when set, indicates that the analog comparator 0 output pin is present. 1 ro c0o 8 when set, indicates that the analog comparator 0 (+) input pin is present. 1 ro c0plus 7 when set, indicates that the analog comparator 0 (-) input pin is present. 1 ro c0minus 6 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 5:0 89 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 17: device capabilities 4 (dc4), offset 0x01c this register is predefined by the part and can be used to verify features. device capabilities 4 (dc4) base 0x400f .e000 of fset 0x01c t ype ro, reset 0x5100.007f 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved e1588 reserved emac0 reserved ephy0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 1 0 0 0 1 0 1 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 gpioa gpiob gpioc gpiod gpioe gpiof gpiog reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31 when set, indicates that ethernet phy module 0 is present. 1 ro ephy0 30 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 29 when set, indicates that ethernet mac module 0 is present. 1 ro emac0 28 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 27:25 when set, indicates that that emac0 is 1588-capable. 1 ro e1588 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:7 when set, indicates that gpio port g is present. 1 ro gpiog 6 when set, indicates that gpio port f is present. 1 ro gpiof 5 when set, indicates that gpio port e is present. 1 ro gpioe 4 when set, indicates that gpio port d is present. 1 ro gpiod 3 when set, indicates that gpio port c is present. 1 ro gpioc 2 when set, indicates that gpio port b is present. 1 ro gpiob 1 when set, indicates that gpio port a is present. 1 ro gpioa 0 june 14, 2007 90 luminary micro confidential-advance product information system control
register 18: run mode clock gating control register 0 (rcgc0), offset 0x100 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc0 is the clock configuration register for running operation, scgc0 for sleep operation, and dcgc0 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. run mode clock gating control register 0 (rcgc0) base 0x400f .e000 of fset 0x100 t ype r/w , reset 0x00000040 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 saradc0 reserved can0 reserved r/w ro ro ro ro ro ro ro r/w ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved wdt reserved hib reserved maxadcspd reserved ro ro ro r/w ro ro r/w ro r/w r/w r/w r/w ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:25 this bit controls the clock gating for can unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. 0 r/w can0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:17 this bit controls the clock gating for sar adc module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, a read or write to the unit generates a bus fault. 0 r/w saradc0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15:12 91 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this field sets the rate at which the adc samples data. y ou cannot set the rate higher than the maximum rate. y ou can set the sample rate by setting the maxadcspd bit as follows: description v alue 1m samples/second 0x3 500k samples/second 0x2 250k samples/second 0x1 125k samples/second 0x0 0 r/w maxadcspd 1 1:8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7 this bit controls the clock gating for the hibernation module. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. 0 r/w hib 6 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 5:4 this bit controls the clock gating for the wdt module. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, a read or write to the unit generates a bus fault. 0 r/w wdt 3 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 2:0 june 14, 2007 92 luminary micro confidential-advance product information system control
register 19: sleep mode clock gating control register 0 (scgc0), offset 0x1 10 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc0 is the clock configuration register for running operation, scgc0 for sleep operation, and dcgc0 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. bit was changed to sleep mode clock gating control register 0 (scgc0) base 0x400f .e000 of fset 0x1 10 t ype r/w , reset 0x00000040 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 saradc0 reserved can0 reserved r/w ro ro ro ro ro ro ro r/w ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved wdt reserved hib reserved maxadcspd reserved ro ro ro r/w ro ro r/w ro r/w r/w r/w r/w ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:25 this bit controls the clock gating for can unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. 0 r/w can0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:17 this bit controls the clock gating for general sar adc module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, a read or write to the unit generates a bus fault. 0 r/w saradc0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15:12 93 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this field sets the rate at which the adc samples data. y ou cannot set the rate higher than the maximum rate.y ou can set the sample rate by setting the maxadcspd bit as follows: description v alue 1m samples/second 0x3 500k samples/second 0x2 250k samples/second 0x1 125k samples/second 0x0 0 r/w maxadcspd 1 1:8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7 this bit controls the clock gating for the hibernation module. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. 0 r/w hib 6 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 5:4 this bit controls the clock gating for the wdt module. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, a read or write to the unit generates a bus fault. 0 r/w wdt 3 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 2:0 june 14, 2007 94 luminary micro confidential-advance product information system control
register 20: deep sleep mode clock gating control register 0 (dcgc0), offset 0x120 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc0 is the clock configuration register for running operation, scgc0 for sleep operation, and dcgc0 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. bit was changed to deep sleep mode clock gating control register 0 (dcgc0) base 0x400f .e000 of fset 0x120 t ype r/w , reset 0x00000040 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 saradc0 reserved can0 reserved r/w ro ro ro ro ro ro ro r/w ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved wdt reserved hib reserved maxadcspd reserved ro ro ro r/w ro ro r/w ro r/w r/w r/w r/w ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:25 this bit controls the clock gating for can unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. 0 r/w can0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:17 this bit controls the clock gating for general sar adc module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, a read or write to the unit generates a bus fault. 0 r/w saradc0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15:12 95 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this field sets the rate at which the adc samples data. y ou cannot set the rate higher than the maximum rate. y ou can set the sample rate by setting the maxadcspd bit as follows: description v alue 1m samples/second 0x3 500k samples/second 0x2 250k samples/second 0x1 125k samples/second 0x0 0 r/w maxadcspd 1 1:8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7 this bit controls the clock gating for the hibernation module. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. 0 r/w hib 6 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 5:4 this bit controls the clock gating for the wdt module. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, a read or write to the unit generates a bus fault. 0 r/w wdt 3 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 2:0 june 14, 2007 96 luminary micro confidential-advance product information system control
register 21: run mode clock gating control register 1 (rcgc1), offset 0x104 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc1 is the clock configuration register for running operation, scgc1 for sleep operation, and dcgc1 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. run mode clock gating control register 1 (rcgc1) base 0x400f .e000 of fset 0x104 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 timer0 timer1 timer2 timer3 reserved comp0 comp1 comp2 reserved r/w r/w r/w r/w ro ro ro ro r/w r/w r/w ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 uar t0 uar t1 uar t2 reserved ssi0 reserved i2c0 reserved i2c1 reserved r/w r/w r/w ro r/w ro ro ro ro ro ro ro r/w ro r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:27 this bit controls the clock gating for analog comparator 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp2 26 this bit controls the clock gating for analog comparator 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp1 25 this bit controls the clock gating for analog comparator 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:20 this bit controls the clock gating for general-purpose t imer module 3. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer3 19 97 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this bit controls the clock gating for general-purpose t imer module 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer2 18 this bit controls the clock gating for general-purpose t imer module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer1 17 this bit controls the clock gating for general-purpose t imer module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15 this bit controls the clock gating for i2c module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w i2c1 14 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 13 this bit controls the clock gating for i2c module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w i2c0 12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1:5 this bit controls the clock gating for ssi module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w ssi0 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3 this bit controls the clock gating for uar t module 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t2 2 this bit controls the clock gating for uar t module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t1 1 this bit controls the clock gating for uar t module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t0 0 june 14, 2007 98 luminary micro confidential-advance product information system control
register 22: sleep mode clock gating control register 1 (scgc1), offset 0x1 14 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc1 is the clock configuration register for running operation, scgc1 for sleep operation, and dcgc1 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. sleep mode clock gating control register 1 (scgc1) base 0x400f .e000 of fset 0x1 14 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 timer0 timer1 timer2 timer3 reserved comp0 comp1 comp2 reserved r/w r/w r/w r/w ro ro ro ro r/w r/w r/w ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 uar t0 uar t1 uar t2 reserved ssi0 reserved i2c0 reserved i2c1 reserved r/w r/w r/w ro r/w ro ro ro ro ro ro ro r/w ro r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:27 this bit controls the clock gating for analog comparator 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp2 26 this bit controls the clock gating for analog comparator 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp1 25 this bit controls the clock gating for analog comparator 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:20 this bit controls the clock gating for general-purpose t imer module 3. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer3 19 99 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this bit controls the clock gating for general-purpose t imer module 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer2 18 this bit controls the clock gating for general-purpose t imer module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer1 17 this bit controls the clock gating for general-purpose t imer module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15 this bit controls the clock gating for i2c module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w i2c1 14 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 13 this bit controls the clock gating for i2c module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w i2c0 12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1:5 this bit controls the clock gating for ssi module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w ssi0 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3 this bit controls the clock gating for uar t module 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t2 2 this bit controls the clock gating for uar t module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t1 1 this bit controls the clock gating for uar t module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t0 0 june 14, 2007 100 luminary micro confidential-advance product information system control
register 23: deep sleep mode clock gating control register 1 (dcgc1), offset 0x124 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc1 is the clock configuration register for running operation, scgc1 for sleep operation, and dcgc1 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. deep sleep mode clock gating control register 1 (dcgc1) base 0x400f .e000 of fset 0x124 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 timer0 timer1 timer2 timer3 reserved comp0 comp1 comp2 reserved r/w r/w r/w r/w ro ro ro ro r/w r/w r/w ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 uar t0 uar t1 uar t2 reserved ssi0 reserved i2c0 reserved i2c1 reserved r/w r/w r/w ro r/w ro ro ro ro ro ro ro r/w ro r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:27 this bit controls the clock gating for analog comparator 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp2 26 this bit controls the clock gating for analog comparator 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp1 25 this bit controls the clock gating for analog comparator 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w comp0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:20 this bit controls the clock gating for general-purpose t imer module 3. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer3 19 101 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this bit controls the clock gating for general-purpose t imer module 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer2 18 this bit controls the clock gating for general-purpose t imer module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer1 17 this bit controls the clock gating for general-purpose t imer module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w timer0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15 this bit controls the clock gating for i2c module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w i2c1 14 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 13 this bit controls the clock gating for i2c module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w i2c0 12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1:5 this bit controls the clock gating for ssi module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w ssi0 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3 this bit controls the clock gating for uar t module 2. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t2 2 this bit controls the clock gating for uar t module 1. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t1 1 this bit controls the clock gating for uar t module 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w uar t0 0 june 14, 2007 102 luminary micro confidential-advance product information system control
register 24: run mode clock gating control register 2 (rcgc2), offset 0x108 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc2 is the clock configuration register for running operation, scgc2 for sleep operation, and dcgc2 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. run mode clock gating control register 2 (rcgc2) base 0x400f .e000 of fset 0x108 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved emac0 reserved ephy0 reserved ro ro ro ro ro ro ro ro ro ro ro ro r/w ro r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 gpioa gpiob gpioc gpiod gpioe gpiof gpiog reserved r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31 this bit controls the clock gating for ethernet phy unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w ephy0 30 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 29 this bit controls the clock gating for ethernet mac unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w emac0 28 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 27:7 this bit controls the clock gating for port g. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiog 6 this bit controls the clock gating for port f . if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiof 5 103 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this bit controls the clock gating for port e. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioe 4 this bit controls the clock gating for port d. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiod 3 this bit controls the clock gating for port c. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioc 2 this bit controls the clock gating for port b. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiob 1 this bit controls the clock gating for port a. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioa 0 june 14, 2007 104 luminary micro confidential-advance product information system control
register 25: sleep mode clock gating control register 2 (scgc2), offset 0x1 18 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc2 is the clock configuration register for running operation, scgc2 for sleep operation, and dcgc2 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. sleep mode clock gating control register 2 (scgc2) base 0x400f .e000 of fset 0x1 18 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved emac0 reserved ephy0 reserved ro ro ro ro ro ro ro ro ro ro ro ro r/w ro r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 gpioa gpiob gpioc gpiod gpioe gpiof gpiog reserved r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31 this bit controls the clock gating for ethernet phy unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w ephy0 30 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 29 this bit controls the clock gating for ethernet mac unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w emac0 28 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 27:7 this bit controls the clock gating for port g. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiog 6 105 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this bit controls the clock gating for port f . if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiof 5 this bit controls the clock gating for port e. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioe 4 this bit controls the clock gating for port d. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiod 3 this bit controls the clock gating for port c. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioc 2 this bit controls the clock gating for port b. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiob 1 this bit controls the clock gating for port a. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioa 0 june 14, 2007 106 luminary micro confidential-advance product information system control
register 26: deep sleep mode clock gating control register 2 (dcgc2), offset 0x128 this register controls the clock gating logic. each bit controls a clock enable for a given interface, function, or unit. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled (saving power). if the unit is unclocked, reads or writes to the unit will generate a bus fault. the reset state of these bits is 0 (unclocked) unless otherwise noted, so that all functional units are disabled. it is the responsibility of software to enable the ports necessary for the application. note that these registers may contain more bits than there are interfaces, functions, or units to control. this is to assure reasonable code compatibility with other family and future parts. rcgc2 is the clock configuration register for running operation, scgc2 for sleep operation, and dcgc2 for deep-sleep operation. setting the acg bit in the run-mode clock configuration (rcc) register specifies that the system uses sleep modes. deep sleep mode clock gating control register 2 (dcgc2) base 0x400f .e000 of fset 0x128 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved emac0 reserved ephy0 reserved ro ro ro ro ro ro ro ro ro ro ro ro r/w ro r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 gpioa gpiob gpioc gpiod gpioe gpiof gpiog reserved r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31 this bit controls the clock gating for ethernet phy unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w ephy0 30 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 29 this bit controls the clock gating for ethernet mac unit 0. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w emac0 28 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 27:7 this bit controls the clock gating for port g. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiog 6 107 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field this bit controls the clock gating for port f . if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiof 5 this bit controls the clock gating for port e. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioe 4 this bit controls the clock gating for port d. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiod 3 this bit controls the clock gating for port c. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioc 2 this bit controls the clock gating for port b. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpiob 1 this bit controls the clock gating for port a. if set, the unit receives a clock and functions. otherwise, the unit is unclocked and disabled. if the unit is unclocked, reads or writes to the unit will generate a bus fault. 0 r/w gpioa 0 june 14, 2007 108 luminary micro confidential-advance product information system control
register 27: software reset control 0 (srcr0), offset 0x040 w rites to this register are masked by the bits in the device capabilities 1 (dc1) register . software reset control 0 (srcr0) base 0x400f .e000 of fset 0x040 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 saradc0 reserved can0 reserved r/w ro ro ro ro ro ro ro r/w ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved wdt reserved hib reserved ro ro ro r/w ro ro r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:25 reset control for can unit 0. 0 r/w can0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:17 reset control for sar adc module 0. 0 r/w saradc0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15:7 reset control for the hibernation module. 0 r/w hib 6 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 5:4 reset control for w atchdog unit. 0 r/w wdt 3 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 2:0 109 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 28: software reset control 1 (srcr1), offset 0x044 w rites to this register are masked by the bits in the device capabilities 2 (dc2) register . software reset control 1 (srcr1) base 0x400f .e000 of fset 0x044 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 timer0 timer1 timer2 timer3 reserved comp0 comp1 comp2 reserved r/w r/w r/w r/w ro ro ro ro r/w r/w r/w ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 uar t0 uar t1 uar t2 reserved ssi0 reserved i2c0 reserved i2c1 reserved r/w r/w r/w ro r/w ro ro ro ro ro ro ro r/w ro r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:27 reset control for analog comparator 2. 0 r/w comp2 26 reset control for analog comparator 1. 0 r/w comp1 25 reset control for analog comparator 0. 0 r/w comp0 24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23:20 reset control for general-purpose t imer module 3. 0 r/w timer3 19 reset control for general-purpose t imer module 2. 0 r/w timer2 18 reset control for general-purpose t imer module 1. 0 r/w timer1 17 reset control for general-purpose t imer module 0. 0 r/w timer0 16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15 reset control for i2c unit 1. 0 r/w i2c1 14 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 13 reset control for i2c unit 0. 0 r/w i2c0 12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1:5 reset control for ssi unit 0. 0 r/w ssi0 4 june 14, 2007 1 10 luminary micro confidential-advance product information system control
description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3 reset control for uar t unit 2. 0 r/w uar t2 2 reset control for uar t unit 1. 0 r/w uar t1 1 reset control for uar t unit 0. 0 r/w uar t0 0 1 1 1 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 29: software reset control 2 (srcr2), offset 0x048 w rites to this register are masked by the bits in the device capabilities 4 (dc4) register . software reset control 2 (srcr2) base 0x400f .e000 of fset 0x048 t ype r/w , reset 0x00000000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved emac0 reserved ephy0 reserved ro ro ro ro ro ro ro ro ro ro ro ro r/w ro r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 gpioa gpiob gpioc gpiod gpioe gpiof gpiog reserved r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31 reset control for ethernet phy unit 0. 0 r/w ephy0 30 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 29 reset control for ethernet mac unit 0. 0 r/w emac0 28 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 27:7 reset control for gpio port g. 0 r/w gpiog 6 reset control for gpio port f . 0 r/w gpiof 5 reset control for gpio port e. 0 r/w gpioe 4 reset control for gpio port d. 0 r/w gpiod 3 reset control for gpio port c. 0 r/w gpioc 2 reset control for gpio port b. 0 r/w gpiob 1 reset control for gpio port a. 0 r/w gpioa 0 june 14, 2007 1 12 luminary micro confidential-advance product information system control
7 hibernation module hib the hibernation module manages removal and restoration of power to the rest of the microcontroller to provide a means for reducing power consumption. when the processor and peripherals are idle, power can be completely removed with only the hibernation module remaining powered. power can be restored based on an external signal, or at a certain time using the built-in real-time clock (r tc). the hibernation module can be independently supplied from a battery or an auxillary power supply . the hibernation module has the following features: power-switching logic to discrete external regulator dedicated pin for waking from an external signal low-battery detection, signalling, and interrupt generation 32-bit real-time counter (r tc) t wo 32-bit r tc match registers for timed wake-up and interrupt generation clock source from a 32.768-khz external oscillator or a 4.194304-mhz crystal r tc trim predivider for making fine adjustments to the clock rate 64 32-bit words of non-volatile memory programmable interrupts for r tc match, external wake, and low battery events 1 13 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
7.1 block diagram figure 7-1. hibernation module block diagram 7.2 functional description the hibernation module controls the power to the processor with an enable signal ( hib ) that signals an external voltage regulator to turn of f. the hibernation module itself is powered from a separate supply such as a battery or auxillary supply . it also has a separate clock source to maintain a real-time clock (r tc). once in hibernation, the module signals an external voltage regulator to turn back on the power when an external pin ( wake ) is asserted, or when the internal r tc reaches a certain value. the hibernation module can also detect when the battery voltage is low , and optionally prevent hibernation when this occurs. power-up from a power cut to code execution is defined as the regulator turn-on time (specifed at 250 s maximum) plus the normal chip por (see figure 22-12 on page 524 ). 7.2.1 register access t iming because the hibernation module has an independent clocking domain, certain registers must be written only with a timing gap between accesses. the delay time is t hib_reg_write , therefore software must guarantee that a delay of t hib_reg_write is inserted between back-to-back writes to certain hibernation registers, or between a write followed by a read to those same registers. there is no restriction on timing for back-to-back reads from the hibernation module. refer to register descriptions on page 118 for details about which registers are subject to this timing restriction. june 14, 2007 1 14 luminary micro confidential-advance product information hibernation module hibim hibris hibmis hibic hibr tct pre-divider /128 xosc0 xosc1 hibctl.clk32en hibctl.clksel hibr tcc hibr tcld hibr tcm0 hibr tcm1 r tc interrupts power sequence logic ma tch0/1 w ake interrupts to cpu low battery detect lowba t vdd vba t hib hibctl.lowba ten hibctl.pwrcut hibctl.extwen hibctl.r tcwen hibctl.v abor t non-v olatile memory hibda t a
7.2.2 clock source the hibernation module must be clocked by an external source, even if the r tc feature will not be used. an external oscillator or crystal can be used for this purpose. t o use a crystal, a 4.194304-mhz crystal is connected to the xosc0 and xosc1 pins. this clock signal will be divided by 128 internally to produce the 32.768-khz clock reference. t o use a more precise clock source, a 32.768-khz oscillator can be connected to the xosc0 pin. the clock source is enabled by setting the clk32en bit of the hibctl register . the type of clock source is selected by setting the clksel bit to 0 for a 4.194304-mhz clock source, and to 1 for a 32.768-khz clock source. if the bit is set to 0, the input clock is divided by 128, resulting in a 32.768-khz clock source. if a crystal is used for the clock source, the software must leave a delay of t xosc_settle after setting the clk32en bit and before any other accesses to the hibernation module registers. the delay allows the crystal to power up and stabilize. if an oscillator is used for the clock source, no delay is needed. 7.2.3 battery management the hibernation module can be independently powered by a battery or an auxiliary power source. the module can monitor the voltage level of the battery and detect when the voltage becomes too low . when this happens, an interrupt can be generated. the module can also be configured so that it will not go into hibernate mode if the battery voltage is too low . note that the hibernation module draws power from whichever source ( vbat or vdd ) has the higher voltage. therefore, it is important to design the circuit to ensure that vdd is higher that vbat under nominal conditions or else the hibernation module draws power from the battery even when vdd is available. the hibernation module can be configured to detect a low battery condition by setting the lowbaten bit of the hibctl register . in this configuration, the lowbat bit of the hibris register will be set when the battery level is low . if the vabort bit is also set, then the module is prevented from entering hibernation mode when a low battery is detected. the module can also be configured to generate an interrupt for the low-battery condition (see interrupts and status on page 116 ). 7.2.4 real-t ime clock the hibernation module includes a 32-bit counter that increments once per second with a proper clock source and configuration (see clock source on page 115 ). the 32.768-khz clock signal is fed into a trim predivider which counts down from a nominal value of 0x7fff to achieve a once per second clock rate for the r tc. the trim predivider register can be adjusted up or down to compensate for inaccuracies in the clock source. the trim predivider should be adjusted up from 0x7fff in order to slow down the r tc rate, and down from 0x7fff in order to speed up the r tc rate. the hibernation module includes two 32-bit match registers that are compared to the value of the r tc counter . the match registers can be used to wake the processor from hibernation mode, or to generate an interrupt to the processor if it is not in hibernation. the r tc must be enabled with the rtcen bit of the hibctl register . the value of the r tc can be set at any time by writing to the hibrtcld register . the trim predivider can be adjusted by reading and writing the hibrtct register . the predivider is updated once every 64 seconds from this register . the two match registers can be set by writing to the hibrtcm0 and hibrtcm1 registers. the r tc can be configured to generate interrupts by using the interrupt registers (see interrupts and status on page 116 ). 1 15 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
7.2.5 non-v olatile memory the hibernation module contains 64 32-bit words of memory which are retained during hibernation. this memory is powered from the battery or auxillary power supply during hibernation. the processor software can save state information in this memory prior to hibernation, and can then recover the state upon waking. the non-volatile memory can be accessed through the hibda t a registers. 7.2.6 power control the hibernation module controls power to the processor through the use of the hib pin, which is intended to be connected to the enable signal of the external regulator(s) providing 3.3 v and/or 2.5 v to the microcontroller . when the hib signal is asserted by the hibernation module, the external regulator is turned of f and no longer powers the microcontroller . the hibernation module remains powered from the vbat supply , which could be a battery or an auxillary power source. hibernation mode is initiated by the microcontroller setting the hibreq bit of the hibctl register . prior to doing this, a wake-up condition must be configured, either from the external wake pin, or by using an r tc match. the hibernation module is configured to wake from the external wake pin by setting the pinwen bit of the hibctl register . it is configured to wake from r tc match by setting the rtcwen bit. either one or both of these bits can be set prior to going into hibernation. when the hibernation module wakes, the microcontroller will see a normal power-on reset. it can detect that the power-on was due to a wake from hibernation by examining the raw interrupt status register (see interrupts and status on page 116 ) and by looking for state data in the non-volatile memory (see non-v olatile memory on page 116 ). 7.2.7 interrupts and status the hibernation module can generate interrupts when the following conditions occur: assertion of wake pin r tc match low battery detected all of the interrupts are ored together before being sent to the interrupt controller , so the hibernate module can only generate a single interrupt request to the controller at any given time. the software interrupt handler can service multiple interrupt events by reading the hibmis register . software can also read the status of the hibernation module at any time by reading the hibris register which shows all of the pending events. this register can be used at power-on to see if a wake condition is pending, which indicates to the software that a hibernation wake occurred. the events that can trigger an interrupt are configured by setting the appropriate bits in the hibim register . pending interrupts can be cleared by writing the corresponding bit in the hibic register . 7.3 initialization and configuration the hibernation module can be configured in several dif ferent combinations. the following sections show the recommended programming sequence for various scenarios. the examples below assume that a 32.768-khz oscillator is used, and thus always show bit 2 ( clksel ) of the hibctl register set to 1. if a 4.194304-mhz crystal is used instead, then the clksel bit remains cleared. because the hibernation module runs at 32 khz and is asynchronous to the rest of the system, software must allow a delay of t hib_reg_write after writes to certain registers (see register access june 14, 2007 1 16 luminary micro confidential-advance product information hibernation module
t iming on page 114 ). the registers that require a delay are denoted with a footnote in t able 7-1 on page 118 . 7.3.1 initialization the clock source must be enabled first, even if the r tc will not be used. if a 4.194304-mhz crystal is used, perform the following steps: 1. w rite 0x40 to the hibctl register at of fset 0x10 to enable the crystal and select the divide-by-128 input path. 2. w ait for a time of t xosc_settle for the crystal to power up and stabilize before performing any other operations with the hibernation module. if a 32.678-khz oscillator is used, then perform the following steps: 1. w rite 0x44 to the hibctl register at of fset 0x10 to enable the oscillator input. 2. no delay is necessary . the above is only necessary when the entire system is initialized for the first time. if the processor is powered due to a wake from hibernation, then the hibernation module has already been powered up and the above steps are not necessary . the software can detect that the hibernation module and clock are already powered by examining the clk32en bit of the hibctl register . 7.3.2 rtc match functionality (no hibernation) the following steps are needed to use the r tc match functionality of the hibernation module: 1. w rite the required r tc match value to one of the hibrtcmn registers at of fset 0x004 or 0x008. 2. w rite the required r tc load value to the hibrtcld register at of fset 0x00c. 3. set the required r tc match interrupt mask in the rtcalt0 and rtcalt1 bits (bits 1:0) in the hibim register at of fset 0x014. 4. w rite 0x0000.0041 to the hibctl register at of fset 0x010 to enable the r tc to begin counting. 7.3.3 rtc match/w ake-up from hibernation the following steps are needed to use the r tc match and wake-up functionality of the hibernation module: 1. w rite the required r tc match value to the rtcmn registers at of fset 0x004 or 0x008. 2. w rite the required r tc load value to the hibrtcld register at of fset 0x00c. 3. w rite any data to be retained during power cut to the hibda t a register at of fsets 0x030-0x130. 4. set the r tc match w ake-up and start the hibernation sequence by writing 0x0000.004f to the hibctl register at of fset 0x010. 7.3.4 external w ake-up from hibernation the following steps are needed to use the hibernation module with the external wake pin as the wake-up source for the microcontroller: 1 17 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
1. w rite any data to be retained during power cut to the hibda t a register at of fsets 0x030-0x130. 2. enable the external wake and start the hibernation sequence by writing 0x0000.0056 to the hibctl register at of fset 0x010. 7.3.5 rtc/external w ake-up from hibernation 1. w rite the required r tc match value to the rtcmn registers at of fset 0x004 or 0x008. 2. w rite the required r tc load value to the hibrtcld register at of fset 0x00c. 3. w rite any data to be retained during power cut to the hibda t a register at of fsets 0x030-0x130. 4. set the r tc match/external w ake-up and start the hibernation sequence by writing 0x0000.005f to the hibctl register at of fset 0x010. 7.4 register map note: hibrtcc , hibrtcm0 , hibrtcm1 , hibrtcld , hibrtct , and hibda t a are internal bapi module registers on the vbapi voltage domain and the 32-khz clock domain. t able 7-1. hibernation module register map see page description reset t ype name offset 119 hibernation r tc counter 0x0000.0000 ro hibr tcc 0x000 120 hibernation r tc match 0 0xffff .ffff r/w hibr tcm0 0x004 121 hibernation r tc match 1 0xffff .ffff r/w hibr tcm1 0x008 122 hibernation r tc load 0xffff .ffff r/w hibr tcld 0x00c 123 hibernation control 0x0000.0000 r/w hibctl 0x010 125 hibernation interrupt mask 0x0000.0000 r/w hibim 0x014 126 hibernation raw interrupt status 0x0000.0000 ro hibris 0x018 127 hibernation masked interrupt status 0x0000.0000 ro hibmis 0x01c 128 hibernation interrupt clear 0x0000.0000 w1c hibic 0x020 129 hibernation r tc t rim 0x0000.0000 r/w hibr tct 0x024 130 hibernation data 0x0000.0000 r/w hibda t a 0x030- 0x12c 7.5 register descriptions all addresses given are relative to the hibernation module base address at 0x400f .c000. june 14, 2007 1 18 luminary micro confidential-advance product information hibernation module
register 1: hibernation rtc counter (hibrtcc), offset 0x000 this register is the current 32-bit value of the r tc counter . hibernation r tc counter (hibr tcc) of fset 0x000 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 r tcc ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcc ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field r tc counter a read returns the 32-bit counter value. this register is read-only . t o change the value, use the hibrtcld register . 0x0000.0000 ro r tcc 31:0 1 19 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 2: hibernation rtc match 0 (hibrtcm0), offset 0x004 this register is the 32-bit match 0 register for the r tc counter . hibernation r tc match 0 (hibr tcm0) of fset 0x004 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 r tcm0 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcm0 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field r tc match 0 a write loads the value into the r tc match register . a read returns the current match value. 0xffff .ffff r/w r tcm0 31:0 june 14, 2007 120 luminary micro confidential-advance product information hibernation module
register 3: hibernation rtc match 1 (hibrtcm1), offset 0x008 this register is the 32-bit match 1 register for the r tc counter . hibernation r tc match 1 (hibr tcm1) of fset 0x008 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 r tcm1 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcm1 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field r tc match 1 a write loads the value into the r tc match register . a read returns the current match value. 0xffff .ffff r/w r tcm1 31:0 121 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 4: hibernation rtc load (hibrtcld), offset 0x00c this register is the 32-bit value loaded into the r tc counter . hibernation r tc load (hibr tcld) of fset 0x00c t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 r tcld r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcld r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field r tc load a writes load the current value into the r tc counter (r tcc). a read returns the 32-bit load value. 0xffff .ffff r/w r tcld 31:0 june 14, 2007 122 luminary micro confidential-advance product information hibernation module
register 5: hibernation control (hibctl), offset 0x010 this register is the control register for the hibernation module. hibernation control (hibctl) of fset 0x010 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcen hibreq clksel r tcwen pinwen lowba ten clk32en v abor t reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x00 ro reserved 31:8 power cut abort enable 0: power cut occurs during a low-battery alert 1: power cut is aborted 0 r/w v abor t 7 32-khz oscillator enable 0: disabled 1: enabled this bit must be enabled to use the hibernation module. if a crystal is used, then software should wait 20 ms after setting this bit to allow the crystal to power up and stabilize. 0 r/w clk32en 6 low ba t monitoring enable 0: disabled 1: enabled when set, low battery voltage detection is enabled. 0 r/w lowba ten 5 external wake pin enable 0: disabled 1: enabled when set, an external event on the wake pin will re-power the device. 0 r/w pinwen 4 r tc w ake-up enable 0: disabled 1: enabled when set, an r tc match event (r tc0 or r tc1) will re-power the device based on the r tc counter value matching the corresponding match register 0 or 1. 0 r/w r tcwen 3 123 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field hibernation module clock select 0: use divide by 128 output. use this value for a 4-mhz crystal. 1: use raw output. use this value for a 32-khz oscillator . 0 r/w clksel 2 hibernation request 0: disabled 1: hibernation initiated after a wake-up event, this bit is cleared by hardware. 0 r/w hibreq 1 r tc t imer enable 0: disabled 1: enabled 0 r/w r tcen 0 june 14, 2007 124 luminary micro confidential-advance product information hibernation module
register 6: hibernation interrupt mask (hibim), offset 0x014 this register is the interrupt mask register for the hibernation module interrupt sources. hibernation interrupt mask (hibim) of fset 0x014 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcal t0 r tcal t1 lowba t extw reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x000.0000 ro reserved 31:4 external w ake-up interrupt mask 0: masked 1: unmasked 0 r/w extw 3 low battery v oltage interrupt mask 0: masked 1: unmasked 0 r/w lowba t 2 r tc alert1 interrupt mask 0: masked 1: unmasked 0 r/w r tcal t1 1 r tc alert0 interrupt mask 0: masked 1: unmasked 0 r/w r tcal t0 0 125 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: hibernation raw interrupt status (hibris), offset 0x018 this register is the raw interrupt status for the hibernation module interrupt sources. hibernation raw interrupt status (hibris) of fset 0x018 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcal t0 r tcal t1 lowba t extw reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x000.0000 ro reserved 31:4 external w ake-up raw interrupt status 0 ro extw 3 low battery v oltage raw interrupt status 0 ro lowba t 2 r tc alert1 raw interrupt status 0 ro r tcal t1 1 r tc alert0 raw interrupt status 0 ro r tcal t0 0 june 14, 2007 126 luminary micro confidential-advance product information hibernation module
register 8: hibernation masked interrupt status (hibmis), offset 0x01c this register is the masked interrupt status for the hibernation module interrupt sources. hibernation masked interrupt status (hibmis) of fset 0x01c t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcal t0 r tcal t1 lowba t extw reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x000.0000 ro reserved 31:4 external w ake-up masked interrupt status 0 ro extw 3 low battery v oltage masked interrupt status 0 ro lowba t 2 r tc alert1 masked interrupt status 0 ro r tcal t1 1 r tc alert0 masked interrupt status 0 ro r tcal t0 0 127 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 9: hibernation interrupt clear (hibic), offset 0x020 this register is the interrupt write-one-to-clear register for the hibernation module interrupt sources. hibernation interrupt clear (hibic) of fset 0x020 t ype w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r tcal t0 r tcal t1 lowba t extw reserved r/w1c r/w1c r/w1c r/w1c ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x000.0000 ro reserved 31:4 external w ake-up masked interrupt clear reads return an indeterminate value. 0 r/w1c extw 3 low battery v oltage masked interrupt clear reads return an indeterminate value. 0 r/w1c lowba t 2 r tc alert1 masked interrupt clear reads return an indeterminate value. 0 r/w1c r tcal t1 1 r tc alert0 masked interrupt clear reads, return an indeterminate value. 0 r/w1c r tcal t0 0 june 14, 2007 128 luminary micro confidential-advance product information hibernation module
register 10: hibernation rtc t rim (hibrtct), offset 0x024 this register contains the value that is used to trim the r tc clock predivider . it represents the computed underflow value that is used during the trim cycle. it is represented as 0x7fff n clock cycles. hibernation r tc t rim (hibr tct) of fset 0x024 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 trim r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 r tc t rim v alue this value is loaded into the r tc predivider every 64 seconds. it is used to adjust the r tc rate to account for drift and inaccuracy in the clock source. the compensation is made by software by adjusting the default value of 0x7fff up or down. 0x7fff r/w trim 15:0 129 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1 1: hibernation data (hibda t a), offset 0x030-0x12c this address space is implemented as a 64x32-bit memory (256 bytes). it can be loaded by the system processor in order to store any non-volatile state data and will not lose power during a power cut operation. hibernation data (hibda t a) of fset 0x030-0x12c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 r td r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r td r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field hibernation module nv registers[63:0] 0x0000.0000 r/w r td 31:0 june 14, 2007 130 luminary micro confidential-advance product information hibernation module
8 internal memory flash the lm3s8938 microcontroller comes with 64 kb of bit-banded sram and 256 kb of flash memory . the flash controller provides a user-friendly interface, making flash programming a simple task. flash protection can be applied to the flash memory on a 2-kb block basis. 8.1 block diagram figure 8-1. flash block diagram 8.2 functional description this section describes the functionality of both the flash and sram memories. 8.2.1 sram memory the internal sram of the stellaris ? devices is located at address 0x2000.0000 of the device memory map. t o reduce the number of time consuming read-modify-write (rmw) operations, arm has introduced bit-banding technology in the cortex-m3 processor . with a bit-band-enabled processor , certain regions in the memory map (sram and peripheral space) can use address aliases to access individual bits in a single, atomic operation. 131 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller flash control fma fcmisc fcim fcris fmc fmd flash t iming usecrl flash protection fmpren fmppen flash array sram array bridge cortex-m3 icode dcode system bus apb user registers user_reg0 user_reg1 user_dbg
the bit-band alias is calculated by using the formula: bit-band alias = bit-band base + (byte offset * 32) + (bit number * 4) for example, if bit 3 at address 0x2000.1000 is to be modified, the bit-band alias is calculated as: 0x2200.0000 + (0x1000 * 32) + (3 * 4) = 0x2202.000c with the alias address calculated, an instruction performing a read/write to address 0x2202.000c allows direct access to only bit 3 of the byte at address 0x2000.1000. for details about bit-banding, please refer to chapter 4, memory map in the arm? cortex?-m3 t echnical reference manual . 8.2.2 flash memory the flash is organized as a set of 1-kb blocks that can be individually erased. erasing a block causes the entire contents of the block to be reset to all 1s. an individual 32-bit word can be programmed to change bits that are currently 1 to a 0. these blocks are paired into a set of 2-kb blocks that can be individually protected. the protection allows blocks to be marked as read-only or execute-only , providing dif ferent levels of code protection. read-only blocks cannot be erased or programmed, protecting the contents of those blocks from being modified. execute-only blocks cannot be erased or programmed, and can only be read by the controller instruction fetch mechanism, protecting the contents of those blocks from being read by either the controller or by a debugger . 8.2.2.1 flash memory t iming the timing for the flash is automatically handled by the flash controller . however , in order to do so, it must know the clock rate of the system in order to time its internal signals properly . the number of clock cycles per microsecond must be provided to the flash controller for it to accomplish this timing. it is software's responsibility to keep the flash controller updated with this information via the usec reload (usecrl) register . on reset, the usecrl register is loaded with a value that configures the flash timing so that it works with the maximum clock rate of the part. if software changes the system operating frequency , the new operating frequency minus 1 (in mhz) must be loaded into usecrl before any flash modifications are attempted. for example, if the device is operating at a speed of 20 mhz, a value of 0x13 (20-1) must be written to the usecrl register . 8.2.2.2 flash memory protection the user is provided two forms of flash protection per 2-kb flash blocks infour pairs of 32-bit wide registers. the protection policy for each form is controlled by individual bits (per policy per block) in the fmppen and fmpren registers. flash memory protection program enable (fmppen) : if set, the block may be programmed (written) or erased. if cleared, the block may not be changed. flash memory protection read enable (fmpren) : if set, the block may be executed or read by software or debuggers. if cleared, the block may only be executed. the contents of the memory block are prohibited from being accessed as data and traversing the dcode bus. the policies may be combined as shown in t able 8-1 on page 133 . june 14, 2007 132 luminary micro confidential-advance product information internal memory
t able 8-1. flash protection policy combinations protection fmpren fmppen execute-only protection. the block may only be executed and may not be written or erased. this mode is used to protect code. 0 0 the block may be written, erased or executed, but not read. this combination is unlikely to be used. 0 1 read-only protection. the block may be read or executed but may not be written or erased. this mode is used to lock the block from further modification while allowing any read or execute access. 1 0 no protection. the block may be written, erased, executed or read. 1 1 an access that attempts to program or erase a pe-protected block is prohibited. a controller interrupt may be optionally generated (by setting the amask bit in the fim register) to alert software developers of poorly behaving software during the development and debug phases. an access that attempts to read an re-protected block is prohibited. such accesses return data filled with all 0s. a controller interrupt may be optionally generated to alert software developers of poorly behaving software during the development and debug phases. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this implements a policy of open access and programmability . the register bits may be changed by writing the specific register bit. the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. details on programming these bits are discussed in nonvolatile register programming on page 134 . 8.3 flash memory initialization and configuration 8.3.1 flash programming the stellaris ? devices provide a user-friendly interface for flash programming. all erase/program operations are handled via three registers: fma , fmd , and fmc . 8.3.1.1 t o program a 32-bit word: 1. w rite source data to the fmd register . 2. w rite the target address to the fma register . 3. w rite the flash write key and the write bit (a value of 0xa442.0001) to the fmc register . 4. poll the fmc register until the write bit is cleared. 8.3.1.2 t o perform an erase of a 1-kb page: 1. w rite the page address to the fma register . 2. w rite the flash write key and the erase bit (a value of 0xa442.0002) to the fmc register . 3. poll the fmc register until the erase bit is cleared. 8.3.1.3 t o perform a mass erase of the flash: 1. w rite the flash write key and the merase bit (a value of 0xa442.0004) to the fmc register . 2. poll the fmc register until the merase bit is cleared. 133 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
8.3.2 nonvolatile register programming this section discusses how to update registers that are resident within the flash memory itself. these registers exist in a separate space from the main flash array and are not af fected by an erase or mass erase operation. these nonvolatile registers are updated by using the comt bit in the fmc register to activate a write operation. for the user_dbg register , the data to be written must be loaded into the fmd register before it is "committed". all other registers are r/w and can have their operation tried before committing them to nonvolatile memory . important: these register can only have bits changed from 1 to 0 by the user and there is no mechanism for the user to erase them back to a 1 value. in addition, the user_reg0 , user_reg1 , and user_dbg use bit 31 ( notwritten ) of their respective registers to indicate that they are available for user write. these three registers can only be written once whereas the flash protection registers may be written multiple times. t able 8-2 on page 134 provides the fma address required for commitment of each of the registers and the source of the data to be written when the comt bit of the fmc register is written with a value of 0xa442.0008. after writing the comt bit, the user may poll the fmc register to wait for the commit operation to complete. t able 8-2. flash resident registers a data source fma v alue register to be committed fmpre0 0x0000.0000 fmpre0 fmpre1 0x0000.0002 fmpre1 fmpre2 0x0000.0004 fmpre2 fmpre3 0x0000.0008 fmpre3 fmppe0 0x0000.0001 fmppe0 fmppe1 0x0000.0003 fmppe1 fmppe2 0x0000.0005 fmppe2 fmppe3 0x0000.0007 fmppe3 user_reg0 0x8000.0000 user_reg0 user_reg1 0x8000.0001 user_reg1 fmd 0x7510.0000 user_dbg a. which fmpren and fmppen registers are available depend on the flash size of your particular stellaris ? device. 8.4 register map t able 8-3 on page 134 lists the flash memory and control registers. the of fset listed is a hexadecimal increment to the register's address. the fma , fmd , fmc , fcris , fcim , and fcmisc registers are relative to the flash control base address of 0x400f .d000. the fmpren , fmppen , usecrl , user_dbg , and user_regn registers are relative to the system control base address of 0x400f .e000. note: a bv in the reset column indicates the reset is a build v alue and part-specific. see the page number referenced for the reset value description. t able 8-3. internal memory register map see page description reset t ype name offset flash control offset june 14, 2007 134 luminary micro confidential-advance product information internal memory
see page description reset t ype name offset 136 flash memory address 0x0000.0000 r/w fma 0x000 137 flash memory data 0x0000.0000 r/w fmd 0x004 138 flash memory control 0x0000.0000 r/w fmc 0x008 140 flash controller raw interrupt status 0x0000.0000 ro fcris 0x00c 141 flash controller interrupt mask 0x0000.0000 r/w fcim 0x010 142 flash controller masked interrupt status and clear 0x0000.0000 r/w1c fcmisc 0x014 system control offset 144 flash memory protection read enable 0 bv r/w fmpre0 0x130 144 flash memory protection read enable 0 bv r/w fmpre0 0x200 145 flash memory protection program enable 0 bv r/w fmppe0 0x134 145 flash memory protection program enable 0 bv r/w fmppe0 0x400 143 usec reload 0x31 r/w usecrl 0x140 146 user debug 0xffff .fffe r/w user_dbg 0x1d0 147 user register 0 0x8fff .ffff r/w user_reg0 0x1e0 148 user register 1 0x8fff .ffff r/w user_reg1 0x1e4 149 flash memory protection read enable 1 0xffff .ffff r/w fmpre1 0x204 150 flash memory protection read enable 2 0xffff .ffff r/w fmpre2 0x208 151 flash memory protection read enable 3 0xffff .ffff r/w fmpre3 0x20c 152 flash memory protection program enable 1 0xffff .ffff r/w fmppe1 0x404 153 flash memory protection program enable 2 0xffff .ffff r/w fmppe2 0x408 154 flash memory protection program enable 3 0xffff .ffff r/w fmppe3 0x40c 8.5 flash register descriptions (flash control offset) the remainder of this section lists and describes the flash memory registers, in numerical order by address of fset. 135 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1: flash memory address (fma), offset 0x000 during a write operation, this register contains a 4-byte-aligned address and specifies where the data is written. during erase operations, this register contains a 1 kb-aligned address and specifies which page is erased. note that the alignment requirements must be met by software or the results of the operation are unpredictable. flash memory address (fma) base 0x400f .d000 of fset 0x000 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 offset r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field address of fset in flash where operation is performed, except for nonvolatile registers (see nonvolatile register programming on page 134 for details on values for this field). 0x0 r/w offset 31:0 june 14, 2007 136 luminary micro confidential-advance product information internal memory
register 2: flash memory data (fmd), offset 0x004 this register contains the data to be written during the programming cycle or read during the read cycle. note that the contents of this register are undefined for a read access of an execute-only block. this register is not used during the erase cycles. flash memory data (fmd) base 0x400f .d000 of fset 0x004 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 da t a r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field data value for write operation. 0x0 r/w da t a 31:0 137 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: flash memory control (fmc), offset 0x008 when this register is written, the flash controller initiates the appropriate access cycle for the location specified by the flash memory address (fma) register (see page 136 ). if the access is a write access, the data contained in the flash memory data (fmd) register (see page 137 ) is written. this is the final register written and initiates the memory operation. there are four control bits in the lower byte of this register that, when set, initiate the memory operation. the most used of these register bits are the erase and write bits. it is a programming error to write multiple control bits and the results of such an operation are unpredictable. flash memory control (fmc) base 0x400f .d000 of fset 0x008 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 wrkey wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 write erase merase comt reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field this field contains a write key , which is used to minimize the incidence of accidental flash writes. the value 0xa442 must be written into this field for a write to occur . w rites to the fmc register without this wrkey value are ignored. a read of this field returns the value 0. 0x0 wo wrkey 31:16 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15:4 commit (write) of register value to nonvolatile storage. a write of 0 has no ef fect on the state of this bit. if read, the state of the previous commit access is provided. if the previous commit access is complete, a 0 is returned; otherwise, if the commit access is not complete, a 1 is returned. this can take up to 50 s. 0 r/w comt 3 mass erase flash memory . if this bit is set, the flash main memory of the device is all erased. a write of 0 has no ef fect on the state of this bit. if read, the state of the previous mass erase access is provided. if the previous mass erase access is complete, a 0 is returned; otherwise, if the previous mass erase access is not complete, a 1 is returned. this can take up to 250 ms. 0 r/w merase 2 june 14, 2007 138 luminary micro confidential-advance product information internal memory
description reset t ype name bit/field erase a page of flash memory . if this bit is set, the page of flash main memory as specified by the contents of fma is erased. a write of 0 has no ef fect on the state of this bit. if read, the state of the previous erase access is provided. if the previous erase access is complete, a 0 is returned; otherwise, if the previous erase access is not complete, a 1 is returned. this can take up to 25 ms. 0 r/w erase 1 w rite a word into flash memory . if this bit is set, the data stored in fmd is written into the location as specified by the contents of fma . a write of 0 has no ef fect on the state of this bit. if read, the state of the previous write update is provided. if the previous write access is complete, a 0 is returned; otherwise, if the write access is not complete, a 1 is returned. this can take up to 50 s. 0 r/w write 0 139 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 4: flash controller raw interrupt status (fcris), offset 0x00c this register indicates that the flash controller has an interrupt condition. an interrupt is only signaled if the corresponding fcim register bit is set. flash controller raw interrupt status (fcris) base 0x400f .d000 of fset 0x00c t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 aris pris reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:2 programming raw interrupt status this bit indicates the current state of the programming cycle. if set, the programming cycle completed; if cleared, the programming cycle has not completed. programming cycles are either write or erase actions generated through the flash memory control (fmc) register bits (see page 138 ). 0 ro pris 1 access raw interrupt status this bit indicates if the flash was improperly accessed. if set, the program tried to access the flash counter to the policy as set in the flash memory protection read enable (fmpren) and flash memory protection program enable (fmppen) registers. otherwise, no access has tried to improperly access the flash. 0 ro aris 0 june 14, 2007 140 luminary micro confidential-advance product information internal memory
register 5: flash controller interrupt mask (fcim), offset 0x010 this register controls whether the flash controller generates interrupts to the controller . flash controller interrupt mask (fcim) base 0x400f .d000 of fset 0x010 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 amask pmask reserved r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:2 programming interrupt mask this bit controls the reporting of the programming raw interrupt status to the controller . if set, a programming-generated interrupt is promoted to the controller . otherwise, interrupts are recorded but suppressed from the controller . 0 r/w pmask 1 access interrupt mask this bit controls the reporting of the access raw interrupt status to the controller . if set, an access-generated interrupt is promoted to the controller . otherwise, interrupts are recorded but suppressed from the controller . 0 r/w amask 0 141 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 6: flash controller masked interrupt status and clear (fcmisc), offset 0x014 this register provides two functions. first, it reports the cause of an interrupt by indicating which interrupt source or sources are signalling the interrupt. second, it serves as the method to clear the interrupt reporting. flash controller masked interrupt status and clear (fcmisc) base 0x400f .d000 of fset 0x014 t ype r/w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 amisc pmisc reserved r/w1c r/w1c ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:2 programming masked interrupt status and clear this bit indicates whether an interrupt was signaled because a programming cycle completed and was not masked. this bit is cleared by writing a 1. the pris bit in the fcris register (see page 140 ) is also cleared when the pmisc bit is cleared. 0 r/w1c pmisc 1 access masked interrupt status and clear this bit indicates whether an interrupt was signaled because an improper access was attempted and was not masked. this bit is cleared by writing a 1. the aris bit in the fcris register is also cleared when the amisc bit is cleared. 0 r/w1c amisc 0 8.6 flash register descriptions (system control offset) the remainder of this section lists and describes the flash memory registers, in numerical order by address of fset. june 14, 2007 142 luminary micro confidential-advance product information internal memory
register 7: usec reload (usecrl), offset 0x140 note: of fset is relative to system control base address of 0x400f .e000 this register is provided as a means of creating a 1-s tick divider reload value for the flash controller . the internal flash has specific minimum and maximum requirements on the length of time the high voltage write pulse can be applied. it is required that this register contain the operating frequency (in mhz -1) whenever the flash is being erased or programmed. the user is required to change this value if the clocking conditions are changed for a flash erase/program operation. usec reload (usecrl) base 0x400f .e000 of fset 0x140 t ype r/w , reset 0x31 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 usec reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 1 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 mhz -1 of the controller clock when the flash is being erased or programmed. usec should be set to 0x31 (50 mhz) whenever the flash is being erased or programmed. 0x31 r/w usec 7:0 143 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 8: flash memory protection read enable 0 (fmpre0), offset 0x130 and 0x200 note: this register is aliased for backwards compatability . note: of fset is relative to system control base address of 0x400fe000. this register stores the read-only protection bits for each 2-kb flash block ( fmppen stores the execute-only bits). this register is loaded during the power-on reset sequence. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this achieves a policy of open access and programmability . the register bits may be changed by writing the specific register bit. however , this register is r/w0; the user can only change the protection bit from a 1 to a 0 (and may not change a 0 to a 1). the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. for additional information, see the "flash memory protection" section. flash memory protection read enable 0 (fmpre0) base 0x400f .d000 of fset 0x130 and 0x200 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 read_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 read_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field enables 2-kb flash blocks to be executed or read. the policies may be combined as shown in the table flash protection policy combinations. description v alue enables 256 kb of flash. 0xffffffff 0xffffffff r/w read_enable 31:0 june 14, 2007 144 luminary micro confidential-advance product information internal memory
register 9: flash memory protection program enable 0 (fmppe0), offset 0x134 and 0x400 note: this register is aliased for backwards compatability . note: of fset is relative to system control base address of 0x400fe000. this register stores the execute-only protection bits for each 2-kb flash block ( fmpren stores the execute-only bits). this register is loaded during the power-on reset sequence. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this achieves a policy of open access and programmability . the register bits may be changed by writing the specific register bit. however , this register is r/w0; the user can only change the protection bit from a 1 to a 0 (and may not change a 0 to a 1). the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. for additional information, see the "flash memory protection" section. flash memory protection program enable 0 (fmppe0) base 0x400f .d000 of fset 0x134 and 0x400 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 prog_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 prog_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field enables 2-kb flash blocks to be written or erased. the policies may be combined as shown in the table flash protection policy combinations. description v alue enables 256 kb of flash. 0xffffffff 0xffffffff r/w prog_enable 31:0 145 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 10: user debug (user_dbg), offset 0x1d0 note: of fset is relative to system control base address of 0x400fe000. this register provides a write-once mechanism to disable external debugger access to the device in addition to 27 additional bits of user-defined data. the dbg0 bit (bit 0) is set to 0 from the factory and the dbg1 bit (bit 1) is set to 1, which enables external debuggers. changing the dbg1 bit to 0 disables any external debugger access to the device permanently , starting with the next power-up cycle of the device. the notwritten bit (bit 31) indicates that the register is available to be written and is controlled through hardware to ensure that the register is only written once. user debug (user_dbg) base 0x400f .e000 of fset 0x1d0 t ype r/w , reset 0xffff .fffe 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 da t a notwritten r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 dbg0 dbg1 init1 da t a r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field specifies that this 32-bit dword has not been written. 1 r/w notwritten 31 contains the user data value. this field is initialized to all 1s and can only be written once. 0xfffffff r/w da t a 30:3 user data initialized to 1. 1 r/w init1 2 the dbg1 bit must be 1 and dbg0 must be 0 for debug to be available. 1 r/w dbg1 1 the dbg1 bit must be 1 and dbg0 must be 0 for debug to be available. 0 r/w dbg0 0 june 14, 2007 146 luminary micro confidential-advance product information internal memory
register 1 1: user register 0 (user_reg0), offset 0x1e0 note: of fset is relative to system control base address of 0x400fe000. this register provides 31 bits of user-defined data that is non-volatile and can only be written once. bit 31 indicates that the register is available to be written and is controlled through hardware to ensure that the register is only written once. the write-once characteristics of this register are useful for keeping static information like communication addresses that need to be unique per part and would otherwise require an external eeprom or other non-volatile device. user register 0 (user_reg0) base 0x400f .e000 of fset 0x1e0 t ype r/w , reset 0x8fff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 da t a notwritten r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field specifies that this 32-bit dword has not been written. 1 r/w notwritten 31 contains the user data value. this field is initialized to all 1s and can only be written once. 0xfffffff r/w da t a 30:0 147 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 12: user register 1 (user_reg1), offset 0x1e4 note: of fset is relative to system control base address of 0x400fe000. this register provides 31 bits of user-defined data that is non-volatile and can only be written once. bit 31 indicates that the register is available to be written and is controlled through hardware to ensure that the register is only written once. the write-once characteristics of this register are useful for keeping static information like communication addresses that need to be unique per part and would otherwise require an external eeprom or other non-volatile device. user register 1 (user_reg1) base 0x400f .e000 of fset 0x1e4 t ype r/w , reset 0x8fff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 da t a notwritten r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field specifies that this 32-bit dword has not been written. 1 r/w notwritten 31 contains the user data value. this field is initialized to all 1s and can only be written once. 0xfffffff r/w da t a 30:0 june 14, 2007 148 luminary micro confidential-advance product information internal memory
register 13: flash memory protection read enable 1 (fmpre1), offset 0x204 note: of fset is relative to system control base address of 0x400fe000. this register stores the read-only protection bits for each 2-kb flash block ( fmppen stores the execute-only bits). this register is loaded during the power-on reset sequence. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this achieves a policy of open access and programmability . the register bits may be changed by writing the specific register bit. however , this register is r/w0; the user can only change the protection bit from a 1 to a 0 (and may not change a 0 to a 1). the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. for additional information, see the "flash memory protection" section. flash memory protection read enable 1 (fmpre1) base 0x400f .e000 of fset 0x204 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 read_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 read_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field enables 2-kb flash blocks to be executed or read. the policies may be combined as shown in the table flash protection policy combinations. description v alue enables 256 kb of flash. 0xffffffff 0xffffffff r/w read_enable 31:0 149 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 14: flash memory protection read enable 2 (fmpre2), offset 0x208 note: of fset is relative to system control base address of 0x400fe000. this register stores the read-only protection bits for each 2-kb flash block ( fmppen stores the execute-only bits). this register is loaded during the power-on reset sequence. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this achieves a policy of open access and programmability . the register bits may be changed by writing the specific register bit. however , this register is r/w0; the user can only change the protection bit from a 1 to a 0 (and may not change a 0 to a 1). the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. for additional information, see the "flash memory protection" section. flash memory protection read enable 2 (fmpre2) base 0x400f .e000 of fset 0x208 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 read_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 read_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field enables 2-kb flash blocks to be executed or read. the policies may be combined as shown in the table flash protection policy combinations. description v alue enables 256 kb of flash. 0xffffffff 0xffffffff r/w read_enable 31:0 june 14, 2007 150 luminary micro confidential-advance product information internal memory
register 15: flash memory protection read enable 3 (fmpre3), offset 0x20c note: of fset is relative to system control base address of 0x400fe000. this register stores the read-only protection bits for each 2-kb flash block ( fmppen stores the execute-only bits). this register is loaded during the power-on reset sequence. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this achieves a policy of open access and programmability . the register bits may be changed by writing the specific register bit. however , this register is r/w0; the user can only change the protection bit from a 1 to a 0 (and may not change a 0 to a 1). the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. for additional information, see the "flash memory protection" section. flash memory protection read enable 3 (fmpre3) base 0x400f .e000 of fset 0x20c t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 read_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 read_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field enables 2-kb flash blocks to be executed or read. the policies may be combined as shown in the table flash protection policy combinations. description v alue enables 256 kb of flash. 0xffffffff 0xffffffff r/w read_enable 31:0 151 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 16: flash memory protection program enable 1 (fmppe1), offset 0x404 note: of fset is relative to system control base address of 0x400fe000. this register stores the execute-only protection bits for each 2-kb flash block ( fmpren stores the execute-only bits). this register is loaded during the power-on reset sequence. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this achieves a policy of open access and programmability . the register bits may be changed by writing the specific register bit. however , this register is r/w0; the user can only change the protection bit from a 1 to a 0 (and may not change a 0 to a 1). the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. for additional information, see the "flash memory protection" section. flash memory protection program enable 1 (fmppe1) base 0x400f .e000 of fset 0x404 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 prog_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 prog_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field enables 2-kb flash blocks to be written or erased. the policies may be combined as shown in the table flash protection policy combinations. description v alue enables 256 kb of flash. 0xffffffff 0xffffffff r/w prog_enable 31:0 june 14, 2007 152 luminary micro confidential-advance product information internal memory
register 17: flash memory protection program enable 2 (fmppe2), offset 0x408 note: of fset is relative to system control base address of 0x400fe000. this register stores the execute-only protection bits for each 2-kb flash block ( fmpren stores the execute-only bits). this register is loaded during the power-on reset sequence. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this achieves a policy of open access and programmability . the register bits may be changed by writing the specific register bit. however , this register is r/w0; the user can only change the protection bit from a 1 to a 0 (and may not change a 0 to a 1). the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. for additional information, see the "flash memory protection" section. flash memory protection program enable 2 (fmppe2) base 0x400f .e000 of fset 0x408 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 prog_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 prog_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field enables 2-kb flash blocks to be written or erased. the policies may be combined as shown in the table flash protection policy combinations. description v alue enables 256 kb of flash. 0xffffffff 0xffffffff r/w prog_enable 31:0 153 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 18: flash memory protection program enable 3 (fmppe3), offset 0x40c note: of fset is relative to system control base address of 0x400fe000. this register stores the execute-only protection bits for each 2-kb flash block ( fmpren stores the execute-only bits). this register is loaded during the power-on reset sequence. the factory settings for the fmpren and fmppen registers are a value of 1 for all implemented banks. this achieves a policy of open access and programmability . the register bits may be changed by writing the specific register bit. however , this register is r/w0; the user can only change the protection bit from a 1 to a 0 (and may not change a 0 to a 1). the changes are not permanent until the register is committed (saved), at which point the bit change is permanent. if a bit is changed from a 1 to a 0 and not committed, it may be restored by executing a power-on reset sequence. for additional information, see the "flash memory protection" section. flash memory protection program enable 3 (fmppe3) base 0x400f .e000 of fset 0x40c t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 prog_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 prog_enable r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field enables 2-kb flash blocks to be written or erased. the policies may be combined as shown in the table flash protection policy combinations. description v alue enables 256 kb of flash. 0xffffffff 0xffffffff r/w prog_enable 31:0 june 14, 2007 154 luminary micro confidential-advance product information internal memory
9 general-purpose input/outputs (gpios) gpio the gpio module is composed of seven physical gpio blocks, each corresponding to an individual gpio port (port a, port b, port c, port d, port e, port f , and port g, ). the gpio module is firm-compliant and supports 3-38 programmable input/output pins, depending on the peripherals being used. the gpio module has the following features: programmable control for gpio interrupts C interrupt generation masking C edge-triggered on rising, falling, or both C level-sensitive on high or low values 5-v-tolerant input/outputs bit masking in both read and write operations through address lines programmable control for gpio pad configuration C w eak pull-up or pull-down resistors C 2-ma, 4-ma, and 8-ma pad drive C slew rate control for the 8-ma drive C open drain enables C digital input enables 9.1 function description important: all gpio pins are tri-stated by default ( gpioafsel =0, gpioden=0, gpiopdr=0, and gpiopur =0), with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). the jt ag/swd pins default to their jt ag/swd functionality ( gpioafsel =1, gpioden=1 and gpiopur =1). a power-on-reset ( por ) or asserting rst puts both groups of pins back to their default state. each gpio port is a separate hardware instantiation of the same physical block. the lm3s8938 microcontroller contains seven ports and thus seven of these physical gpio blocks. 9.1.1 data control the data control registers allow software to configure the operational modes of the gpios. the data direction register configures the gpio as an input or an output while the data register either captures incoming data or drives it out to the pads. 9.1.1.1 data direction operation the gpio direction (gpiodir) register (see page 163 ) is used to configure each individual pin as an input or output. when the data direction bit is set to 0, the gpio is configured as an input and 155 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
the corresponding data register bit will capture and store the value on the gpio port. when the data direction bit is set to 1, the gpio is configured as an output and the corresponding data register bit will be driven out on the gpio port. 9.1.1.2 data register operation t o aid in the ef ficiency of software, the gpio ports allow for the modification of individual bits in the gpio data (gpioda t a) register (see page 162 ) by using bits [9:2] of the address bus as a mask. this allows software drivers to modify individual gpio pins in a single instruction, without af fecting the state of the other pins. this is in contrast to the "typical" method of doing a read-modify-write operation to set or clear an individual gpio pin. t o accommodate this feature, the gpioda t a register covers 256 locations in the memory map. during a write, if the address bit associated with that data bit is set to 1, the value of the gpioda t a register is altered. if it is cleared to 0, it is left unchanged. for example, writing a value of 0xeb to the address gpioda t a + 0x098 would yield as shown in figure 9-1 on page 156 , where u is data unchanged by the write. figure 9-1. gpioda t a w rite example during a read, if the address bit associated with the data bit is set to 1, the value is read. if the address bit associated with the data bit is set to 0, it is read as a zero, regardless of its actual value. for example, reading address gpioda t a + 0x0c4 yields as shown in figure 9-2 on page 156 . figure 9-2. gpioda t a read example 9.1.2 interrupt control the interrupt capabilities of each gpio port are controlled by a set of seven registers. with these registers, it is possible to select the source of the interrupt, its polarity , and the edge properties. when one or more gpio inputs cause an interrupt, a single interrupt output is sent to the interrupt controller for the entire gpio port. for edge-triggered interrupts, software must clear the interrupt to enable any further interrupts. for a level-sensitive interrupt, it is assumed that the external source holds the level constant for the interrupt to be recognized by the controller . three registers are required to define the edge or sense that causes interrupts: june 14, 2007 156 luminary micro confidential-advance product information general-purpose input/outputs (gpios) 0 1 0 0 1 1 0 0 1 0 u 1 u u 0 1 u u 9 8 7 6 5 4 3 2 1 0 1 1 1 0 0 1 1 1 7 6 5 4 3 2 1 0 gpioda t a 0xeb 0x098 addr[9:2] 0 1 0 1 0 0 0 1 0 0 0 1 0 1 0 0 0 0 9 8 7 6 5 4 3 2 1 0 0 1 1 1 1 1 1 0 7 6 5 4 3 2 1 0 returned v alue gpioda t a 0x0c4 addr[9:2]
gpio interrupt sense (gpiois) register (see page 164 ) gpio interrupt both edges (gpioibe) register (see page 165 ) gpio interrupt event (gpioiev) register (see page 166 ) interrupts are enabled/disabled via the gpio interrupt mask (gpioim) register (see page 167 ). when an interrupt condition occurs, the state of the interrupt signal can be viewed in two locations: the gpio raw interrupt status (gpioris) and gpio masked interrupt status (gpiomis) registers (see page 168 and page 169 ). as the name implies, the gpiomis register only shows interrupt conditions that are allowed to be passed to the controller . the gpioris register indicates that a gpio pin meets the conditions for an interrupt, but has not necessarily been sent to the controller . in addition to providing gpio functionality , pb4 can also be used as an external trigger for the adc. if pb4 is configured as a non-masked interrupt pin ( gpioim is set to 1), not only is an interrupt for portb generated, but an external trigger signal is sent to the adc. if the adc event multiplexer select (adcemux) register is configured to use the external trigger , an adc conversion is initiated. if no other portb pins are being used to generate interrupts, the arm integrated nested v ectored interrupt controller (nvic) interrupt set enable (setna) register can disable the portb interrupts and the adc interrupt can be used to read back the converted data. otherwise, the portb interrupt handler needs to ignore and clear interrupts on b4, and wait for the adc interrupt or the adc interrupt needs to be disabled in the setna register and the portb interrupt handler polls the adc registers until the conversion is completed. interrupts are cleared by writing a 1 to the gpio interrupt clear (gpioicr) register (see page 170 ). when programming the following interrupt control registers, the interrupts should be masked ( gpioim set to 0). w riting any value to an interrupt control register ( gpiois , gpioibe , or gpioiev ) can generate a spurious interrupt if the corresponding bits are enabled. 9.1.3 mode control the gpio pins can be controlled by either hardware or software. when hardware control is enabled via the gpio alternate function select (gpioafsel) register (see page 171 ), the pin state is controlled by its alternate function (that is, the peripheral). software control corresponds to gpio mode, where the gpioda t a register is used to read/write the corresponding pins. 9.1.4 commit control the commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. w rites to protected bits of the gpio alternate function select (gpioafsel) register (see page 171 ) are not committed to storage unless the gpio lock (gpiolock) register (see page 181 ) has been unlocked and the appropriate bits of the gpio commit (gpiocr) register (see page 182 ) have been set to 1. 9.1.5 pad control the pad control registers allow for gpio pad configuration by software based on the application requirements. the pad control registers include the gpiodr2r , gpiodr4r , gpiodr8r , gpioodr , gpiopur , gpiopdr , gpioslr , and gpioden registers. 157 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
9.1.6 identification the identification registers configured at reset allow software to detect and identify the module as a gpio block. the identification registers include the gpioperiphid0 - gpioperiphid7 registers as well as the gpiopcellid0 - gpiopcellid3 registers. 9.2 initialization and configuration t o use the gpio, the peripheral clock must be enabled by setting the appropriate gpio port bit field ( gpion ) in the rcgc2 register . on reset, all gpio pins (except for the five jt ag pins) are configured out of reset to be undriven (tristate): gpioafsel =0, gpioden =0, gpiopdr =0, and gpiopur =0. t able 9-1 on page 158 shows all possible configurations of the gpio pads and the control register settings required to achieve them. t able 9-2 on page 158 shows how a rising edge interrupt would be configured for pin 2 of a gpio port. t able 9-1. gpio pad configuration examples gpio register bit v alue a configuration slr dr8r dr4r dr2r pdr pur den odr dir afsel x x x x ? ? 1 0 0 0 digital input (gpio) ? ? ? ? ? ? 1 0 1 0 digital output (gpio) x x x x x x 1 1 0 0 open drain input (gpio) ? ? ? ? x x 1 1 1 0 open drain output (gpio) ? ? ? ? x x 1 1 x 1 open drain input/output (i 2 c) x x x x ? ? 1 0 x 1 digital input (t imer ccp) ? ? ? ? ? ? 1 0 x 1 digital output (t imer pwm) ? ? ? ? ? ? 1 0 x 1 digital input/output (ssi) ? ? ? ? ? ? 1 0 x 1 digital input/output (uar t) x x x x 0 0 0 0 0 0 analog input (comparator) ? ? ? ? ? ? 1 0 x 1 digital output (comparator) a. x=ignored (dont care bit) ?=can be either 0 or 1, depending on the configuration t able 9-2. gpio interrupt configuration example pin 2 bit v alue a desired interrupt event t rigger register 0 1 2 3 4 5 6 7 x x 0 x x x x x 0=edge 1=level gpiois june 14, 2007 158 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
pin 2 bit v alue a desired interrupt event t rigger register 0 1 2 3 4 5 6 7 x x 0 x x x x x 0=single edge 1=both edges gpioibe x x 1 x x x x x 0=low level, or negative edge 1=high level, or positive edge gpioiev 0 0 1 0 0 0 0 0 0=masked 1=not masked gpioim a. x=ignored (dont care bit) 9.3 register map t able 9-3 on page 160 lists the gpio registers. the of fset listed is a hexadecimal increment to the register s address, relative to that gpio port s base address: gpio port a: 0x4000.4000 gpio port b: 0x4000.5000 gpio port c: 0x4000.6000 gpio port d: 0x4000.7000 gpio port e: 0x4002.4000 gpio port f: 0x4002.5000 gpio port g: 0x4002.6000 important: the gpio registers in this chapter are duplicated in each gpio block, however , depending on the block, all eight bits may not be connected to a gpio pad. in those cases, writing to those unconnected bits has no ef fect and reading those unconnected bits returns no meaningful data. note: the default reset value for the gpioafsel , gpiopur , and gpioden registers are 0x0000.0000 for all gpio pins, with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). these five pins default to jt ag/swd functionality . because of this, the default reset value of these registers for gpio port b is 0x0000.0080 while the default reset value for port c is 0x0000.000f . the default register type for the gpiocr register is ro for all gpio pins, with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). these five pins are currently the only gpios that are protected by the gpiocr register . because of this, the register type for gpio port b7 and gpio port c[3:0] is r/w . 159 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
the default reset value for the gpiocr register is 0x0000.00ff for all gpio pins, with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). t o ensure that the jt ag port is not accidentally programmed as a gpio, these five pins default to non-commitable. because of this, the default reset value of gpiocr for gpio port b is 0x0000.007f while the default reset value of gpiocr for port c is 0x0000.00f0. t able 9-3. gpio register map see page description reset t ype name offset 162 gpio data 0x0000.0000 r/w gpioda t a 0x000 163 gpio direction 0x0000.0000 r/w gpiodir 0x400 164 gpio interrupt sense 0x0000.0000 r/w gpiois 0x404 165 gpio interrupt both edges 0x0000.0000 r/w gpioibe 0x408 166 gpio interrupt event 0x0000.0000 r/w gpioiev 0x40c 167 gpio interrupt mask 0x0000.0000 r/w gpioim 0x410 168 gpio raw interrupt status 0x0000.0000 ro gpioris 0x414 169 gpio masked interrupt status 0x0000.0000 ro gpiomis 0x418 170 gpio interrupt clear 0x0000.0000 w1c gpioicr 0x41c 171 gpio alternate function select - r/w gpioafsel 0x420 173 gpio 2-ma drive select 0x0000.00ff r/w gpiodr2r 0x500 174 gpio 4-ma drive select 0x0000.0000 r/w gpiodr4r 0x504 175 gpio 8-ma drive select 0x0000.0000 r/w gpiodr8r 0x508 176 gpio open drain select 0x0000.0000 r/w gpioodr 0x50c 177 gpio pull-up select - r/w gpiopur 0x510 178 gpio pull-down select 0x0000.0000 r/w gpiopdr 0x514 179 gpio slew rate control select 0x0000.0000 r/w gpioslr 0x518 180 gpio digital enable - r/w gpioden 0x51c 181 gpio lock 0x0000.0001 r/w gpiolock 0x520 182 gpio commit - - gpiocr 0x524 184 gpio peripheral identification 4 0x0x0000.0000 ro gpioperiphid4 0xfd0 185 gpio peripheral identification 5 0x0x0000.0000 ro gpioperiphid5 0xfd4 186 gpio peripheral identification 6 0x0x0000.0000 ro gpioperiphid6 0xfd8 187 gpio peripheral identification 7 0x0x0000.0000 ro gpioperiphid7 0xfdc 188 gpio peripheral identification 0 0x0x0000.0061 ro gpioperiphid0 0xfe0 189 gpio peripheral identification 1 0x0x0000.0000 ro gpioperiphid1 0xfe4 190 gpio peripheral identification 2 0x0x0000.0018 ro gpioperiphid2 0xfe8 191 gpio peripheral identification 3 0x0x0000.0001 ro gpioperiphid3 0xfec june 14, 2007 160 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
see page description reset t ype name offset 192 gpio primecell identification 0 0x0x0000.000d ro gpiopcellid0 0xff0 193 gpio primecell identification 1 0x0x0000.00f0 ro gpiopcellid1 0xff4 194 gpio primecell identification 2 0x0x0000.0005 ro gpiopcellid2 0xff8 195 gpio primecell identification 3 0x0x0000.00b1 ro gpiopcellid3 0xffc 9.4 register descriptions the remainder of this section lists and describes the gpio registers, in numerical order by address of fset. 161 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1: gpio data (gpioda t a), offset 0x000 the gpioda t a register is the data register . in software control mode, values written in the gpioda t a register are transferred onto the gpio port pins if the respective pins have been configured as outputs through the gpio direction (gpiodir) register (see page 163 ). in order to write to gpioda t a , the corresponding bits in the mask, resulting from the address bus bits [9:2], must be high. otherwise, the bit values remain unchanged by the write. similarly , the values read from this register are determined for each bit by the mask bit derived from the address used to access the data register , bits [9:2]. bits that are 1 in the address mask cause the corresponding bits in gpioda t a to be read, and bits that are 0 in the address mask cause the corresponding bits in gpioda t a to be read as 0, regardless of their value. a read from gpioda t a returns the last bit value written if the respective pins are configured as outputs, or it returns the value on the corresponding input pin when these are configured as inputs. all bits are cleared by a reset. gpio data (gpioda t a) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x000 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio data this register is virtually mapped to 256 locations in the address space. t o facilitate the reading and writing of data to these registers by independent drivers, the data read from and the data written to the registers are masked by the eight address lines ipaddr[9:2] . reads from this register return its current state. w rites to this register only af fect bits that are not masked by ipaddr[9:2] and are configured as outputs. see data register operation on page 156 for examples of reads and writes. 0 r/w da t a 7:0 june 14, 2007 162 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 2: gpio direction (gpiodir), offset 0x400 the gpiodir register is the data direction register . bits set to 1 in the gpiodir register configure the corresponding pin to be an output, while bits set to 0 configure the pins to be inputs. all bits are cleared by a reset, meaning all gpio pins are inputs by default. gpio direction (gpiodir) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x400 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 dir reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio data direction 0: pins are inputs. 1: pins are outputs. 0x00 r/w dir 7:0 163 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: gpio interrupt sense (gpiois), offset 0x404 the gpiois register is the interrupt sense register . bits set to 1 in gpiois configure the corresponding pins to detect levels, while bits set to 0 configure the pins to detect edges. all bits are cleared by a reset. gpio interrupt sense (gpiois) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x404 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 is reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio interrupt sense 0: edge on corresponding pin is detected (edge-sensitive). 1: level on corresponding pin is detected (level-sensitive). 0x00 r/w is 7:0 june 14, 2007 164 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 4: gpio interrupt both edges (gpioibe), offset 0x408 the gpioibe register is the interrupt both-edges register . when the corresponding bit in the gpio interrupt sense (gpiois) register (see page 164 ) is set to detect edges, bits set to high in gpioibe configure the corresponding pin to detect both rising and falling edges, regardless of the corresponding bit in the gpio interrupt event (gpioiev) register (see page 166 ). clearing a bit configures the pin to be controlled by gpioiev . all bits are cleared by a reset. gpio interrupt both edges (gpioibe) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x408 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ibe reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio interrupt both edges 0: interrupt generation is controlled by the gpio interrupt event (gpioiev) register (see page 142). 1: both edges on the corresponding pin trigger an interrupt. note: single edge is determined by the corresponding bit in gpioiev . 0x00 r/w ibe 7:0 165 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: gpio interrupt event (gpioiev), offset 0x40c the gpioiev register is the interrupt event register . bits set to high in gpioiev configure the corresponding pin to detect rising edges or high levels, depending on the corresponding bit value in the gpio interrupt sense (gpiois) register (see page 164 ). clearing a bit configures the pin to detect falling edges or low levels, depending on the corresponding bit value in gpiois . all bits are cleared by a reset. gpio interrupt event (gpioiev) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x40c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 iev reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio interrupt event 0: falling edge or low levels on corresponding pins trigger interrupts. 1: rising edge or high levels on corresponding pins trigger interrupts. 0x00 r/w iev 7:0 june 14, 2007 166 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 6: gpio interrupt mask (gpioim), offset 0x410 the gpioim register is the interrupt mask register . bits set to high in gpioim allow the corresponding pins to trigger their individual interrupts and the combined gpiointr line. clearing a bit disables interrupt triggering on that pin. all bits are cleared by a reset. gpio interrupt mask (gpioim) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x410 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ime reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio interrupt mask enable 0: corresponding pin interrupt is masked. 1: corresponding pin interrupt is not masked. 0x00 r/w ime 7:0 167 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: gpio raw interrupt status (gpioris), offset 0x414 the gpioris register is the raw interrupt status register . bits read high in gpioris reflect the status of interrupt trigger conditions detected (raw , prior to masking), indicating that all the requirements have been met, before they are finally allowed to trigger by the gpio interrupt mask (gpioim) register (see page 167 ). bits read as zero indicate that corresponding input pins have not initiated an interrupt. all bits are cleared by a reset. gpio raw interrupt status (gpioris) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x414 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ris reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio interrupt raw status reflect the status of interrupt trigger condition detection on pins (raw , prior to masking). 0: corresponding pin interrupt requirements not met. 1: corresponding pin interrupt has met requirements. 0x00 ro ris 7:0 june 14, 2007 168 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 8: gpio masked interrupt status (gpiomis), offset 0x418 the gpiomis register is the masked interrupt status register . bits read high in gpiomis reflect the status of input lines triggering an interrupt. bits read as low indicate that either no interrupt has been generated, or the interrupt is masked. in addition to providing gpio functionality , pb4 can also be used as an external trigger for the adc. if pb4 is configured as a non-masked interrupt pin ( gpioim is set to 1), not only is an interrupt for portb generated, but an external trigger signal is sent to the adc. if the adc event multiplexer select (adcemux) register is configured to use the external trigger , an adc conversion is initiated. if no other portb pins are being used to generate interrupts, the arm integrated nested v ectored interrupt controller (nvic) interrupt set enable (setna) register can disable the portb interrupts and the adc interrupt can be used to read back the converted data. otherwise, the portb interrupt handler needs to ignore and clear interrupts on b4, and wait for the adc interrupt or the adc interrupt needs to be disabled in the setna register and the portb interrupt handler polls the adc registers until the conversion is completed. gpiomis is the state of the interrupt after masking. gpio masked interrupt status (gpiomis) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x418 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mis reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio masked interrupt status masked value of interrupt due to corresponding pin. 0: corresponding gpio line interrupt not active. 1: corresponding gpio line asserting interrupt. 0x00 ro mis 7:0 169 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 9: gpio interrupt clear (gpioicr), offset 0x41c the gpioicr register is the interrupt clear register . w riting a 1 to a bit in this register clears the corresponding interrupt edge detection logic register . w riting a 0 has no ef fect. gpio interrupt clear (gpioicr) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x41c t ype w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ic reserved w1c w1c w1c w1c w1c w1c w1c w1c ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio interrupt clear 0: corresponding interrupt is unaf fected. 1: corresponding interrupt is cleared. 0x00 w1c ic 7:0 june 14, 2007 170 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 10: gpio alternate function select (gpioafsel), offset 0x420 the gpioafsel register is the mode control select register . w riting a 1 to any bit in this register selects the hardware control for the corresponding gpio line. all bits are cleared by a reset, therefore no gpio line is set to hardware control by default. the commit control registers provide a layer of protection against accidental programming of critical hardware peripherals. w rites to protected bits of the gpio alternate function select (gpioafsel) register (see page 171 ) are not committed to storage unless the gpio lock (gpiolock) register (see page 181 ) has been unlocked and the appropriate bits of the gpio commit (gpiocr) register (see page 182 ) have been set to 1. important: all gpio pins are tri-stated by default ( gpioafsel =0, gpioden=0, gpiopdr=0, and gpiopur =0), with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). the jt ag/swd pins default to their jt ag/swd functionality ( gpioafsel =1, gpioden=1 and gpiopur =1). a power-on-reset ( por ) or asserting rst puts both groups of pins back to their default state. caution C if the jt ag pins ar e used as gpios in a design, pb7 and pc2 cannot have external pull-down r esistors connected to both of them at the same time. if both pins ar e pulled low during r eset, the contr oller has unpr edictable behavior . if this happens, r emove one or both of the pull-down r esistors, and apply rst or power-cycle the part. in addition, it is possible to cr eate a softwar e sequence that pr events the debugger fr om connecting to the stellaris ? micr ocontr oller . if the pr ogram code loaded into fash immediately changes the jt ag pins to their gpio functionality , the debugger may not have enough time to connect and halt the contr oller befor e the jt ag pin functionality switches. this may lock the debugger out of the part. this can be avoided with a softwar e r outine that r estor es jt ag functionality based on an external or softwar e trigger . gpio alternate function select (gpioafsel) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x420 t ype r/w , reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 afsel reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype - - - - - - - - 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 171 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field gpio alternate function select 0: software control of corresponding gpio line (gpio mode). 1: hardware control of corresponding gpio line (alternate hardware function). note: the default reset value for the gpioafsel , gpiopur , and gpioden registers are 0x0000.0000 for all gpio pins, with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). these five pins default to jt ag/swd functionality . because of this, the default reset value of these registers for gpio port b is 0x0000.0080 while the default reset value for port c is 0x0000.000f . - r/w afsel 7:0 june 14, 2007 172 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 1 1: gpio 2-ma drive select (gpiodr2r), offset 0x500 the gpiodr2r register is the 2-ma drive control register . it allows for each gpio signal in the port to be individually configured without af fecting the other pads. when writing a drv2 bit for a gpio signal, the corresponding drv4 bit in the gpiodr4r register and the drv8 bit in the gpiodr8r register are automatically cleared by hardware. gpio 2-ma drive select (gpiodr2r) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x500 t ype r/w , reset 0x0000.00ff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 dr v2 reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 output pad 2-ma drive enable a write of 1 to either gpiodr4[n] or gpiodr8[n] clears the corresponding 2-ma enable bit. the change is ef fective on the second clock cycle after the write. 0xff r/w dr v2 7:0 173 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 12: gpio 4-ma drive select (gpiodr4r), offset 0x504 the gpiodr4r register is the 4-ma drive control register . it allows for each gpio signal in the port to be individually configured without af fecting the other pads. when writing the drv4 bit for a gpio signal, the corresponding drv2 bit in the gpiodr2r register and the drv8 bit in the gpiodr8r register are automatically cleared by hardware. gpio 4-ma drive select (gpiodr4r) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x504 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 dr v4 reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 output pad 4-ma drive enable a write of 1 to either gpiodr2[n] or gpiodr8[n] clears the corresponding 4-ma enable bit. the change is ef fective on the second clock cycle after the write. 0x00 r/w dr v4 7:0 june 14, 2007 174 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 13: gpio 8-ma drive select (gpiodr8r), offset 0x508 the gpiodr8r register is the 8-ma drive control register . it allows for each gpio signal in the port to be individually configured without af fecting the other pads. when writing the drv8 bit for a gpio signal, the corresponding drv2 bit in the gpiodr2r register and the drv4 bit in the gpiodr4r register are automatically cleared by hardware. gpio 8-ma drive select (gpiodr8r) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x508 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 dr v8 reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 output pad 8-ma drive enable a write of 1 to either gpiodr2[n] or gpiodr4[n] clears the corresponding 8-ma enable bit. the change is ef fective on the second clock cycle after the write. 0x00 r/w dr v8 7:0 175 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 14: gpio open drain select (gpioodr), offset 0x50c the gpioodr register is the open drain control register . setting a bit in this register enables the open drain configuration of the corresponding gpio pad. when open drain mode is enabled, the corresponding bit should also be set in the gpio digital input enable (gpioden) register (see page 180 ). corresponding bits in the drive strength registers ( gpiodr2r , gpiodr4r , gpiodr8r , and gpioslr ) can be set to achieve the desired rise and fall times. the gpio acts as an open drain input if the corresponding bit in the gpiodir register is set to 0; and as an open drain output when set to 1. when using the i 2 c module, the gpio alternate function select (gpioafsel) register bit for pb2 and pb3 should be set to 1 (see examples in initialization and configuration on page 158 ). gpio open drain select (gpioodr) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x50c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ode reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 output pad open drain enable 0: open drain configuration is disabled. 1: open drain configuration is enabled. 0x00 r/w ode 7:0 june 14, 2007 176 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 15: gpio pull-up select (gpiopur), offset 0x510 the gpiopur register is the pull-up control register . when a bit is set to 1, it enables a weak pull-up resistor on the corresponding gpio signal. setting a bit in gpiopur automatically clears the corresponding bit in the gpio pull-down select (gpiopdr) register (see page 178 ). gpio pull-up select (gpiopur) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x510 t ype r/w , reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pue reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype - - - - - - - - 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 pad w eak pull-up enable a write of 1 to gpiopdr[n] clears the corresponding gpiopur[n] enables. the change is ef fective on the second clock cycle after the write. note: the default reset value for the gpioafsel , gpiopur , and gpioden registers are 0x0000.0000 for all gpio pins, with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). these five pins default to jt ag/swd functionality . because of this, the default reset value of these registers for gpio port b is 0x0000.0080 while the default reset value for port c is 0x0000.000f . - r/w pue 7:0 177 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 16: gpio pull-down select (gpiopdr), offset 0x514 the gpiopdr register is the pull-down control register . when a bit is set to 1, it enables a weak pull-down resistor on the corresponding gpio signal. setting a bit in gpiopdr automatically clears the corresponding bit in the gpio pull-up select (gpiopur) register (see page 177 ). gpio pull-down select (gpiopdr) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x514 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pde reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 pad w eak pull-down enable a write of 1 to gpiopur[n] clears the corresponding gpiopdr[n] enables. the change is ef fective on the second clock cycle after the write. 0x00 r/w pde 7:0 june 14, 2007 178 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 17: gpio slew rate control select (gpioslr), offset 0x518 the gpioslr register is the slew rate control register . slew rate control is only available when using the 8-ma drive strength option via the gpio 8-ma drive select (gpiodr8r) register (see page 175 ). gpio slew rate control select (gpioslr) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x518 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 srl reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 slew rate limit enable (8-ma drive only) 0: slew rate control disabled. 1: slew rate control enabled. 0 r/w srl 7:0 179 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 18: gpio digital enable (gpioden), offset 0x51c the gpioden register is the digital enable register . by default, with the exception of the gpio signals used for jt ag/swd function, all other gpio signals are configured out of reset to be undriven (tristate). their digital function is disabled; they do not drive a logic value on the pin and they do not allow the pin voltage into the gpio receiver . t o use the pin in a digital function (either gpio or alternate function), the corresponding gpioden bit must be set. gpio digital enable (gpioden) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x51c t ype r/w , reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 den reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype - - - - - - - - 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 digital enable 0: digital functions disabled. 1: digital functions enabled. note: the default reset value for the gpioafsel , gpiopur , and gpioden registers are 0x0000.0000 for all gpio pins, with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). these five pins default to jt ag/swd functionality . because of this, the default reset value of these registers for gpio port b is 0x0000.0080 while the default reset value for port c is 0x0000.000f . - r/w den 7:0 june 14, 2007 180 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 19: gpio lock (gpiolock), offset 0x520 the gpiolock register enables write access to the gpiocr register (see page 182 ). w riting 0x1acce551 to the gpiolock register will unlock the gpiocr register . w riting any other value to the gpiolock register re-enables the locked state. reading the gpiolock register returns the lock status rather than the 32-bit value that was previously written. therefore, when write accesses are disabled, or locked, reading the gpiolock register returns 0x00000001. when write accesses are enabled, or unlocked, reading the gpiolock register returns 0x00000000. gpio lock (gpiolock) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x520 t ype r/w , reset 0x0000.0001 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 lock r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 lock r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field gpio lock a write of the value 0x1acce551 unlocks the gpio commit register for write access. a write of any other value reapplies the lock, preventing any register updates. a read of this register returns the following values: locked: 0x00000001 unlocked: 0x00000000 0x00000001 r/w lock 31:0 181 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 20: gpio commit (gpiocr), offset 0x524 the gpiocr register is the commit register . the value of the gpiocr register determines which bits of the gpioafsel register will be committed when a write to the gpioafsel register is performed. if a bit in the gpiocr register is a zero, the data being written to the corresponding bit in the gpioafsel register will not be committed and will retain its previous value. if a bit in the gpiocr register is a one, the data being written to the corresponding bit of the gpioafsel register will be committed to the register and will reflect the new value. the contents of the gpiocr register can only be modified if the gpiolock register is unlocked. w rites to the gpiocr register will be ignored if the gpiolock register is locked. important: this register is designed to prevent accidental programming of the gpioafsel registers that control connectivity to the jt ag/swd debug hardware. by initializing the bits of the gpiocr register to 0 for pb7 and pc[3:0] , the jt ag/swd debug port can only be converted to gpios through a deliberate set of writes to the gpiolock , gpiocr , and gpioafsel registers. because this protection is currently only implemented on the jt ag/swd pins on pb7 and pc[3:0] , all of the other bits in the gpiocr registers cannot be written with 0x0. these bits are hardwired to 0x1, ensuring that it is always possible to commit new values to the gpioafsel register bits of these other pins. gpio commit (gpiocr) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0x524 t ype -, reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cr reserved - - - - - - - - ro ro ro ro ro ro ro ro t ype - - - - - - - - 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 june 14, 2007 182 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
description reset t ype name bit/field gpio commit on a bit-wise basis, any bit set allows the corresponding gpioafsel bit to be set to its alternate function. note: the default register type for the gpiocr register is ro for all gpio pins, with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). these five pins are currently the only gpios that are protected by the gpiocr register . because of this, the register type for gpio port b7 and gpio port c[3:0] is r/w . the default reset value for the gpiocr register is 0x0000.00ff for all gpio pins, with the exception of the five jt ag/swd pins ( pb7 and pc[3:0] ). t o ensure that the jt ag port is not accidentally programmed as a gpio, these five pins default to non-commitable. because of this, the default reset value of gpiocr for gpio port b is 0x0000.007f while the default reset value of gpiocr for port c is 0x0000.00f0. - - cr 7:0 183 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 21: gpio peripheral identification 4 (gpioperiphid4), offset 0xfd0 the gpioperiphid4 , gpioperiphid5 , gpioperiphid6 , and gpioperiphid7 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register , used by software to identify the peripheral. gpio peripheral identification 4 (gpioperiphid4) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xfd0 t ype ro, reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid4 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio peripheral id register[7:0] 0x00 ro pid4 7:0 june 14, 2007 184 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 22: gpio peripheral identification 5 (gpioperiphid5), offset 0xfd4 the gpioperiphid4 , gpioperiphid5 , gpioperiphid6 , and gpioperiphid7 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register , used by software to identify the peripheral. gpio peripheral identification 5 (gpioperiphid5) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xfd4 t ype ro, reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid5 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio peripheral id register[15:8] 0x00 ro pid5 7:0 185 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 23: gpio peripheral identification 6 (gpioperiphid6), offset 0xfd8 the gpioperiphid4 , gpioperiphid5 , gpioperiphid6 , and gpioperiphid7 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register , used by software to identify the peripheral. gpio peripheral identification 6 (gpioperiphid6) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xfd8 t ype ro, reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid6 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio peripheral id register[23:16] 0x00 ro pid6 7:0 june 14, 2007 186 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 24: gpio peripheral identification 7 (gpioperiphid7), offset 0xfdc the gpioperiphid4 , gpioperiphid5 , gpioperiphid6 , and gpioperiphid7 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register , used by software to identify the peripheral. gpio peripheral identification 7 (gpioperiphid7) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xfdc t ype ro, reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid7 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio peripheral id register[31:24] 0x00 ro pid7 7:0 187 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 25: gpio peripheral identification 0 (gpioperiphid0), offset 0xfe0 the gpioperiphid0 , gpioperiphid1 , gpioperiphid2 , and gpioperiphid3 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register , used by software to identify the peripheral. gpio peripheral identification 0 (gpioperiphid0) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xfe0 t ype ro, reset 0x0x0000.0061 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio peripheral id register[7:0] can be used by software to identify the presence of this peripheral. 0x61 ro pid0 7:0 june 14, 2007 188 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 26: gpio peripheral identification 1(gpioperiphid1), offset 0xfe4 the gpioperiphid0 , gpioperiphid1 , gpioperiphid2 , and gpioperiphid3 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register , used by software to identify the peripheral. gpio peripheral identification 1 (gpioperiphid1) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xfe4 t ype ro, reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio peripheral id register[15:8] can be used by software to identify the presence of this peripheral. 0x00 ro pid1 7:0 189 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 27: gpio peripheral identification 2 (gpioperiphid2), offset 0xfe8 the gpioperiphid0 , gpioperiphid1 , gpioperiphid2 , and gpioperiphid3 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register , used by software to identify the peripheral. gpio peripheral identification 2 (gpioperiphid2) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xfe8 t ype ro, reset 0x0x0000.0018 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio peripheral id register[23:16] can be used by software to identify the presence of this peripheral. 0x18 ro pid2 7:0 june 14, 2007 190 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 28: gpio peripheral identification 3 (gpioperiphid3), offset 0xfec the gpioperiphid0 , gpioperiphid1 , gpioperiphid2 , and gpioperiphid3 registers can conceptually be treated as one 32-bit register; each register contains eight bits of the 32-bit register , used by software to identify the peripheral. gpio peripheral identification 3 (gpioperiphid3) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xfec t ype ro, reset 0x0x0000.0001 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio peripheral id register[31:24] can be used by software to identify the presence of this peripheral. 0x01 ro pid3 7:0 191 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 29: gpio primecell identification 0 (gpiopcellid0), offset 0xff0 the gpiopcellid0 , gpiopcellid1 , gpiopcellid2 , and gpiopcellid3 registers are four 8-bit wide registers, that can conceptually be treated as one 32-bit register . the register is used as a standard cross-peripheral identification system. gpio primecell identification 0 (gpiopcellid0) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xff0 t ype ro, reset 0x0x0000.000d 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio primecell id register[7:0] provides software a standard cross-peripheral identification system. 0x0d ro cid0 7:0 june 14, 2007 192 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 30: gpio primecell identification 1 (gpiopcellid1), offset 0xff4 the gpiopcellid0 , gpiopcellid1 , gpiopcellid2 , and gpiopcellid3 registers are four 8-bit wide registers, that can conceptually be treated as one 32-bit register . the register is used as a standard cross-peripheral identification system. gpio primecell identification 1 (gpiopcellid1) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xff4 t ype ro, reset 0x0x0000.00f0 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio primecell id register[15:8] provides software a standard cross-peripheral identification system. 0xf0 ro cid1 7:0 193 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 31: gpio primecell identification 2 (gpiopcellid2), offset 0xff8 the gpiopcellid0 , gpiopcellid1 , gpiopcellid2 , and gpiopcellid3 registers are four 8-bit wide registers, that can conceptually be treated as one 32-bit register . the register is used as a standard cross-peripheral identification system. gpio primecell identification 2 (gpiopcellid2) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xff8 t ype ro, reset 0x0x0000.0005 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio primecell id register[23:16] provides software a standard cross-peripheral identification system. 0x05 ro cid2 7:0 june 14, 2007 194 luminary micro confidential-advance product information general-purpose input/outputs (gpios)
register 32: gpio primecell identification 3 (gpiopcellid3), offset 0xffc the gpiopcellid0 , gpiopcellid1 , gpiopcellid2 , and gpiopcellid3 registers are four 8-bit wide registers, that can conceptually be treated as one 32-bit register . the register is used as a standard cross-peripheral identification system. gpio primecell identification 3 (gpiopcellid3) gpio port a base: 0x4000.4000 gpio port b base: 0x4000.5000 gpio port c base: 0x4000.6000 gpio port d base: 0x4000.7000 gpio port e base: 0x4002.4000 gpio port f base: 0x4002.5000 gpio port g base: 0x4002.6000 of fset 0xffc t ype ro, reset 0x0x0000.00b1 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 1 1 0 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gpio primecell id register[31:24] provides software a standard cross-peripheral identification system. 0xb1 ro cid3 7:0 195 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
10 general-purpose t imers gptm programmable timers can be used to count or time external events that drive the t imer input pins. the stellaris ? general-purpose t imer module (gptm) contains four gptm blocks (t imer0, t imer1, t imer 2, and t imer 3). each gptm block provides two 16-bit timer/counters (referred to as t imera and t imerb) that can be configured to operate independently as timers or event counters, or configured to operate as one 32-bit timer or one 32-bit real-t ime clock (r tc). t imers can also be used to trigger analog-to-digital (adc) conversions. the trigger signals from all of the general-purpose timers are ored together before reaching the adc module, so only one timer should be used to trigger adc events. note: t imer2 is an internal timer and can only be used to generate internal interrupts or trigger adc events. the general-purpose t imer module is one timing resource available on the stellaris ? microcontrollers. other timer resources include the system t imer (syst ick) (see system t imer (syst ick) on page 38 ). the following modes are supported: 32-bit t imer modes C programmable one-shot timer C programmable periodic timer C real-t ime clock using 32.768-khz input clock C software-controlled event stalling (excluding r tc mode) 16-bit t imer modes C general-purpose timer function with an 8-bit prescaler (for one-shot and periodic modes only) C programmable one-shot timer C programmable periodic timer C software-controlled event stalling 16-bit input capture modes C input edge count capture C input edge time capture 16-bit pwm mode C simple pwm mode with software-programmable output inversion of the pwm signal june 14, 2007 196 luminary micro confidential-advance product information general-purpose t imers
10.1 block diagram figure 10-1. gptm module block diagram 10.2 functional description the main components of each gptm block are two free-running 16-bit up/down counters (referred to as t imera and t imerb), two 16-bit match registers, two prescaler match registers, and two 16-bit load/initialization registers and their associated control functions. the exact functionality of each gptm is controlled by software and configured through the register interface. software configures the gptm using the gptm configuration (gptmcfg) register (see page 208 ), the gptm t imera mode (gptmt amr) register (see page 209 ), and the gptm t imerb mode (gptmtbmr) register (see page 210 ). when in one of the 32-bit modes, the timer can only act as a 32-bit timer . however , when configured in 16-bit mode, the gptm can have its two 16-bit timers configured in any combination of the 16-bit modes. 10.2.1 gptm reset conditions after reset has been applied to the gptm module, the module is in an inactive state, and all control registers are cleared and in their default states. counters t imera and t imerb are initialized to 0xffff , along with their corresponding load registers: the gptm t imera interval load (gptmt ailr) register (see page 219 ) and the gptm t imerb interval load (gptmtbilr) register (see page 220 ). the prescale counters are initialized to 0x00: the gptm t imera prescale (gptmt apr) register (see page 223 ) and the gptm t imerb prescale (gptmtbpr) register (see page 224 ). 10.2.2 32-bit t imer operating modes note: both the odd- and even-numbered ccp pins are used for 16-bit mode. only the even-numbered ccp pins are used for 32-bit mode. 197 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller t a comparator tb comparator gptmtbr gptmar clock / edge detect r tc divider clock / edge detect t imera interrupt t imerb interrupt system clock 0x0000 (down counter modes) 0x0000 (down counter modes) ccp (even) ccp (odd) en en t imera control gptmt apmr gptmt ailr gptmt ama tchr gptmt apr gptmt amr t imerb control gptmtbpmr gptmtbilr gptmtbma tchr gptmtbpr gptmtbmr interrupt / config gptmcfg gptmris gptmicr gptmmis gptmimr gptmctl
this section describes the three gptm 32-bit timer modes (one-shot, periodic, and r tc) and their configuration. the gptm is placed into 32-bit mode by writing a 0 (one-shot/periodic 32-bit timer mode) or a 1 (r tc mode) to the gptm configuration (gptmcfg) register . in both configurations, certain gptm registers are concatenated to form pseudo 32-bit registers. these registers include: gptm t imera interval load (gptmt ailr) register [15:0], see page 219 gptm t imerb interval load (gptmtbilr) register [15:0], see page 220 gptm t imera (gptmt ar) register [15:0], see page 227 gptm t imerb (gptmtbr) register [15:0], see page 228 in the 32-bit modes, the gptm translates a 32-bit write access to gptmt ailr into a write access to both gptmt ailr and gptmtbilr . the resulting word ordering for such a write operation is: gptmtbilr[15:0]:gptmtailr[15:0] likewise, a read access to gptmt ar returns the value: gptmtbr[15:0]:gptmtar[15:0] 10.2.2.1 32-bit one-shot/periodic t imer mode in 32-bit one-shot and periodic timer modes, the concatenated versions of the t imera and t imerb registers are configured as a 32-bit down-counter . the selection of one-shot or periodic mode is determined by the value written to the tamr field of the gptm t imera mode (gptmt amr) register (see page 209 ), and there is no need to write to the gptm t imerb mode (gptmtbmr) register . when software writes the taen bit in the gptm control (gptmctl) register (see page 211 ), the timer begins counting down from its preloaded value. once the 0x0000.0000 state is reached, the timer reloads its start value from the concatenated gptmt ailr on the next cycle. if configured to be a one-shot timer , the timer stops counting and clears the taen bit in the gptmctl register . if configured as a periodic timer , it continues counting. in addition to reloading the count value, the gptm generates interrupts and output triggers when it reaches the 0x0000000 state. the gptm sets the tatoris bit in the gptm raw interrupt status (gptmris) register (see page 215 ), and holds it until it is cleared by writing the gptm interrupt clear (gptmicr) register (see page 217 ). if the time-out interrupt is enabled in the gptm interrupt mask (gptimr) register (see page 213 ), the gptm also sets the tatomis bit in the gptm masked interrupt status (gptmmis) register (see page 216 ). the output trigger is a one-clock-cycle pulse that is asserted when the counter hits the 0x0000.0000 state, and deasserted on the following clock cycle. it is enabled by setting the taote bit in gptmctl , and can trigger soc-level events such as adc conversions. if software reloads the gptmt ailr register while the counter is running, the counter loads the new value on the next clock cycle and continues counting from the new value. if the tastall bit in the gptmctl register is asserted, the timer freezes counting until the signal is deasserted. 10.2.2.2 32-bit real-t ime clock t imer mode in real-t ime clock (r tc) mode, the concatenated versions of the t imera and t imerb registers are configured as a 32-bit up-counter . when r tc mode is selected for the first time, the counter is june 14, 2007 198 luminary micro confidential-advance product information general-purpose t imers
loaded with a value of 0x0000.0001. all subsequent load values must be written to the gptm t imera match (gptmt ama tchr) register (see page 221 ) by the controller . the input clock on the ccp0, ccp2 or ccp4 pins is required to be 32.768 khz in r tc mode. the clock signal is then divided down to a 1 hz rate and is passed along to the input of the 32-bit counter . when software writes the taen bit inthe gptmctl register , the counter starts counting up from its preloaded value of 0x0000.0001. when the current count value matches the preloaded value in the gptmt ama tchr register , it rolls over to a value of 0x0000.0000 and continues counting until either a hardware reset, or it is disabled by software (clearing the taen bit). when a match occurs, the gptm asserts the rtcris bit in gptmris . if the r tc interrupt is enabled in gptimr , the gptm also sets the rtcmis bit in gptmisr and generates a controller interrupt. the status flags are cleared by writing the rtccint bit in gptmicr . if the tastall and/or tbstall bits in the gptmctl register are set, the timer does not freeze if the rtcen bit is set in gptmctl . 10.2.3 16-bit t imer operating modes the gptm is placed into global 16-bit mode by writing a value of 0x4 to the gptm configuration (gptmcfg) register (see page 208 ). this section describes each of the gptm 16-bit modes of operation. t imera and t imerb have identical modes, so a single description is given using an n to reference both. 10.2.3.1 16-bit one-shot/periodic t imer mode in 16-bit one-shot and periodic timer modes, the timer is configured as a 16-bit down-counter with an optional 8-bit prescaler that ef fectively extends the counting range of the timer to 24 bits. the selection of one-shot or periodic mode is determined by the value written to the tnmr field of the gptmtnmr register . the optional prescaler is loaded into the gptm t imern prescale (gptmtnpr) register . when software writes the tnen bit in the gptmctl register , the timer begins counting down from its preloaded value. once the 0x0000 state is reached, the timer reloads its start value from gptmtnilr and gptmtnpr on the next cycle. if configured to be a one-shot timer , the timer stops counting and clears the tnen bit in the gptmctl register . if configured as a periodic timer , it continues counting. in addition to reloading the count value, the timer generates interrupts and output triggers when it reaches the 0x0000 state. the gptm sets the tntoris bit in the gptmris register , and holds it until it is cleared by writing the gptmicr register . if the time-out interrupt is enabled in gptimr , the gptm also sets the tntomis bit in gptmisr and generates a controller interrupt. the output trigger is a one-clock-cycle pulse that is asserted when the counter hits the 0x0000 state, and deasserted on the following clock cycle. it is enabled by setting the tnote bit in the gptmctl register , and can trigger soc-level events such as adc conversions. if software reloads the gptmt ailr register while the counter is running, the counter loads the new value on the next clock cycle and continues counting from the new value. if the tnstall bit in the gptmctl register is enabled, the timer freezes counting until the signal is deasserted. the following example shows a variety of configurations for a 16-bit free running timer while using the prescaler . all values assume a 50-mhz clock with t c=20 ns (clock period). 199 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
t able 10-1. 16-bit t imer w ith prescaler configurations units max t ime #clock (t c) a prescale ms 1.3107 1 00000000 ms 2.6214 2 00000001 ms 23.9321 3 00000010 -- -- -- ------------ ms 332.9229 254 1 1 1 1 1 100 ms 334.2336 255 1 1 1 1 1 1 10 ms 335.5443 256 1 1 1 1 1 1 1 1 a. t c is the clock period. 10.2.3.2 16-bit input edge count mode in edge count mode, the timer is configured as a down-counter capable of capturing three types of events: rising edge, falling edge, or both. t o place the timer in edge count mode, the tncmr bit of the gptmtnmr register must be set to 0. the type of edge that the timer counts is determined by the tnevent fields of the gptmctl register . during initialization, the gptm t imern match (gptmtnma tchr) register is configured so that the dif ference between the value in the gptmtnilr register and the gptmtnma tchr register equals the number of edge events that must be counted. when software writes the tnen bit in the gptm control (gptmctl) register , the timer is enabled for event capture. each input event on the ccp pin decrements the counter by 1 until the event count matches gptmtnma tchr . when the counts match, the gptm asserts the cnmris bit in the gptmris register (and the cnmmis bit, if the interrupt is not masked). the counter is then reloaded using the value in gptmtnilr , and stopped since the gptm automatically clears the tnen bit in the gptmctl register . once the event count has been reached, all further events are ignored until tnen is re-enabled by software. figure 10-2 on page 201 shows how input edge count mode works. in this case, the timer start value is set to gptmnilr =0x000a and the match value is set to gptmnma tchr =0x0006 so that four edge events are counted. the counter is configured to detect both edges of the input signal. note that the last two edges are not counted since the timer automatically clears the tnen bit after the current count matches the value in the gptmnmr register . june 14, 2007 200 luminary micro confidential-advance product information general-purpose t imers
figure 10-2. 16-bit input edge count mode example 10.2.3.3 16-bit input edge t ime mode note: the prescaler is not available in 16-bit input edge t ime mode. in edge t ime mode, the timer is configured as a free-running down-counter initialized to the value loaded in the gptmtnilr register (or 0xffff at reset). this mode allows for event capture of both rising and falling edges. the timer is placed into edge t ime mode by setting the tncmr bit in the gptmtnmr register , and the type of event that the timer captures is determined by the tnevent fields of the gptmcntl register . when software writes the tnen bit in the gptmctl register , the timer is enabled for event capture. when the selected input event is detected, the current tn counter value is captured in the gptmtnr register and is available to be read by the controller . the gptm then asserts the cneris bit (and the cnemis bit, if the interrupt is not masked). after an event has been captured, the timer does not stop counting. it continues to count until the tnen bit is cleared. when the timer reaches the 0x0000 state, it is reloaded with the value from the gptmnilr register . figure 10-3 on page 202 shows how input edge timing mode works. in the diagram, it is assumed that the start value of the timer is the default value of 0xffff , and the timer is configured to capture rising edge events. each time a rising edge event is detected, the current count value is loaded into the gptmtnr register , and is held there until another rising edge is detected (at which point the new count value is loaded into gptmtnr ). 201 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller 0x000a 0x0006 0x0007 0x0008 0x0009 input signal t imer stops, flags asserted t imer reload on next cycle ignored ignored count
figure 10-3. 16-bit input edge t ime mode example 10.2.3.4 16-bit pwm mode the gptm supports a simple pwm generation mode. in pwm mode, the timer is configured as a down-counter with a start value (and thus period) defined by gptmtnilr . pwm mode is enabled with the gptmtnmr register by setting the tnams bit to 0x1, the tncmr bit to 0x0, and the tnmr field to 0x2. when software writes the tnen bit in the gptmctl register , the counter begins counting down until it reaches the 0x0000 state. on the next counter cycle, the counter reloads its start value from gptmtnilr (and gptmtnpr if using a prescaler) and continues counting until disabled by software clearing the tnen bit in the gptmctl register . no interrupts or status bits are asserted in pwm mode. the output pwm signal asserts when the counter is at the value of the gptmtnilr register (its start state), and is deasserted when the counter value equals the value in the gptm t imern match register (gptmnma tchr) . software has the capability of inverting the output pwm signal by setting the tnpwml bit in the gptmctl register . figure 10-4 on page 203 shows how to generate an output pwm with a 1-ms period and a 66% duty cycle assuming a 50-mhz input clock and tnpwml =0 (duty cycle would be 33% for the tnpwml =1 configuration). for this example, the start value is gptmnirl =0xc350 and the match value is gptmnmr =0x41 1a. june 14, 2007 202 luminary micro confidential-advance product information general-purpose t imers gptmtnr=y input signal t ime count gptmtnr=x gptmtnr=z z x y 0xffff
figure 10-4. 16-bit pwm mode example 10.3 initialization and configuration t o use the general-purpose timers, the peripheral clock must be enabled by setting the timer0 , timer1 , timer2 , and timer3 bits in the rcgc1 register . this section shows module initialization and configuration examples for each of the supported timer modes. 10.3.1 32-bit one-shot/periodic t imer mode the gptm is configured for 32-bit one-shot and periodic modes by the following sequence: 1. ensure the timer is disabled (the taen bit in the gptmctl register is cleared) before making any changes. 2. w rite the gptm configuration register (gptmcfg) with a value of 0x0. 3. set the tamr field in the gptm t imera mode register (gptmt amr) : a. w rite a value of 0x1 for one-shot mode. b. w rite a value of 0x2 for periodic mode. 4. load the start value into the gptm t imera interval load register (gptmt ailr) . 5. if interrupts are required, set the tatoim bit in the gptm interrupt mask register (gptmimr) . 6. set the taen bit in the gptmctl register to enable the timer and start counting. 203 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller output signal t ime count gptmtnr=gptmnmr gptmtnr=gptmnmr 0xc350 0x41 1a tnpwml = 0 tnpwml = 1 tnen set
7. poll the tatoris bit in the gptmris register or wait for the interrupt to be generated (if enabled). in both cases, the status flags are cleared by writing a 1 to the tatocint bit of the gptm interrupt clear register (gptmicr) . in one-shot mode, the timer stops counting after 7 on page 204 . t o re-enable the timer , repeat the sequence. a timer configured in periodic mode does not stop counting after it times out. 10.3.2 32-bit real-t ime clock (rtc) mode t o use the r tc mode, the timer must have a 32.768-khz input signal on its ccp0, ccp2 or ccp4 pins. t o enable the r tc feature, follow these steps: 1. ensure the timer is disabled (the taen bit is cleared) before making any changes. 2. w rite the gptm configuration register (gptmcfg) with a value of 0x1. 3. w rite the desired match value to the gptm t imera match register (gptmt ama tchr) . 4. set/clear the rtcen bit in the gptm control register (gptmctl) as desired. 5. if interrupts are required, set the rtcim bit in the gptm interrupt mask register (gptmimr) . 6. set the taen bit in the gptmctl register to enable the timer and start counting. when the timer count equals the value in the gptmt ama tchr register , the counter is re-loaded with 0x0000.0000 and begins counting. if an interrupt is enabled, it does not have to be cleared. 10.3.3 16-bit one-shot/periodic t imer mode a timer is configured for 16-bit one-shot and periodic modes by the following sequence: 1. ensure the timer is disabled (the tnen bit is cleared) before making any changes. 2. w rite the gptm configuration register (gptmcfg) with a value of 0x4. 3. set the tnmr field in the gptm t imer mode (gptmtnmr) register: a. w rite a value of 0x1 for one-shot mode. b. w rite a value of 0x2 for periodic mode. 4. if a prescaler is to be used, write the prescale value to the gptm t imern prescale register (gptmtnpr) . 5. load the start value into the gptm t imer interval load register (gptmtnilr) . 6. if interrupts are required, set the tntoim bit in the gptm interrupt mask register (gptmimr) . 7. set the tnen bit in the gptm control register (gptmctl) to enable the timer and start counting. 8. poll the tntoris bit in the gptmris register or wait for the interrupt to be generated (if enabled). in both cases, the status flags are cleared by writing a 1 to the tntocint bit of the gptm interrupt clear register (gptmicr) . june 14, 2007 204 luminary micro confidential-advance product information general-purpose t imers
in one-shot mode, the timer stops counting after 8 on page 204 . t o re-enable the timer , repeat the sequence. a timer configured in periodic mode does not stop counting after it times out. 10.3.4 16-bit input edge count mode a timer is configured to input edge count mode by the following sequence: 1. ensure the timer is disabled (the tnen bit is cleared) before making any changes. 2. w rite the gptm configuration (gptmcfg) register with a value of 0x4. 3. in the gptm t imer mode (gptmtnmr) register , write the tncmr field to 0x0 and the tnmr field to 0x3. 4. configure the type of event(s) that the timer captures by writing the tnevent field of the gptm control (gptmctl) register . 5. load the timer start value into the gptm t imern interval load (gptmtnilr) register . 6. load the desired event count into the gptm t imern match (gptmtnma tchr) register . 7. if interrupts are required, set the cnmim bit in the gptm interrupt mask (gptmimr) register . 8. set the tnen bit in the gptmctl register to enable the timer and begin waiting for edge events. 9. poll the cnmris bit in the gptmris register or wait for the interrupt to be generated (if enabled). in both cases, the status flags are cleared by writing a 1 to the cnmcint bit of the gptm interrupt clear (gptmicr) register . in input edge count mode, the timer stops after the desired number of edge events has been detected. t o re-enable the timer , ensure that the tnen bit is cleared and repeat steps 4 on page 205 - 9 on page 205 . 10.3.5 16-bit input edge t iming mode a timer is configured to input edge t iming mode by the following sequence: 1. ensure the timer is disabled (the tnen bit is cleared) before making any changes. 2. w rite the gptm configuration (gptmcfg) register with a value of 0x4. 3. in the gptm t imer mode (gptmtnmr) register , write the tncmr field to 0x1 and the tnmr field to 0x3. 4. configure the type of event that the timer captures by writing the tnevent field of the gptm control (gptmctl) register . 5. load the timer start value into the gptm t imern interval load (gptmtnilr) register . 6. if interrupts are required, set the cneim bit in the gptm interrupt mask (gptmimr) register . 7. set the tnen bit in the gptm control (gptmctl) register to enable the timer and start counting. 8. poll the cneris bit in the gptmris register or wait for the interrupt to be generated (if enabled). in both cases, the status flags are cleared by writing a 1 to the cnecint bit of the gptm 205 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
interrupt clear (gptmicr) register . the time at which the event happened can be obtained by reading the gptm t imern (gptmtnr) register . in input edge t iming mode, the timer continues running after an edge event has been detected, but the timer interval can be changed at any time by writing the gptmtnilr register . the change takes ef fect at the next cycle after the write. 10.3.6 16-bit pwm mode a timer is configured to pwm mode using the following sequence: 1. ensure the timer is disabled (the tnen bit is cleared) before making any changes. 2. w rite the gptm configuration (gptmcfg) register with a value of 0x4. 3. in the gptm t imer mode (gptmtnmr) register , set the tnams bit to 0x1, the tncmr bit to 0x0, and the tnmr field to 0x2. 4. configure the output state of the pwm signal (whether or not it is inverted) in the tnevent field of the gptm control (gptmctl) register . 5. load the timer start value into the gptm t imern interval load (gptmtnilr) register . 6. load the gptm t imern match (gptmtnma tchr) register with the desired value. 7. set the tnen bit in the gptm control (gptmctl) register to enable the timer and begin generation of the output pwm signal. in pwm t iming mode, the timer continues running after the pwm signal has been generated. the pwm period can be adjusted at any time by writing the gptmtnilr register , and the change takes ef fect at the next cycle after the write. 10.4 register map t able 10-2 on page 206 lists the gptm registers. the of fset listed is a hexadecimal increment to the register s address, relative to that timer s base address: t imer0: 0x4003.0000 0x4003.0000 t imer1: 0x4003.1000 0x4003.1000 t imer2: 0x4003.2000 0x4003.2000 t imer3: 0x4003.3000 0x4003.3000 t able 10-2. t imers register map see page description reset t ype name offset 208 gptm configuration 0x0x0000.0000 r/w gptmcfg 0x000 209 gptm t imera mode 0x0x0000.0000 r/w gptmt amr 0x004 210 gptm t imerb mode 0x0x0000.0000 r/w gptmtbmr 0x008 211 gptm control 0x0x0000.0000 r/w gptmctl 0x00c june 14, 2007 206 luminary micro confidential-advance product information general-purpose t imers
see page description reset t ype name offset 213 gptm interrupt mask 0x0x0000.0000 r/w gptmimr 0x018 215 gptm raw interrupt status 0x0x0000.0000 ro gptmris 0x01c 216 gptm masked interrupt status 0x0x0000.0000 ro gptmmis 0x020 217 gptm interrupt clear 0x0x0000.0000 w1c gptmicr 0x024 219 gptm t imera interval load 0x0000.ffff (16-bit mode) 0xffff .ffff (32-bit mode) r/w gptmt ailr 0x028 220 gptm t imerb interval load 0x0000.ffff r/w gptmtbilr 0x02c 221 gptm t imera match 0x0000.ffff (16-bit mode) 0xffff .ffff (32-bit mode) r/w gptmt ama tchr 0x030 222 gptm t imerb match 0x0000.ffff r/w gptmtbma tchr 0x034 223 gptm t imera prescale 0x0000.0000 r/w gptmt apr 0x038 224 gptm t imerb prescale 0x0000.0000 r/w gptmtbpr 0x03c 225 gptm t imera prescale match 0x0000.0000 r/w gptmt apmr 0x040 226 gptm t imerb prescale match 0x0000.0000 r/w gptmtbpmr 0x044 227 gptm t imera 0x0000.ffff (16-bit mode) 0xffff .ffff (32-bit mode) ro gptmt ar 0x048 228 gptm t imerb 0x0000.ffff ro gptmtbr 0x04c 10.5 register descriptions the remainder of this section lists and describes the gptm registers, in numerical order by address of fset. 207 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1: gptm configuration (gptmcfg), offset 0x000 this register configures the global operation of the gptm module. the value written to this register determines whether the gptm is in 32- or 16-bit mode. gptm configuration (gptmcfg) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x000 t ype r/w , reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 gptmcfg reserved r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:3 gptm configuration 0x0: 32-bit timer configuration. 0x1: 32-bit real-time clock (r tc) counter configuration. 0x2: reserved. 0x3: reserved. 0x4-0x7: 16-bit timer configuration, function is controlled by bits 1:0 of gptmt amr and gptmtbmr . 0 r/w gptmcfg 2:0 june 14, 2007 208 luminary micro confidential-advance product information general-purpose t imers
register 2: gptm t imera mode (gptmt amr), offset 0x004 this register configures the gptm based on the configuration selected in the gptmcfg register . when in 16-bit pwm mode, set the taams bit to 0x1, the tacmr bit to 0x0, and the tamr field to 0x2. gptm t imera mode (gptmt amr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x004 t ype r/w , reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t amr t acmr t aams reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 gptm t imera alternate mode select 0: capture mode is enabled. 1: pwm mode is enabled. note: t o enable pwm mode, you must also clear the tacmr bit and set the tamr field to 0x2. 0 r/w t aams 3 gptm t imera capture mode 0: edge-count mode. 1: edge-t ime mode. 0 r/w t acmr 2 gptm t imera mode 0x0: reserved. 0x1: one-shot t imer mode. 0x2: periodic t imer mode. 0x3: capture mode. the t imer mode is based on the timer configuration defined by bits 2:0 in the gptmcfg register (16-or 32-bit). in 16-bit timer configuration, tamr controls the 16-bit timer modes for t imera. in 32-bit timer configuration, this register controls the mode and the contents of gptmtbmr are ignored. 0 r/w t amr 1:0 209 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: gptm t imerb mode (gptmtbmr), offset 0x008 this register configures the gptm based on the configuration selected in the gptmcfg register . when in 16-bit pwm mode, set the tbams bit to 0x1, the tbcmr bit to 0x0, and the tbmr field to 0x2. gptm t imerb mode (gptmtbmr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x008 t ype r/w , reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tbmr tbcmr tbams reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 gptm t imerb alternate mode select 0: capture mode is enabled. 1: pwm mode is enabled. note: t o enable pwm mode, you must also clear the tbcmr bit and set the tbmr field to 0x2. 0 r/w tbams 3 gptm t imerb capture mode 0: edge-count mode. 1: edge-t ime mode. 0 r/w tbcmr 2 gptm t imerb mode 0x0: reserved. 0x1: one-shot t imer mode. 0x2: periodic t imer mode. 0x3: capture mode. the timer mode is based on the timer configuration defined by bits 2:0 in the gptmcfg register . in 16-bit timer configuration, these bits control the 16-bit timer modes for t imerb. in 32-bit timer configuration, this register s contents are ignored and gptmt amr is used. 0 r/w tbmr 1:0 june 14, 2007 210 luminary micro confidential-advance product information general-purpose t imers
register 4: gptm control (gptmctl), offset 0x00c this register is used alongside the gptmcfg and gmtmtnmr registers to fine-tune the timer configuration, and to enable other features such as timer stall and the output trigger . the output trigger can be used to initiate transfers on the adc module. gptm control (gptmctl) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x00c t ype r/w , reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t aen t ast all t aevent r tcen t aote t apwml reserved tben tbst all tbevent reserved tbote tbpwml reserved r/w r/w r/w r/w r/w r/w r/w ro r/w r/w r/w r/w ro r/w r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:15 gptm t imerb pwm output level 0: output is unaf fected. 1: output is inverted. 0 r/w tbpwml 14 gptm t imerb output t rigger enable 0: the output t imerb trigger is disabled. 1: the output t imerb trigger is enabled. 0 r/w tbote 13 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 12 gptm t imerb event mode 00: positive edge. 01: negative edge. 10: reserved. 1 1: both edges. 0 r/w tbevent 1 1:10 gptm t imerb stall enable 0: t imerb stalling is disabled. 1: t imerb stalling is enabled. 0 r/w tbst all 9 21 1 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field gptm t imerb enable 0: t imerb is disabled. 1: t imerb is enabled and begins counting or the capture logic is enabled based on the gptmcfg register . 0 r/w tben 8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7 gptm t imera pwm output level 0: output is unaf fected. 1: output is inverted. 0 r/w t apwml 6 gptm t imera output t rigger enable 0: the output t imera trigger is disabled. 1: the output t imera trigger is enabled. 0 r/w t aote 5 gptm r tc enable 0: r tc counting is disabled. 1: r tc counting is enabled. 0 r/w r tcen 4 gptm t imera event mode 00: positive edge. 01: negative edge. 10: reserved. 1 1: both edges. 0 r/w t aevent 3:2 gptm t imera stall enable 0: t imera stalling is disabled. 1: t imera stalling is enabled. 0 r/w t ast all 1 gptm t imera enable 0: t imera is disabled. 1: t imera is enabled and begins counting or the capture logic is enabled based on the gptmcfg register . 0 r/w t aen 0 june 14, 2007 212 luminary micro confidential-advance product information general-purpose t imers
register 5: gptm interrupt mask (gptmimr), offset 0x018 this register allows software to enable/disable gptm controller-level interrupts. w riting a 1 enables the interrupt, while writing a 0 disables it. gptm interrupt mask (gptmimr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x018 t ype r/w , reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t a t oim camim caeim r tcim reserved tbt oim cbmim cbeim reserved r/w r/w r/w r/w ro ro ro ro r/w r/w r/w ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 1 gptm captureb event interrupt mask 0: interrupt is disabled. 1: interrupt is enabled. 0 r/w cbeim 10 gptm captureb match interrupt mask 0: interrupt is disabled. 1: interrupt is enabled. 0 r/w cbmim 9 gptm t imerb t ime-out interrupt mask 0: interrupt is disabled. 1: interrupt is enabled. 0 r/w tbt oim 8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7:4 gptm r tc interrupt mask 0: interrupt is disabled. 1: interrupt is enabled. 0 r/w r tcim 3 gptm capturea event interrupt mask 0: interrupt is disabled. 1: interrupt is enabled. 0 r/w caeim 2 213 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field gptm capturea match interrupt mask 0: interrupt is disabled. 1: interrupt is enabled. 0 r/w camim 1 gptm t imera t ime-out interrupt mask 0: interrupt is disabled. 1: interrupt is enabled. 0 r/w t a t oim 0 june 14, 2007 214 luminary micro confidential-advance product information general-purpose t imers
register 6: gptm raw interrupt status (gptmris), offset 0x01c this register shows the state of the gptm's internal interrupt signal. these bits are set whether or not the interrupt is masked in the gptmimr register . each bit can be cleared by writing a 1 to its corresponding bit in gptmicr . gptm raw interrupt status (gptmris) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x01c t ype ro, reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t a t oris camris caeris r tcris reserved tbt oris cbmris cberis reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 1 gptm captureb event raw interrupt this is the captureb event interrupt status prior to masking. 0 ro cberis 10 gptm captureb match raw interrupt this is the captureb match interrupt status prior to masking. 0 ro cbmris 9 gptm t imerb t ime-out raw interrupt this is the t imerb time-out interrupt status prior to masking. 0 ro tbt oris 8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7:4 gptm r tc raw interrupt this is the r tc event interrupt status prior to masking. 0 ro r tcris 3 gptm capturea event raw interrupt this is the capturea event interrupt status prior to masking. 0 ro caeris 2 gptm capturea match raw interrupt this is the capturea match interrupt status prior to masking. 0 ro camris 1 gptm t imera t ime-out raw interrupt this the t imera time-out interrupt status prior to masking. 0 ro t a t oris 0 215 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: gptm masked interrupt status (gptmmis), offset 0x020 this register show the state of the gptm's controller-level interrupt. if an interrupt is unmasked in gptmimr , and there is an event that causes the interrupt to be asserted, the corresponding bit is set in this register . all bits are cleared by writing a 1 to the corresponding bit in gptmicr . gptm masked interrupt status (gptmmis) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x020 t ype ro, reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t a t omis cammis caemis r tcmis reserved tbt omis cbmmis cbemis reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 1 gptm captureb event masked interrupt this is the captureb event interrupt status after masking. 0 ro cbemis 10 gptm captureb match masked interrupt this is the captureb match interrupt status after masking. 0 ro cbmmis 9 gptm t imerb t ime-out masked interrupt this is the t imerb time-out interrupt status after masking. 0 ro tbt omis 8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7:4 gptm r tc masked interrupt this is the r tc event interrupt status after masking. 0 ro r tcmis 3 gptm capturea event masked interrupt this is the capturea event interrupt status after masking. 0 ro caemis 2 gptm capturea match masked interrupt this is the capturea match interrupt status after masking. 0 ro cammis 1 gptm t imera t ime-out masked interrupt this is the t imera time-out interrupt status after masking. 0 ro t a t omis 0 june 14, 2007 216 luminary micro confidential-advance product information general-purpose t imers
register 8: gptm interrupt clear (gptmicr), offset 0x024 this register is used to clear the status bits in the gptmris and gptmmis registers. w riting a 1 to a bit clears the corresponding bit in the gptmris and gptmmis registers. gptm interrupt clear (gptmicr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x024 t ype w1c, reset 0x0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t a t ocint camcint caecint r tccint reserved tbt ocint cbmcint cbecint reserved w1c w1c w1c w1c ro ro ro ro w1c w1c w1c ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 1 gptm captureb event interrupt clear 0: the interrupt is unaf fected. 1: the interrupt is cleared. 0 w1c cbecint 10 gptm captureb match interrupt clear 0: the interrupt is unaf fected. 1: the interrupt is cleared. 0 w1c cbmcint 9 gptm t imerb t ime-out interrupt clear 0: the interrupt is unaf fected. 1: the interrupt is cleared. 0 w1c tbt ocint 8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7:4 gptm r tc interrupt clear 0: the interrupt is unaf fected. 1: the interrupt is cleared. 0 w1c r tccint 3 gptm capturea event interrupt clear 0: the interrupt is unaf fected. 1: the interrupt is cleared. 0 w1c caecint 2 gptm capturea match raw interrupt this is the capturea match interrupt status after masking. 0 w1c camcint 1 217 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field gptm t imera t ime-out raw interrupt 0: the interrupt is unaf fected. 1: the interrupt is cleared. 0 w1c t a t ocint 0 june 14, 2007 218 luminary micro confidential-advance product information general-purpose t imers
register 9: gptm t imera interval load (gptmt ailr), offset 0x028 this register is used to load the starting count value into the timer . when gptm is configured to one of the 32-bit modes, gptmt ailr appears as a 32-bit register (the upper 16-bits correspond to the contents of the gptm t imerb interval load (gptmtbilr) register). in 16-bit mode, the upper 16 bits of this register read as 0s and have no ef fect on the state of gptmtbilr . gptm t imera interval load (gptmt ailr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x028 t ype r/w , reset 0x0000.ffff (16-bit mode) and 0xffff .ffff (32-bit mode) 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 t ailrh r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 1 1 1 1 0 1 1 1 1 0 1 0 1 1 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t ailrl r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field gptm t imera interval load register high when configured for 32-bit mode via the gptmcfg register , the gptm t imerb interval load (gptmtbilr) register loads this value on a write. a read returns the current value of gptmtbilr . in 16-bit mode, this field reads as 0 and does not have an ef fect on the state of gptmtbilr . 0xffff (32-bit mode) 0x0000 (16-bit mode) r/w t ailrh 31:16 gptm t imera interval load register low for both 16- and 32-bit modes, writing this field loads the counter for t imera. a read returns the current value of gptmt ailr . 0xffff r/w t ailrl 15:0 219 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 10: gptm t imerb interval load (gptmtbilr), offset 0x02c this register is used to load the starting count value into t imerb. when the gptm is configured to a 32-bit mode, gptmtbilr returns the current value of t imerb and ignores writes. gptm t imerb interval load (gptmtbilr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x02c t ype r/w , reset 0x0000.ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tbilrl r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 gptm t imerb interval load register when the gptm is not configured as a 32-bit timer , a write to this field updates gptmtbilr . in 32-bit mode, writes are ignored, and reads return the current value of gptmtbilr . 0xffff r/w tbilrl 15:0 june 14, 2007 220 luminary micro confidential-advance product information general-purpose t imers
register 1 1: gptm t imera match (gptmt ama tchr), offset 0x030 this register is used in 32-bit real-t ime clock mode and 16-bit pwm and input edge count modes. gptm t imera match (gptmt ama tchr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x030 t ype r/w , reset 0x0000.ffff (16-bit mode) and 0xffff .ffff (32-bit mode) 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 t amrh r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 1 1 1 1 0 1 1 1 1 0 1 0 1 1 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t amrl r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field gptm t imera match register high when configured for 32-bit real-t ime clock (r tc) mode via the gptmcfg register , this value is compared to the upper half of gptmt ar , to determine match events. in 16-bit mode, this field reads as 0 and does not have an ef fect on the state of gptmtbma tchr . 0xffff (32-bit mode) 0x0000 (16-bit mode) r/w t amrh 31:16 gptm t imera match register low when configured for 32-bit real-t ime clock (r tc) mode via the gptmcfg register , this value is compared to the lower half of gptmt ar , to determine match events. when configured for pwm mode, this value along with gptmt ailr , determines the duty cycle of the output pwm signal. when configured for edge count mode, this value along with gptmt ailr , determines how many edge events are counted. the total number of edge events counted is equal to the value in gptmt ailr minus this value. 0xffff r/w t amrl 15:0 221 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 12: gptm t imerb match (gptmtbma tchr), offset 0x034 this register is used in 32-bit real-t ime clock mode and 16-bit pwm and input edge count modes. gptm t imerb match (gptmtbma tchr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x034 t ype r/w , reset 0x0000.ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tbmrl r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 gptm t imerb match register low when configured for pwm mode, this value along with gptmtbilr , determines the duty cycle of the output pwm signal. when configured for edge count mode, this value along with gptmtbilr , determines how many edge events are counted. the total number of edge events counted is equal to the value in gptmtbilr minus this value. 0xffff r/w tbmrl 15:0 june 14, 2007 222 luminary micro confidential-advance product information general-purpose t imers
register 13: gptm t imera prescale (gptmt apr), offset 0x038 this register allows software to extend the range of the 16-bit timers when operating in one-shot or periodic mode. gptm t imera prescale (gptmt apr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x038 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t apsr reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gptm t imera prescale the register loads this value on a write. a read returns the current value of the register . refer to t able 10-1 on page 200 for more details and an example. 0 r/w t apsr 7:0 223 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 14: gptm t imerb prescale (gptmtbpr), offset 0x03c this register allows software to extend the range of the 16-bit timers when operating in one-shot or periodic mode. gptm t imerb prescale (gptmtbpr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x03c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tbpsr reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gptm t imerb prescale the register loads this value on a write. a read returns the current value of this register . refer to t able 10-1 on page 200 for more details and an example. 0 r/w tbpsr 7:0 june 14, 2007 224 luminary micro confidential-advance product information general-purpose t imers
register 15: gptm t imera prescale match (gptmt apmr), offset 0x040 this register ef fectively extends the range of gptmt ama tchr to 24 bits when operating in 16-bit one-shot or periodic mode. gptm t imera prescale match (gptmt apmr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x040 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t apsmr reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gptm t imera prescale match this value is used alongside gptmt ama tchr to detect timer match events while using a prescaler . 0 r/w t apsmr 7:0 225 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 16: gptm t imerb prescale match (gptmtbpmr), offset 0x044 this register ef fectively extends the range of gptmtbma tchr to 24 bits when operating in 16-bit one-shot or periodic mode. gptm t imerb prescale match (gptmtbpmr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x044 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tbpsmr reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 gptm t imerb prescale match this value is used alongside gptmtbma tchr to detect timer match events while using a prescaler . 0 r/w tbpsmr 7:0 june 14, 2007 226 luminary micro confidential-advance product information general-purpose t imers
register 17: gptm t imera (gptmt ar), offset 0x048 this register shows the current value of the t imera counter in all cases except for input edge count mode. when in this mode, this register contains the time at which the last edge event took place. gptm t imera (gptmt ar) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x048 t ype ro, reset 0x0000.ffff (16-bit mode) and 0xffff .ffff (32-bit mode) 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 t arh ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 1 1 1 1 0 1 1 1 1 0 1 0 1 1 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 t arl ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field gptm t imera register high if the gptmcfg is in a 32-bit mode, t imerb value is read. if the gptmcfg is in a 16-bit mode, this is read as zero. 0xffff (32-bit mode) 0x0000 (16-bit mode) ro t arh 31:16 gptm t imera register low a read returns the current value of the gptm t imera count register , except in input edge count mode, when it returns the timestamp from the last edge event. 0xffff ro t arl 15:0 227 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 18: gptm t imerb (gptmtbr), offset 0x04c this register shows the current value of the t imerb counter in all cases except for input edge count mode. when in this mode, this register contains the time at which the last edge event took place. gptm t imerb (gptmtbr) t imer0 base: 0x4003.0000 t imer1 base: 0x4003.1000 t imer2 base: 0x4003.2000 t imer3 base: 0x4003.3000 of fset 0x04c t ype ro, reset 0x0000.ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tbrl ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 gptm t imerb a read returns the current value of the gptm t imerb count register , except in input edge count mode, when it returns the timestamp from the last edge event. 0xffff ro tbrl 15:0 june 14, 2007 228 luminary micro confidential-advance product information general-purpose t imers
1 1 w atchdog t imer wdt a watchdog timer can generate nonmaskable interrupts (nmis) or a reset when a time-out value is reached. the watchdog timer is used to regain control when a system has failed due to a software error or due to the failure of an external device to respond in the expected way . the stellaris ? w atchdog t imer module consists of a 32-bit down counter , a programmable load register , interrupt generation logic, a locking register , and user-enabled stalling. the w atchdog t imer can be configured to generate an interrupt to the controller on its first time-out, and to generate a reset signal on its second time-out. once the w atchdog t imer has been configured, the lock register can be written to prevent the timer configuration from being inadvertently altered. 1 1.1 block diagram figure 1 1-1. wdt module block diagram 1 1.2 functional description the w atchdog t imer module consists of a 32-bit down counter , a programmable load register , interrupt generation logic, and a locking register . once the w atchdog t imer has been configured, 229 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller control / clock / interrupt generation wdtctl wdticr wdtris wdtmis wdtlock wdttest wdtload wdtv alue comparator 32-bit down counter 0x00000000 interrupt system clock identification registers wdtpcellid 0 wdtperiphid 0 wdtperiphid 4 wdtpcellid 1 wdtperiphid 1 wdtperiphid 5 wdtpcellid 2 wdtperiphid 2 wdtperiphid 6 wdtpcellid 3 wdtperiphid 3 wdtperiphid 7
the w atchdog t imer lock (wdtlock) register is written, which prevents the timer configuration from being inadvertently altered by software. the w atchdog t imer module generates the first time-out signal when the 32-bit counter reaches the zero state after being enabled; enabling the counter also enables the watchdog timer interrupt. after the first time-out event, the 32-bit counter is re-loaded with the value of the w atchdog t imer load (wdtload) register , and the timer resumes counting down from that value. if the timer counts down to its zero state again before the first time-out interrupt is cleared, and the reset signal has been enabled (via the watchdogresetenable function), the w atchdog timer asserts its reset signal to the system. if the interrupt is cleared before the 32-bit counter reaches its second time-out, the 32-bit counter is loaded with the value in the wdtload register , and counting resumes from that value. if wdtload is written with a new value while the w atchdog t imer counter is counting, then the counter is loaded with the new value and continues counting. w riting to wdtload does not clear an active interrupt. an interrupt must be specifically cleared by writing to the w atchdog interrupt clear (wdticr) register . the w atchdog module interrupt and reset generation can be enabled or disabled as required. when the interrupt is re-enabled, the 32-bit counter is preloaded with the load register value and not its last state. 1 1.3 initialization and configuration t o use the wdt , its peripheral clock must be enabled by setting the wdt bit in the rcgc0 register . the w atchdog t imer is configured using the following sequence: 1. load the wdtload register with the desired timer load value. 2. if the w atchdog is configured to trigger system resets, set the resen bit in the wdtctl register . 3. set the inten bit in the wdtctl register to enable the w atchdog and lock the control register . if software requires that all of the watchdog registers are locked, the w atchdog t imer module can be fully locked by writing any value to the wdtlock register . t o unlock the w atchdog t imer , write a value of 0x1acce551. 1 1.4 register map t able 1 1-1 on page 230 lists the w atchdog registers. the of fset listed is a hexadecimal increment to the register s address, relative to the w atchdog t imer base address of 0x4000.0000. t able 1 1-1. w atchdog t imer register map see page description reset t ype name offset 232 w atchdog load 0xffff .ffff r/w wdtload 0x000 233 w atchdog v alue 0xffff .ffff ro wdtv alue 0x004 234 w atchdog control 0x0000.0000 r/w wdtctl 0x008 235 w atchdog interrupt clear - wo wdticr 0x00c 236 w atchdog raw interrupt status 0x0000.0000 ro wdtris 0x010 june 14, 2007 230 luminary micro confidential-advance product information w atchdog t imer
see page description reset t ype name offset 237 w atchdog masked interrupt status 0x0000.0000 ro wdtmis 0x014 238 w atchdog t est 0x0000.0000 r/w wdttest 0x418 239 w atchdog lock 0x0000.0000 r/w wdtlock 0xc00 240 w atchdog peripheral identification 4 0x0000.0000 ro wdtperiphid4 0xfd0 241 w atchdog peripheral identification 5 0x0000.0000 ro wdtperiphid5 0xfd4 242 w atchdog peripheral identification 6 0x0000.0000 ro wdtperiphid6 0xfd8 243 w atchdog peripheral identification 7 0x0000.0000 ro wdtperiphid7 0xfdc 244 w atchdog peripheral identification 0 0x0000.0005 ro wdtperiphid0 0xfe0 245 w atchdog peripheral identification 1 0x0000.0018 ro wdtperiphid1 0xfe4 246 w atchdog peripheral identification 2 0x0000.0018 ro wdtperiphid2 0xfe8 247 w atchdog peripheral identification 3 0x0000.0001 ro wdtperiphid3 0xfec 248 w atchdog primecell identification 0 0x0000.000d ro wdtpcellid0 0xff0 249 w atchdog primecell identification 1 0x0000.00f0 ro wdtpcellid1 0xff4 250 w atchdog primecell identification 2 0x0000.0005 ro wdtpcellid2 0xff8 251 w atchdog primecell identification 3 0x0000.00b1 ro wdtpcellid3 0xffc 1 1.5 register descriptions the remainder of this section lists and describes the wdt registers, in numerical order by address of fset. 231 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1: w atchdog load (wdtload), offset 0x000 this register is the 32-bit interval value used by the 32-bit counter . when this register is written, the value is immediately loaded and the counter restarts counting down from the new value. if the wdtload register is loaded with 0x0000.0000, an interrupt is immediately generated. w atchdog load (wdtload) base 0x4000.0000 of fset 0x000 t ype r/w , reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 wdtload r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 wdtload r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field w atchdog load v alue 0xffff .ffff r/w wdtload 31:0 june 14, 2007 232 luminary micro confidential-advance product information w atchdog t imer
register 2: w atchdog v alue (wdtv alue), offset 0x004 this register contains the current count value of the timer . w atchdog v alue (wdtv alue) base 0x4000.0000 of fset 0x004 t ype ro, reset 0xffff .ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 wdtv alue ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 wdtv alue ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reset description reset t ype name bit/field w atchdog v alue current value of the 32-bit down counter . 0xffff .ffff ro wdtv alue 31:0 233 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: w atchdog control (wdtctl), offset 0x008 this register is the watchdog control register . the watchdog timer can be configured to generate a reset signal (on second time-out) or an interrupt on time-out. when the watchdog interrupt has been enabled, all subsequent writes to the control register are ignored. the only mechanism that can re-enable writes is a hardware reset. w atchdog control (wdtctl) base 0x4000.0000 of fset 0x008 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 inten resen reserved r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:2 w atchdog reset enable 0: disabled. 1: enable the w atchdog module reset output. 0 r/w resen 1 w atchdog interrupt enable 0: interrupt event disabled (once this bit is set, it can only be cleared by a hardware reset). 1: interrupt event enabled. once enabled, all writes are ignored. 0 r/w inten 0 june 14, 2007 234 luminary micro confidential-advance product information w atchdog t imer
register 4: w atchdog interrupt clear (wdticr), offset 0x00c this register is the interrupt clear register . a write of any value to this register clears the w atchdog interrupt and reloads the 32-bit counter from the wdtload register . v alue for a read or reset is indeterminate. w atchdog interrupt clear (wdticr) base 0x4000.0000 of fset 0x00c t ype wo, reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 wdtintclr wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo t ype - - - - - - - - - - - - - - - - reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 wdtintclr wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo t ype - - - - - - - - - - - - - - - - reset description reset t ype name bit/field w atchdog interrupt clear - wo wdtintclr 31:0 235 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: w atchdog raw interrupt status (wdtris), offset 0x010 this register is the raw interrupt status register . w atchdog interrupt events can be monitored via this register if the controller interrupt is masked. w atchdog raw interrupt status (wdtris) base 0x4000.0000 of fset 0x010 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 wdtris reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 w atchdog raw interrupt status gives the raw interrupt state (prior to masking) of wdtintr . 0 ro wdtris 0 june 14, 2007 236 luminary micro confidential-advance product information w atchdog t imer
register 6: w atchdog masked interrupt status (wdtmis), offset 0x014 this register is the masked interrupt status register . the value of this register is the logical and of the raw interrupt bit and the w atchdog interrupt enable bit. w atchdog masked interrupt status (wdtmis) base 0x4000.0000 of fset 0x014 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 wdtmis reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 w atchdog masked interrupt status gives the masked interrupt state (after masking) of the wdtintr interrupt. 0 ro wdtmis 0 237 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: w atchdog t est (wdttest), offset 0x418 this register provides user-enabled stalling when the microcontroller asserts the cpu halt flag during debug. w atchdog t est (wdttest) base 0x4000.0000 of fset 0x418 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved st all reserved ro ro ro ro ro ro ro ro r/w ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:9 w atchdog stall enable when set to 1, if the stellaris ? microcontroller is stopped with a debugger , the watchdog timer stops counting. once the microcontroller is restarted, the watchdog timer resumes counting. 0 r/w st all 8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7:0 june 14, 2007 238 luminary micro confidential-advance product information w atchdog t imer
register 8: w atchdog lock (wdtlock), offset 0xc00 w riting 0x1acce551 to the wdtlock register enables write access to all other registers. w riting any other value to the wdtlock register re-enables the locked state for register writes to all the other registers. reading the wdtlock register returns the lock status rather than the 32-bit value written. therefore, when write accesses are disabled, reading the wdtlock register returns 0x0000.0001 (when locked; otherwise, the returned value is 0x0000.0000 (unlocked)). w atchdog lock (wdtlock) base 0x4000.0000 of fset 0xc00 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 wdtlock r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 wdtlock r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field w atchdog lock a write of the value 0x1acce551 unlocks the watchdog registers for write access. a write of any other value reapplies the lock, preventing any register updates. a read of this register returns the following values: locked: 0x0000.0001 unlocked: 0x0000.0000 0x0000 r/w wdtlock 31:0 239 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 9: w atchdog peripheral identification 4 (wdtperiphid4), offset 0xfd0 the wdtperiphidn registers are hard-coded and the fields within the register determine the reset value. w atchdog peripheral identification 4 (wdtperiphid4) base 0x4000.0000 of fset 0xfd0 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid4 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 wdt peripheral id register[7:0] 0x00 ro pid4 7:0 june 14, 2007 240 luminary micro confidential-advance product information w atchdog t imer
register 10: w atchdog peripheral identification 5 (wdtperiphid5), offset 0xfd4 the wdtperiphidn registers are hard-coded and the fields within the register determine the reset value. w atchdog peripheral identification 5 (wdtperiphid5) base 0x4000.0000 of fset 0xfd4 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid5 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 wdt peripheral id register[15:8] 0x00 ro pid5 7:0 241 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1 1: w atchdog peripheral identification 6 (wdtperiphid6), offset 0xfd8 the wdtperiphidn registers are hard-coded and the fields within the register determine the reset value. w atchdog peripheral identification 6 (wdtperiphid6) base 0x4000.0000 of fset 0xfd8 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid6 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 wdt peripheral id register[23:16] 0x00 ro pid6 7:0 june 14, 2007 242 luminary micro confidential-advance product information w atchdog t imer
register 12: w atchdog peripheral identification 7 (wdtperiphid7), offset 0xfdc the wdtperiphidn registers are hard-coded and the fields within the register determine the reset value. w atchdog peripheral identification 7 (wdtperiphid7) base 0x4000.0000 of fset 0xfdc t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid7 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 wdt peripheral id register[31:24] 0x00 ro pid7 7:0 243 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 13: w atchdog peripheral identification 0 (wdtperiphid0), offset 0xfe0 the wdtperiphidn registers are hard-coded and the fields within the register determine the reset value. w atchdog peripheral identification 0 (wdtperiphid0) base 0x4000.0000 of fset 0xfe0 t ype ro, reset 0x0000.0005 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 w atchdog peripheral id register[7:0] 0x05 ro pid0 7:0 june 14, 2007 244 luminary micro confidential-advance product information w atchdog t imer
register 14: w atchdog peripheral identification 1 (wdtperiphid1), offset 0xfe4 the wdtperiphidn registers are hard-coded and the fields within the register determine the reset value. w atchdog peripheral identification 1 (wdtperiphid1) base 0x4000.0000 of fset 0xfe4 t ype ro, reset 0x0000.0018 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 w atchdog peripheral id register[15:8] 0x18 ro pid1 7:0 245 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 15: w atchdog peripheral identification 2 (wdtperiphid2), offset 0xfe8 the wdtperiphidn registers are hard-coded and the fields within the register determine the reset value. w atchdog peripheral identification 2 (wdtperiphid2) base 0x4000.0000 of fset 0xfe8 t ype ro, reset 0x0000.0018 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 w atchdog peripheral id register[23:16] 0x18 ro pid2 7:0 june 14, 2007 246 luminary micro confidential-advance product information w atchdog t imer
register 16: w atchdog peripheral identification 3 (wdtperiphid3), offset 0xfec the wdtperiphidn registers are hard-coded and the fields within the register determine the reset value. w atchdog peripheral identification 3 (wdtperiphid3) base 0x4000.0000 of fset 0xfec t ype ro, reset 0x0000.0001 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 w atchdog peripheral id register[31:24] 0x01 ro pid3 7:0 247 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 17: w atchdog primecell identification 0 (wdtpcellid0), offset 0xff0 the wdtpcellidn registers are hard-coded and the fields within the register determine the reset value. w atchdog primecell identification 0 (wdtpcellid0) base 0x4000.0000 of fset 0xff0 t ype ro, reset 0x0000.000d 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 w atchdog primecell id register[7:0] 0x0d ro cid0 7:0 june 14, 2007 248 luminary micro confidential-advance product information w atchdog t imer
register 18: w atchdog primecell identification 1 (wdtpcellid1), offset 0xff4 the wdtpcellidn registers are hard-coded and the fields within the register determine the reset value. w atchdog primecell identification 1 (wdtpcellid1) base 0x4000.0000 of fset 0xff4 t ype ro, reset 0x0000.00f0 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 w atchdog primecell id register[15:8] 0xf0 ro cid1 7:0 249 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 19: w atchdog primecell identification 2 (wdtpcellid2), offset 0xff8 the wdtpcellidn registers are hard-coded and the fields within the register determine the reset value. w atchdog primecell identification 2 (wdtpcellid2) base 0x4000.0000 of fset 0xff8 t ype ro, reset 0x0000.0005 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 w atchdog primecell id register[23:16] 0x05 ro cid2 7:0 june 14, 2007 250 luminary micro confidential-advance product information w atchdog t imer
register 20: w atchdog primecell identification 3 (wdtpcellid3 ), offset 0xffc the wdtpcellidn registers are hard-coded and the fields within the register determine the reset value. w atchdog primecell identification 3 (wdtpcellid3) base 0x4000.0000 of fset 0xffc t ype ro, reset 0x0000.00b1 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 1 1 0 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 w atchdog primecell id register[31:24] 0xb1 ro cid3 7:0 251 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
12 analog-to-digital converter (adc) adc an analog-to-digital converter (adc) is a peripheral that converts a continuous analog voltage to a discrete digital number . the stellaris ? adc module features 10-bit conversion resolution and supports eight input channels, plus an internal temperature sensor . the adc module contains a programmable sequencer which allows for the sampling of multiple analog input sources without controller intervention. each sample sequence provides flexible programming with fully configurable input source, trigger events, interrupt generation, and sequence priority . the stellaris ? adc provides the following features: eight analog input channels single-ended and dif ferential-input configurations internal temperature sensor sample rate of one million samples/second four programmable sample conversion sequences from one to eight entries long, with corresponding conversion result fifos flexible trigger control C controller (software) C t imers C analog comparators C gpio hardware averaging of up to 64 samples for improved accuracy june 14, 2007 252 luminary micro confidential-advance product information analog-to-digital converter (adc)
12.1 block diagram figure 12-1. adc module block diagram 12.2 functional description the stellaris ? adc collects sample data by using a programmable sequence-based approach instead of the traditional single or double-sampling approach found on many adc modules. each sample sequence is a fully programmed series of consecutive (back-to-back) samples, allowing the adc to collect data from multiple input sources without having to be re-configured or serviced by the controller . the programming of each sample in the sample sequence includes parameters such as the input source and mode (dif ferential versus single-ended input), interrupt generation on sample completion, and the indicator for the last sample in the sequence. 12.2.1 sample sequencers the sampling control and data capture is handled by the sample sequencers. all of the sequencers are identical in implementation except for the number of samples that can be captured and the depth of the fifo. t able 12-1 on page 253 shows the maximum number of samples that each sequencer can capture and its corresponding fifo depth. in this implementation, each fifo entry is a 32-bit word, with the lower 10 bits containing the conversion result. t able 12-1. samples and fifo depth of sequencers depth of fifo number of samples sequencer 1 1 ss3 4 4 ss2 4 4 ss1 8 8 ss0 253 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller analog-to-digital converter adcssfst a t0 adcssctl0 adcssmux0 sample sequencer 0 adcssfst a t1 adcssctl1 adcssmux1 sample sequencer 1 adcssfst a t2 adcssctl2 adcssmux2 sample sequencer 2 adcssfst a t3 adcssctl3 adcssmux3 sample sequencer 3 adcust a t adcost a t adcactss control/status adcsspri adcisc adcris adcim interrupt control analog inputs adcemux adcpssi ss0 interrupt t rigger events ss1 interrupt ss2 interrupt ss3 interrupt ss0 ss1 ss2 ss3 comparator gpio (pb4) t imer pwm comparator gpio (pb4) t imer pwm comparator gpio (pb4) t imer pwm comparator gpio (pb4) t imer pwm adcssfifo0 adcssfifo1 adcssfifo2 adcssfifo3 fifo block hardware a verager adcsac
for a given sample sequence, each sample is defined by two 4-bit nibbles in the adc sample sequence input multiplexer select (adcssmuxn) and adc sample sequence control (adcssctln) registers, where "n" corresponds to the sequence number . the adcssmuxn nibbles select the input pin, while the adcssctln nibbles contain the sample control bits corresponding to parameters such as temperature sensor selection, interrupt enable, end of sequence, and dif ferential input mode. sample sequencers are enabled by setting the respective asenn bit in the adc active sample sequencer (adcactss) register , but can be configured before being enabled. when configuring a sample sequence, multiple uses of the same input pin within the same sequence is allowed. in the adcssctln register , the interrupt enable (ie) bits can be set for any combination of samples, allowing interrupts to be generated after every sample in the sequence if necessary . also, the end bit can be set at any point within a sample sequence. for example, if sequencer 0 is used, the end bit can be set in the nibble associated with the fifth sample, allowing sequencer 0 to complete execution of the sample sequence after the fifth sample. after a sample sequence completes execution, the result data can be retrieved from the adc sample sequence result fifo (adcssfifon) registers. the fifos are simple circular buf fers that read a single address to "pop" result data. for software debug purposes, the positions of the fifo head and tail pointers are visible in the adc sample sequence fifo status (adcssfst a tn) registers along with full and empty status flags. overflow and underflow conditions are monitored using the adcost a t and adcust a t registers. 12.2.2 module control outside of the sample sequencers, the remainder of the control logic is responsible for tasks such as interrupt generation, sequence prioritization, and trigger configuration. most of the adc control logic runs at the adc clock rate of 14-18 mhz. the internal adc divider is configured automatically by hardware when the system xtal is selected. the automatic clock divider configuration targets 16.667 mhz operation for all stellaris ? devices. 12.2.2.1 interrupts the sample sequencers dictate the events that cause interrupts, but they don't have control over whether the interrupt is actually sent to the interrupt controller . the adc module's interrupt signal is controlled by the state of the mask bits in the adc interrupt mask (adcim) register . interrupt status can be viewed at two locations: the adc raw interrupt status (adcris) register , which shows the raw status of a sample sequencer's interrupt signal, and the adc interrupt status and clear (adcisc) register , which shows the logical and of the adcris register s inr bit and the adcim register s mask bits. interrupts are cleared by writing a 1 to the corresponding in bit in adcisc . 12.2.2.2 prioritization when sampling events (triggers) happen concurrently , they are prioritized for processing by the values in the adc sample sequencer priority (adcsspri) register . v alid priority values are in the range of 0-3, with 0 being the highest priority and 3 being the lowest. multiple active sample sequencer units with the same priority do not provide consistent results, so software must ensure that all active sample sequencer units have a unique priority value. 12.2.2.3 sampling events sample triggering for each sample sequencer is defined in the adc event multiplexer select (adcemux) register . the external peripheral triggering sources vary by stellaris ? family member , june 14, 2007 254 luminary micro confidential-advance product information analog-to-digital converter (adc)
but all devices share the "controller" and "always" triggers. software can initiate sampling by setting the ch bits in the adc processor sample sequence initiate (adcpssi) register . when using the "always" trigger , care must be taken. if a sequence's priority is too high, it is possible to starve other lower priority sequences. 12.2.3 hardware sample a veraging circuit higher precision results can be generated using the hardware averaging circuit, however , the improved results are at the cost of throughput. up to 64 samples can be accumulated and averaged to form a single data entry in the sequencer fifo. throughput is decreased proportionally to the number of samples in the averaging calculation. for example, if the averaging circuit is configured to average 16 samples, the throughput is decreased by a factor of 16. by default the averaging circuit is of f and all data from the converter passes through to the sequencer fifo. the averaging hardware is controlled by the adc sample a veraging control (adcsac) register (see page 268 ). there is a single averaging circuit and all input channels receive the same amount of averaging whether they are single-ended or dif ferential. 12.2.4 analog-to-digital converter the converter itself generates a 10-bit output value for selected analog input. special analog pads are used to minimize the distortion on the input. 12.2.5 t est modes there is a user-available test mode that allows for loopback operation within the digital portion of the adc module. this can be useful for debugging software without having to provide actual analog stimulus. this mode is available through the adc t est mode loopback (adctmlb) register (see page 283 ). 12.2.6 internal t emperature sensor the internal temperature sensor provides an analog temperature reading as well as a reference voltage. the voltage at the output terminal senso is given by the following equation: senso = 2.7 - ((t + 55) / 75) this relation is shown in figure 12-2 on page 256 . 255 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
figure 12-2. internal t emperature sensor characteristic 12.3 initialization and configuration in order for the adc module to be used, the pll must be enabled and using a supported crystal frequency (see the rcc register). using unsupported frequencies can cause faulty operation in the adc module. 12.3.1 module initialization initialization of the adc module is a simple process with very few steps. the main steps include enabling the clock to the adc and reconfiguring the sample sequencer priorities (if needed). the initialization sequence for the adc is as follows: 1. enable the adc clock by writing a value of 0x0001.0000 to the rcgc1 register (see page 97 ). 2. if required by the application, reconfigure the sample sequencer priorities in the adcsspri register . the default configuration has sample sequencer 0 with the highest priority , and sample sequencer 3 as the lowest priority . 12.3.2 sample sequencer configuration configuration of the sample sequencers is slightly more complex than the module initialization since each sample sequence is completely programmable. the configuration for each sample sequencer should be as follows: 1. ensure that the sample sequencer is disabled by writing a 0 to the corresponding asen bit in the adcactss register . programming of the sample sequencers is allowed without having them enabled. disabling the sequencer during programming prevents erroneous execution if a trigger event were to occur during the configuration process. 2. configure the trigger event for the sample sequencer in the adcemux register . 3. for each sample in the sample sequence, configure the corresponding input source in the adcssmuxn register . june 14, 2007 256 luminary micro confidential-advance product information analog-to-digital converter (adc)
4. for each sample in the sample sequence, configure the sample control bits in the corresponding nibble in the adcssctln register . when programming the last nibble, ensure that the end bit is set. failure to set the end bit causes unpredictable behavior . 5. if interrupts are to be used, write a 1 to the corresponding mask bit in the adcim register . 6. enable the sample sequencer logic by writing a 1 to the corresponding asen bit in the adcactss register . 12.4 register map t able 12-2 on page 257 lists the adc registers. the of fset listed is a hexadecimal increment to the register s address, relative to the adc base address of 0x4003.8000. t able 12-2. adc register map see page description reset t ype name offset 259 adc active sample sequencer 0x0000.0000 r/w adcactss 0x000 260 adc raw interrupt status 0x0000.0000 ro adcris 0x004 261 adc interrupt mask 0x0000.0000 r/w adcim 0x008 262 adc interrupt status and clear 0x0000.0000 r/w1c adcisc 0x00c 263 adc overflow status 0x0000.0000 r/w1c adcost a t 0x010 264 adc event multiplexer select 0x0000.0000 r/w adcemux 0x014 265 adc underflow status 0x0000.0000 r/w1c adcust a t 0x018 266 adc sample sequencer priority 0x0000.3210 r/w adcsspri 0x020 267 adc processor sample sequence initiate - wo adcpssi 0x028 268 adc sample a veraging control 0x0000.0000 r/w adcsac 0x030 269 adc sample sequence input multiplexer select 0 0x0000.0000 r/w adcssmux0 0x040 271 adc sample sequence control 0 0x0000.0000 r/w adcssctl0 0x044 273 adc sample sequence result fifo 0 0x0000.0000 ro adcssfifo0 0x048 274 adc sample sequence fifo 0 status 0x0000.0100 ro adcssfst a t0 0x04c 275 adc sample sequence input multiplexer select 1 0x0000.0000 r/w adcssmux1 0x060 276 adc sample sequence control 1 0x0000.0000 r/w adcssctl1 0x064 273 adc sample sequence result fifo 1 0x0000.0000 ro adcssfifo1 0x068 274 adc sample sequence fifo 1 status 0x0000.0100 ro adcssfst a t1 0x06c 277 adc sample sequence input multiplexer select 2 0x0000.0000 r/w adcssmux2 0x080 278 adc sample sequence control 2 0x0000.0000 r/w adcssctl2 0x084 273 adc sample sequence result fifo 2 0x0000.0000 ro adcssfifo2 0x088 274 adc sample sequence fifo 2 status 0x0000.0100 ro adcssfst a t2 0x08c 279 adc sample sequence input multiplexer select 3 0x0000.0000 r/w adcssmux3 0x0a0 257 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
see page description reset t ype name offset 280 adc sample sequence control 3 0x0000.0002 r/w adcssctl3 0x0a4 281 adc sample sequence result fifo 3 0x0000.0000 ro adcssfifo3 0x0a8 282 adc sample sequence fifo 3 status 0x0000.0100 ro adcssfst a t3 0x0ac 283 adc t est mode loopback 0x0000.0000 r/w adctmlb 0x100 12.5 register descriptions the remainder of this section lists and describes the adc registers, in numerical order by address of fset. june 14, 2007 258 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 1: adc active sample sequencer (adcactss), offset 0x000 this register controls the activation of the sample sequencers. each sample sequencer can be enabled/disabled independently . adc active sample sequencer (adcactss) base 0x4003.8000 of fset 0x000 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 asen0 asen1 asen2 asen3 reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 specifies whether sample sequencer 3 is enabled. if set, the sample sequence logic for sequencer 3 is active. otherwise, the sequencer is inactive. 0 r/w asen3 3 specifies whether sample sequencer 2 is enabled. if set, the sample sequence logic for sequencer 2 is active. otherwise, the sequencer is inactive. 0 r/w asen2 2 specifies whether sample sequencer 1 is enabled. if set, the sample sequence logic for sequencer 1 is active. otherwise, the sequencer is inactive. 0 r/w asen1 1 specifies whether sample sequencer 0 is enabled. if set, the sample sequence logic for sequencer 0 is active. otherwise, the sequencer is inactive. 0 r/w asen0 0 259 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 2: adc raw interrupt status (adcris), offset 0x004 this register shows the status of the raw interrupt signal of each sample sequencer . these bits may be polled by software to look for interrupt conditions without having to generate controller interrupts. adc raw interrupt status (adcris) base 0x4003.8000 of fset 0x004 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 inr0 inr1 inr2 inr3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 set by hardware when a sample with its respective adcssctl3 ie bit has completed conversion. this bit is cleared by writing a 1 to the adcisc in3 bit. 0 ro inr3 3 set by hardware when a sample with its respective adcssctl2 ie bit has completed conversion. this bit is cleared by writing a 1 to the adcisc in2 bit. 0 ro inr2 2 set by hardware when a sample with its respective adcssctl1 ie bit has completed conversion. this bit is cleared by writing a 1 to the adcisc in1 bit. 0 ro inr1 1 set by hardware when a sample with its respective adcssctl0 ie bit has completed conversion. this bit is cleared by writing a 1 to the adcisc in0 bit. 0 ro inr0 0 june 14, 2007 260 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 3: adc interrupt mask (adcim), offset 0x008 this register controls whether the sample sequencer raw interrupt signals are promoted to controller interrupts. the raw interrupt signal for each sample sequencer can be masked independently . adc interrupt mask (adcim) base 0x4003.8000 of fset 0x008 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mask0 mask1 mask2 mask3 reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 specifies whether the raw interrupt signal from sample sequencer 3 ( adcris register inr3 bit) is promoted to a controller interrupt. if set, the raw interrupt signal is promoted to a controller interrupt. otherwise, it is not. 0 r/w mask3 3 specifies whether the raw interrupt signal from sample sequencer 2 ( adcris register inr2 bit) is promoted to a controller interrupt. if set, the raw interrupt signal is promoted to a controller interrupt. otherwise, it is not. 0 r/w mask2 2 specifies whether the raw interrupt signal from sample sequencer 1 ( adcris register inr1 bit) is promoted to a controller interrupt. if set, the raw interrupt signal is promoted to a controller interrupt. otherwise, it is not. 0 r/w mask1 1 specifies whether the raw interrupt signal from sample sequencer 0 ( adcris register inr0 bit) is promoted to a controller interrupt. if set, the raw interrupt signal is promoted to a controller interrupt. otherwise, it is not. 0 r/w mask0 0 261 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 4: adc interrupt status and clear (adcisc), offset 0x00c this register provides the mechanism for clearing interrupt conditions, and shows the status of controller interrupts generated by the sample sequencers. when read, each bit field is the logical and of the respective inr and mask bits. interrupts are cleared by writing a 1 to the corresponding bit position. if software is polling the adcris instead of generating interrupts, the inr bits are still cleared via the adcisc register , even if the in bit is not set. adc interrupt status and clear (adcisc) base 0x4003.8000 of fset 0x00c t ype r/w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 in0 in1 in2 in3 reserved r/w1c r/w1c r/w1c r/w1c ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 this bit is set by hardware when the mask3 and inr3 bits are both 1, providing a level-based interrupt to the controller . it is cleared by writing a 1, and also clears the inr3 bit. 0 r/w1c in3 3 this bit is set by hardware when the mask2 and inr2 bits are both 1, providing a level based interrupt to the controller . it is cleared by writing a 1, and also clears the inr2 bit. 0 r/w1c in2 2 this bit is set by hardware when the mask1 and inr1 bits are both 1, providing a level based interrupt to the controller . it is cleared by writing a 1, and also clears the inr1 bit. 0 r/w1c in1 1 this bit is set by hardware when the mask0 and inr0 bits are both 1, providing a level based interrupt to the controller . it is cleared by writing a 1, and also clears the inr0 bit. 0 r/w1c in0 0 june 14, 2007 262 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 5: adc overflow status (adcost a t), offset 0x010 this register indicates overflow conditions in the sample sequencer fifos. once the overflow condition has been handled by software, the condition can be cleared by writing a 1 to the corresponding bit position. adc overflow status (adcost a t) base 0x4003.8000 of fset 0x010 t ype r/w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ov0 ov1 ov2 ov3 reserved r/w1c r/w1c r/w1c r/w1c ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 this bit specifies that the fifo for sample sequencer 3 has hit an overflow condition where the fifo is full and a write was requested. when an overflow is detected, the most recent write is dropped and this bit is set by hardware to indicate the occurrence of dropped data. this bit is cleared by writing a 1. 0 r/w1c ov3 3 this bit specifies that the fifo for sample sequencer 2 has hit an overflow condition where the fifo is full and a write was requested. when an overflow is detected, the most recent write is dropped and this bit is set by hardware to indicate the occurrence of dropped data. this bit is cleared by writing a 1. 0 r/w1c ov2 2 this bit specifies that the fifo for sample sequencer 1 has hit an overflow condition where the fifo is full and a write was requested. when an overflow is detected, the most recent write is dropped and this bit is set by hardware to indicate the occurrence of dropped data. this bit is cleared by writing a 1. 0 r/w1c ov1 1 this bit specifies that the fifo for sample sequencer 0 has hit an overflow condition where the fifo is full and a write was requested. when an overflow is detected, the most recent write is dropped and this bit is set by hardware to indicate the occurrence of dropped data. this bit is cleared by writing a 1. 0 r/w1c ov0 0 263 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 6: adc event multiplexer select (adcemux), offset 0x014 the adcemux selects the event (trigger) that initiates sampling for each sample sequencer . each sample sequencer can be configured with a unique trigger source. adc event multiplexer select (adcemux) base 0x4003.8000 of fset 0x014 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 em0 em1 em2 em3 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 this field selects the trigger source for sample sequencer 3. the valid configurations for this field are: event em binary v alue controller (default) 0000 analog comparator 0 0001 analog comparator 1 0010 analog comparator 2 001 1 external (gpio pb4) 0100 t imer 0101 reserved 01 10 reserved 01 1 1 reserved 1000 reserved 1001-1 1 10 always (continuously sample) 1 1 1 1 0 r/w em3 15:12 this field selects the trigger source for sample sequencer 2. the encodings are the same as those for em3. 0 r/w em2 1 1:8 this field selects the trigger source for sample sequencer 1. the encodings are the same as those for em3. 0 r/w em1 7:4 this field selects the trigger source for sample sequencer 0. the encodings are the same as those for em3. 0 r/w em0 3:0 june 14, 2007 264 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 7: adc underflow status (adcust a t), offset 0x018 this register indicates underflow conditions in the sample sequencer fifos. the corresponding underflow condition can be cleared by writing a 1 to the relevant bit position. adc underflow status (adcust a t) base 0x4003.8000 of fset 0x018 t ype r/w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 uv0 uv1 uv2 uv3 reserved r/w1c r/w1c r/w1c r/w1c ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 this bit specifies that the fifo for sample sequencer 3 has hit an underflow condition where the fifo is empty and a read was requested. the problematic read does not move the fifo pointers, and 0s are returned. this bit is cleared by writing a 1. 0 r/w1c uv3 3 this bit specifies that the fifo for sample sequencer 2 has hit an underflow condition where the fifo is empty and a read was requested. the problematic read does not move the fifo pointers, and 0s are returned. this bit is cleared by writing a 1. 0 r/w1c uv2 2 this bit specifies that the fifo for sample sequencer 1 has hit an underflow condition where the fifo is empty and a read was requested. the problematic read does not move the fifo pointers, and 0s are returned. this bit is cleared by writing a 1. 0 r/w1c uv1 1 this bit specifies that the fifo for sample sequencer 0 has hit an underflow condition where the fifo is empty and a read was requested. the problematic read does not move the fifo pointers, and 0s are returned. this bit is cleared by writing a 1. 0 r/w1c uv0 0 265 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 8: adc sample sequencer priority (adcsspri), offset 0x020 this register sets the priority for each of the sample sequencers. out of reset, sequencer 0 has the highest priority , and sample sequence 3 has the lowest priority . when reconfiguring sequence priorities, each sequence must have a unique priority or the adc behavior is inconsistent. adc sample sequencer priority (adcsspri) base 0x4003.8000 of fset 0x020 t ype r/w , reset 0x0000.3210 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ss0 reserved ss1 reserved ss2 reserved ss3 reserved r/w r/w ro ro r/w r/w ro ro r/w r/w ro ro r/w r/w ro ro t ype 0 0 0 0 1 0 0 0 0 1 0 0 1 1 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:14 the ss3 field contains a binary-encoded value that specifies the priority encoding of sample sequencer 3. a priority encoding of 0 is highest and 3 is lowest. the priorities assigned to the sequencers must be uniquely mapped. adc behavior is not consistent if two or more fields are equal. 0x3 r/w ss3 13:12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1:10 the ss2 field contains a binary-encoded value that specifies the priority encoding of sample sequencer 2. 0x2 r/w ss2 9:8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7:6 the ss1 field contains a binary-encoded value that specifies the priority encoding of sample sequencer 1. 0x1 r/w ss1 5:4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3:2 the ss0 field contains a binary-encoded value that specifies the priority encoding of sample sequencer 0. 0x0 r/w ss0 1:0 june 14, 2007 266 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 9: adc processor sample sequence initiate (adcpssi), offset 0x028 this register provides a mechanism for application software to initiate sampling in the sample sequencers. sample sequences can be initiated individually or in any combination. when multiple sequences are triggered simultaneously , the priority encodings in adcsspri dictate execution order . adc processor sample sequence initiate (adcpssi) base 0x4003.8000 of fset 0x028 t ype wo, reset - 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo t ype - - - - - - - - - - - - - - - - reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ss0 ss1 ss2 ss3 reserved wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo t ype - - - - - - - - - - - - - - - - reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. - wo reserved 31:4 only a write by software is valid; a read of the register returns no meaningful data. when set by software, sampling is triggered on sample sequencer 3, assuming the sequencer is enabled in the adcactss register . - wo ss3 3 only a write by software is valid; a read of the register returns no meaningful data. when set by software, sampling is triggered on sample sequencer 2, assuming the sequencer is enabled in the adcactss register . - wo ss2 2 only a write by software is valid; a read of the register returns no meaningful data. when set by software, sampling is triggered on sample sequencer 1, assuming the sequencer is enabled in the adcactss register . - wo ss1 1 only a write by software is valid; a read of the register returns no meaningful data. when set by software, sampling is triggered on sample sequencer 0, assuming the sequencer is enabled in the adcactss register . - wo ss0 0 267 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 10: adc sample a veraging control (adcsac), offset 0x030 this register controls the amount of hardware averaging applied to conversion results. the final conversion result stored in the fifo is averaged from 2 a vg consecutive adc samples at the specified adc speed. if a vg is 0, the sample is passed directly through without any averaging. if a vg=6, then 64 consecutive adc samples are averaged to generate one result in the sequencer fifo. an a vg = 7 provides unpredictable results. adc sample a veraging control (adcsac) base 0x4003.8000 of fset 0x030 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 a vg reserved r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:3 specifies the amount of hardware averaging that will be applied to adc samples. the avg field can be any value between 0 and 6. entering a value of 7 creates unpredictable results. 0 r/w a vg 2:0 june 14, 2007 268 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 1 1: adc sample sequence input multiplexer select 0 (adcssmux0), offset 0x040 this register defines the analog input configuration for each sample in a sequence executed with sample sequencer 0. this register is 32-bits wide and contains information for eight possible samples. adc sample sequence input multiplexer select 0 (adcssmux0) base 0x4003.8000 of fset 0x040 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 mux4 reserved mux5 reserved mux6 reserved mux7 reserved r/w r/w r/w ro r/w r/w r/w ro r/w r/w r/w ro r/w r/w r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mux0 reserved mux1 reserved mux2 reserved mux3 reserved r/w r/w r/w ro r/w r/w r/w ro r/w r/w r/w ro r/w r/w r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31 the mux7 field is used during the eighth sample of a sequence executed with the sample sequencer . it specifies which of the analog inputs is sampled for the analog-to-digital conversion. the value set here indicates the corresponding pin, for example, a value of 1 indicates the input is adc1 . 0 r/w mux7 30:28 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 27 the mux6 field is used during the seventh sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux6 26:24 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 23 the mux5 field is used during the sixth sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux5 22:20 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 19 the mux4 field is used during the fifth sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux4 18:16 269 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 15 the mux3 field is used during the fourth sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux3 14:12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1 the mux2 field is used during the third sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux2 10:8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7 the mux1 field is used during the second sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux1 6:4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3 the mux0 field is used during the first sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux0 2:0 june 14, 2007 270 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 12: adc sample sequence control 0 (adcssctl0), offset 0x044 this register contains the configuration information for each sample for a sequence executed with sample sequencer 0. when configuring a sample sequence, the end bit must be set at some point, whether it be after the first sample, last sample, or any sample in between. this register is 32-bits wide and contains information for eight possible samples. adc sample sequence control 0 (adcssctl0) base 0x4003.8000 of fset 0x044 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 d4 end4 ie4 ts4 d5 end5 ie5 ts5 d6 end6 ie6 ts6 d7 end7 ie7 ts7 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 d0 end0 ie0 ts0 d1 end1 ie1 ts1 d2 end2 ie2 ts2 d3 end3 ie3 ts3 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field the ts7 bit is used during the eighth sample of the sample sequence and specifies the input source of the sample. if set, the temperature sensor is read. otherwise, the input pin specified by the adcssmux register is read. 0 r/w ts7 31 the ie7 bit is used during the eighth sample of the sample sequence and specifies whether the raw interrupt signal ( inr0 bit) is asserted at the end of the sample's conversion. if the mask0 bit in the adcim register is set, the interrupt is promoted to a controller-level interrupt. when this bit is set, the raw interrupt is asserted, otherwise it is not. it is legal to have multiple samples within a sequence generate interrupts. 0 r/w ie7 30 the end7 bit indicates that this is the last sample of the sequence. it is possible to end the sequence on any sample position. samples defined after the sample containing a set end are not requested for conversion even though the fields may be non-zero. it is required that software write the end bit somewhere within the sequence. (sample sequencer 3, which only has a single sample in the sequence, is hardwired to have the end0 bit set.) setting this bit indicates that this sample is the last in the sequence. 0 r/w end7 29 the d7 bit indicates that the analog input is to be dif ferentially sampled. the corresponding adcssmuxx nibble must be set to the pair number "i", where the paired inputs are "2i and 2i+1". the temperature sensor does not have a dif ferential option. when set, the analog inputs are dif ferentially sampled. 0 r/w d7 28 same definition as ts7 but used during the seventh sample. 0 r/w ts6 27 same definition as ie7 but used during the seventh sample. 0 r/w ie6 26 same definition as end7 but used during the seventh sample. 0 r/w end6 25 same definition as d7 but used during the seventh sample. 0 r/w d6 24 same definition as ts7 but used during the sixth sample. 0 r/w ts5 23 271 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field same definition as ie7 but used during the sixth sample. 0 r/w ie5 22 same definition as end7 but used during the sixth sample. 0 r/w end5 21 same definition as d7 but used during the sixth sample. 0 r/w d5 20 same definition as ts7 but used during the fifth sample. 0 r/w ts4 19 same definition as ie7 but used during the fifth sample. 0 r/w ie4 18 same definition as end7 but used during the fifth sample. 0 r/w end4 17 same definition as d7 but used during the fifth sample. 0 r/w d4 16 same definition as ts7 but used during the fourth sample. 0 r/w ts3 15 same definition as ie7 but used during the fourth sample. 0 r/w ie3 14 same definition as end7 but used during the fourth sample. 0 r/w end3 13 same definition as d7 but used during the fourth sample. 0 r/w d3 12 same definition as ts7 but used during the third sample. 0 r/w ts2 1 1 same definition as ie7 but used during the third sample. 0 r/w ie2 10 same definition as end7 but used during the third sample. 0 r/w end2 9 same definition as d7 but used during the third sample. 0 r/w d2 8 same definition as ts7 but used during the second sample. 0 r/w ts1 7 same definition as ie7 but used during the second sample. 0 r/w ie1 6 same definition as end7 but used during the second sample. 0 r/w end1 5 same definition as d7 but used during the second sample. 0 r/w d1 4 same definition as ts7 but used during the first sample. 0 r/w ts0 3 same definition as ie7 but used during the first sample. 0 r/w ie0 2 same definition as end7 but used during the first sample. since this sequencer has only one entry , this bit must be set. 0 r/w end0 1 same definition as d7 but used during the first sample. 0 r/w d0 0 june 14, 2007 272 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 13: adc sample sequence result fifo 0 (adcssfifo0), offset 0x048 register 14: adc sample sequence result fifo 1 (adcssfifo1), offset 0x068 register 15: adc sample sequence result fifo 2 (adcssfifo2), offset 0x088 this register contains the conversion results for samples collected with the sample sequencer (the adcssfif0 register is used for sample sequencer 0, adcssfifo1 for sequencer 1, and adcssfifo2 for sequencer 2). reads of this register return conversion result data in the order sample 0, sample 1, and so on, until the fifo is empty . if the fifo is not properly handled by software, overflow and underflow conditions are registered in the adcost a t and adcust a t registers. adc sample sequence result fifo 0 (adcssfifo0) base 0x4003.8000 of fset 0x048 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:10 conversion result data. 0 ro da t a 9:0 273 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 16: adc sample sequence fifo 0 status (adcssfst a t0), offset 0x04c register 17: adc sample sequence fifo 1 status (adcssfst a t1), offset 0x06c register 18: adc sample sequence fifo 2 status (adcssfst a t2), offset 0x08c this register provides a window into the sample sequencer , providing full/empty status information as well as the positions of the head and tail pointers. the reset value of 0x100 indicates an empty fifo. the adcssfst a t0 register provides status on fif0, adcssfst a t1 on fifo1, and adcssfst a t2 on fifo2. adc sample sequence fifo 0 status (adcssfst a t0) base 0x4003.8000 of fset 0x04c t ype ro, reset 0x0000.0100 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tptr hptr empty reserved full reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:13 when set, indicates that the fifo is currently full. 0 ro full 12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1:9 when set, indicates that the fifo is currently empty . 1 ro empty 8 this field contains the current "head" pointer index for the fifo, that is, the next entry to be written. 0 ro hptr 7:4 this field contains the current "tail" pointer index for the fifo, that is, the next entry to be read. 0 ro tptr 3:0 june 14, 2007 274 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 19: adc sample sequence input multiplexer select 1 (adcssmux1), offset 0x060 this register defines the analog input configuration for each sample in a sequence executed with sample sequencer 1. this register is 16-bits wide and contains information for four possible samples. adc sample sequence input multiplexer select 1 (adcssmux1) base 0x4003.8000 of fset 0x060 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mux0 reserved mux1 reserved mux2 reserved mux3 reserved r/w r/w r/w ro r/w r/w r/w ro r/w r/w r/w ro r/w r/w r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:15 the mux3 field is used during the fourth sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux3 14:12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1 the mux2 field is used during the third sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux2 10:8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7 the mux1 field is used during the second sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux1 6:4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3 the mux0 field is used during the first sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux0 2:0 275 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 20: adc sample sequence control 1 (adcssctl1), offset 0x064 this register contains the configuration information for each sample for a sequence executed with sample sequencer 1. when configuring a sample sequence, the end bit must be set at some point, whether it be after the first sample, last sample, or any sample in between. this register is 16-bits wide and contains information for four possible samples. adc sample sequence control 1 (adcssctl1) base 0x4003.8000 of fset 0x064 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 d0 end0 ie0 ts0 d1 end1 ie1 ts1 d2 end2 ie2 ts2 d3 end3 ie3 ts3 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 same definition as ts7 but used during the fourth sample. 0 r/w ts3 15 same definition as ie7 but used during the fourth sample. 0 r/w ie3 14 same definition as end7 but used during the fourth sample. 0 r/w end3 13 same definition as d7 but used during the fourth sample. 0 r/w d3 12 same definition as ts7 but used during the third sample. 0 r/w ts2 1 1 same definition as ie7 but used during the third sample. 0 r/w ie2 10 same definition as end7 but used during the third sample. 0 r/w end2 9 same definition as d7 but used during the third sample. 0 r/w d2 8 same definition as ts7 but used during the second sample. 0 r/w ts1 7 same definition as ie7 but used during the second sample. 0 r/w ie1 6 same definition as end7 but used during the second sample. 0 r/w end1 5 same definition as d7 but used during the second sample. 0 r/w d1 4 same definition as ts7 but used during the first sample. 0 r/w ts0 3 same definition as ie7 but used during the first sample. 0 r/w ie0 2 same definition as end7 but used during the first sample. since this sequencer has only one entry , this bit must be set. 0 r/w end0 1 same definition as d7 but used during the first sample. 0 r/w d0 0 june 14, 2007 276 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 21: adc sample sequence input multiplexer select 2 (adcssmux2), offset 0x080 this register defines the analog input configuration for each sample in a sequence executed with sample sequencer 2. this register is 16-bits wide and contains information for four possible samples. adc sample sequence input multiplexer select 2 (adcssmux2) base 0x4003.8000 of fset 0x080 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mux0 reserved mux1 reserved mux2 reserved mux3 reserved r/w r/w r/w ro r/w r/w r/w ro r/w r/w r/w ro r/w r/w r/w ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:15 the mux3 field is used during the fourth sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux3 14:12 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 1 1 the mux2 field is used during the third sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux2 10:8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7 the mux1 field is used during the second sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux1 6:4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3 the mux0 field is used during the first sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux0 2:0 277 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 22: adc sample sequence control 2 (adcssctl2), offset 0x084 this register contains the configuration information for each sample for a sequence executed with sample sequencer 2. when configuring a sample sequence, the end bit must be set at some point, whether it be after the first sample, last sample, or any sample in between. this register is 16-bits wide and contains information for four possible samples. adc sample sequence control 2 (adcssctl2) base 0x4003.8000 of fset 0x084 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 d0 end0 ie0 ts0 d1 end1 ie1 ts1 d2 end2 ie2 ts2 d3 end3 ie3 ts3 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 same definition as ts7 but used during the fourth sample. 0 r/w ts3 15 same definition as ie7 but used during the fourth sample. 0 r/w ie3 14 same definition as end7 but used during the fourth sample. 0 r/w end3 13 same definition as d7 but used during the fourth sample. 0 r/w d3 12 same definition as ts7 but used during the third sample. 0 r/w ts2 1 1 same definition as ie7 but used during the third sample. 0 r/w ie2 10 same definition as end7 but used during the third sample. 0 r/w end2 9 same definition as d7 but used during the third sample. 0 r/w d2 8 same definition as ts7 but used during the second sample. 0 r/w ts1 7 same definition as ie7 but used during the second sample. 0 r/w ie1 6 same definition as end7 but used during the second sample. 0 r/w end1 5 same definition as d7 but used during the second sample. 0 r/w d1 4 same definition as ts7 but used during the first sample. 0 r/w ts0 3 same definition as ie7 but used during the first sample. 0 r/w ie0 2 same definition as end7 but used during the first sample. since this sequencer has only one entry , this bit must be set. 0 r/w end0 1 same definition as d7 but used during the first sample. 0 r/w d0 0 june 14, 2007 278 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 23: adc sample sequence input multiplexer select 3 (adcssmux3), offset 0x0a0 this register defines the analog input configuration for each sample in a sequence executed with sample sequencer 3. this register is 4-bits wide and contains information for one possible sample. adc sample sequence input multiplexer select 3 (adcssmux3) base 0x4003.8000 of fset 0x0a0 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mux0 reserved r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:3 the mux0 field is used during the first sample of a sequence executed with the sample sequencer and specifies which of the analog inputs is sampled for the analog-to-digital conversion. 0 r/w mux0 2:0 279 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 24: adc sample sequence control 3 (adcssctl3), offset 0x0a4 this register contains the configuration information for each sample for a sequence executed with sample sequencer 3. the end bit is always set since there is only one sample in this sequencer . this register is 4-bits wide and contains information for one possible sample. adc sample sequence control 3 (adcssctl3) base 0x4003.8000 of fset 0x0a4 t ype r/w , reset 0x0000.0002 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 d0 end0 ie0 ts0 reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 same definition as ts7 but used during the first sample. 0 r/w ts0 3 same definition as ie7 but used during the first sample. 0 r/w ie0 2 same definition as end7 but used during the first sample. since this sequencer has only one entry , this bit must be set. 0 r/w end0 1 same definition as d7 but used during the first sample. 0 r/w d0 0 june 14, 2007 280 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 25: adc sample sequence result fifo 3 (adcssfifo3), offset 0x0a8 this register contains the conversion results for samples collected with sample sequencer 3. reads of this register return the conversion result data. if the fifo is not properly handled by software, overflow and underflow conditions are registered in the adcost a t and adcust a t registers. bit fields and definitions are the same as adcssfifo0 (see page 273 ) but are for fifo 3. 281 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 26: adc sample sequence fifo 3 status (adcssfst a t3), offset 0x0ac this register provides a window into the sample sequencer fifo 3, providing full/empty status information as well as the positions of the head and tail pointers. the reset value of 0x100 indicates an empty fifo. this register has the same bit fields and definitions as adcssfst a t0 (see page 274 ) but is for fifo 3. june 14, 2007 282 luminary micro confidential-advance product information analog-to-digital converter (adc)
register 27: adc t est mode loopback (adctmlb), offset 0x100 this register provides loopback operation within the digital logic of the adc, which can be useful in debugging software without having to provide actual analog stimulus. this test mode is entered by writing a value of 0x0000.0001 to this register . when data is read from the fifo in loopback mode, the read-only portion of this register is returned. read-only register adc t est mode loopback (adctmlb) base 0x4003.8000 of fset 0x100 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mux ts diff cont cnt reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:10 continuous sample counter that is initialized to 0 and counts each sample as it processed. this helps provide a unique value for the data received. 0 ro cnt 9:6 when set, indicates that this is a continuation sample. for example if two sequencers were to run back-to-back, this indicates that the controller kept continuously sampling at full rate. 0 ro cont 5 when set, indicates that this is a dif ferential sample. 0 ro diff 4 when set, indicates that this is a temperature sensor sample. 0 ro ts 3 indicates which analog input is to be sampled. 0 ro mux 2:0 w rite-only register adc t est mode loopback (adctmlb) base 0x4003.8000 of fset 0x100 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 lb reserved wo ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 283 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 when set, forces a loopback within the digital block to provide information on input and unique numbering. the 10-bit loopback data is defined as shown in the read for bits 9:0 below . 0 wo lb 0 june 14, 2007 284 luminary micro confidential-advance product information analog-to-digital converter (adc)
13 universal asynchronous receivers/t ransmitters (uart s) uar t the stellaris ? universal asynchronous receiver/t ransmitter (uar t) provides fully programmable, 16c550-type serial interface characteristics. the lm3s8938 controller is equipped with three uar t modules. each uar t has the following features: separate transmit and receive fifos programmable fifo length, including 1-byte deep operation providing conventional double-buf fered interface fifo trigger levels of 1/8, 1/4, 1/2, 3/4, and 7/8 programmable baud-rate generator allowing rates up to 460.8 kbps standard asynchronous communication bits for start, stop and parity false start bit detection line-break generation and detection fully programmable serial interface characteristics: C 5, 6, 7, or 8 data bits C even, odd, stick, or no-parity bit generation/detection C 1 or 2 stop bit generation irda serial-ir (sir) encoder/decoder providing: C programmable use of irda serial infrared (sir) or uar t input/output C support of irda sir encoder/decoder functions for data rates up to 1 15.2 kbps half-duplex C support of normal 3/16 and low-power (1.41-2.23 s) bit durations C programmable internal clock generator enabling division of reference clock by 1 to 256 for low-power mode bit duration 285 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
13.1 block diagram figure 13-1. uart module block diagram 13.2 functional description each stellaris ? uar t performs the functions of parallel-to-serial and serial-to-parallel conversions. it is similar in functionality to a 16c550 uar t , but is not register compatible. the uar t is configured for transmit and/or receive via the txe and rxe bits of the uart control (uartctl) register (see page 304 ). t ransmit and receive are both enabled out of reset. before any control registers are programmed, the uar t must be disabled by clearing the uarten bit in uartctl . if the uar t is disabled during a tx or rx operation, the current transaction is completed prior to the uar t stopping. the uar t peripheral also includes a serial ir (sir) encoder/decoder block that can be connected to an infrared transceiver to implement an irda sir physical layer . the sir function is programmed using the uar tctl register . 13.2.1 t ransmit/receive logic the transmit logic performs parallel-to-serial conversion on the data read from the transmit fifo. the control logic outputs the serial bit stream beginning with a start bit, and followed by the data june 14, 2007 286 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s) receiver t ransmitter system clock control / status uar trsr / ecr uar tfr uar tlcrh uar tctl uar tilpr interrupt control uar tifls uar tim uar tmis uar tris uar ticr baud rate generator uar tibrd uar tfbrd identification registers uar tpcellid 0 uar tpcellid 1 uar tpcellid 2 uar tpcellid 3 uar tperiphid 0 uar tperiphid 1 uar tperiphid 2 uar tperiphid 3 uar t periphid 4 uar tperiphid 5 uar tperiphid 6 uar tperiphid 7 uar tdr txfifo 16 x 8 . . . rxfifo 16 x 8 . . . interrupt untx unrx
bits (lsb first), parity bit, and the stop bits according to the programmed configuration in the control registers. see figure 13-2 on page 287 for details. the receive logic performs serial-to-parallel conversion on the received bit stream after a valid start pulse has been detected. overrun, parity , frame error checking, and line-break detection are also performed, and their status accompanies the data that is written to the receive fifo. figure 13-2. uart character frame 13.2.2 baud-rate generation the baud-rate divisor is a 22-bit number consisting of a 16-bit integer and a 6-bit fractional part. the number formed by these two values is used by the baud-rate generator to determine the bit period. having a fractional baud-rate divider allows the uar t to generate all the standard baud rates. the 16-bit integer is loaded through the uart integer baud-rate divisor (uartibrd) register (see page 300 ) and the 6-bit fractional part is loaded with the uart fractional baud-rate divisor (uartfbrd) register (see page 301 ). the baud-rate divisor (brd) has the following relationship to the system clock (where brdi is the integer part of the brd and brdf is the fractional part, separated by a decimal place.): brd = brdi + brdf = sysclk / (16 * baud rate) the 6-bit fractional number (that is to be loaded into the divfrac bit field in the uartfbrd register) can be calculated by taking the fractional part of the baud-rate divisor , multiplying it by 64, and adding 0.5 to account for rounding errors: uartfbrd[divfrac] = integer(brdf * 64 + 0.5) the uar t generates an internal baud-rate reference clock at 16x the baud-rate (referred to as baud16 ). this reference clock is divided by 16 to generate the transmit clock, and is used for error detection during receive operations. along with the uart line control, high byte (uartlcrh) register (see page 302 ), the uartibrd and uartfbrd registers form an internal 30-bit register . this internal register is only updated when a write operation to uartlcrh is performed, so any changes to the baud-rate divisor must be followed by a write to the uartlcrh register for the changes to take ef fect. t o update the baud-rate registers, there are four possible sequences: uartibrd write, uartfbrd write, and uartlcrh write uartfbrd write, uartibrd write, and uartlcrh write uartibrd write and uartlcrh write uartfbrd write and uartlcrh write 287 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller 1 0 5 - 8 d a t a b i t s l s b m s b p a r i t y b i t i f e n a b l e d 1 - 2 s t o p b i t s u n t x n s t a r t
13.2.3 data t ransmission data received or transmitted is stored in two 16-byte fifos, though the receive fifo has an extra four bits per character for status information. for transmission, data is written into the transmit fifo. if the uar t is enabled, it causes a data frame to start transmitting with the parameters indicated in the uartlcrh register . data continues to be transmitted until there is no data left in the transmit fifo. the busy bit in the uart flag (uartfr) register (see page 297 ) is asserted as soon as data is written to the transmit fifo (that is, if the fifo is non-empty) and remains asserted while data is being transmitted. the busy bit is negated only when the transmit fifo is empty , and the last character has been transmitted from the shift register , including the stop bits. the uar t can indicate that it is busy even though the uar t may no longer be enabled. when the receiver is idle (the unrx is continuously 1) and the data input goes low (a start bit has been received), the receive counter begins running and data is sampled on the eighth cycle of baud16 (described in t ransmit/receive logic on page 286 ). the start bit is valid if unrx is still low on the eighth cycle of baud16 , otherwise a false start bit is detected and it is ignored. start bit errors can be viewed in the uart receive status (uartrsr) register (see page 295 ). if the start bit was valid, successive data bits are sampled on every 16th cycle of baud16 (that is, one bit period later) according to the programmed length of the data characters. the parity bit is then checked if parity mode was enabled. data length and parity are defined in the uartlcrh register . lastly , a valid stop bit is confirmed if unrx is high, otherwise a framing error has occurred. when a full word is received, the data is stored in the receive fifo, with any error bits associated with that word. 13.2.4 serial ir (sir) the uar t peripheral includes an irda serial-ir (sir) encoder/decoder block. the irda sir block provides functionality that converts between an asynchronous uar t data stream, and half-duplex serial sir interface. no analog processing is performed on-chip. the role of the sir block is to provide a digital encoded output, and decoded input to the uar t . the uar t signal pins can be connected to an infrared transceiver to implement an irda sir physical layer link. the sir block has two modes of operation: in normal irda mode, a zero logic level is transmitted as high pulse of 3/16th duration of the selected baud rate bit period on the output pin, while logic one levels are transmitted as a static low signal. these levels control the driver of an infrared transmitter , sending a pulse of light for each zero. on the reception side, the incoming light pulses energize the photo transistor base of the receiver , pulling its output low . this drives the uar t input pin low . in low-power irda mode, the width of the transmitted infrared pulse is set to three times the period of the internally generated irlpbaud16 signal (1.63 s, assuming a nominal 1.8432 mhz frequency) by changing the appropriate bit in the uartcr register . figure 13-3 on page 289 shows the uar t transmit and receive signals, with and without irda modulation. june 14, 2007 288 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
figure 13-3. irda data modulation in both normal and low-power irda modes: during transmission, the uar t data bit is used as the base for encoding during reception, the decoded bits are transferred to the uar t receive logic the irda sir physical layer specifies a half-duplex communication link, with a minimum 10 ms delay between transmission and reception. this delay must be generated by software because it is not automatically supported by the uar t . the delay is required because the infrared receiver electronics might become biased, or even saturated from the optical power coupled from the adjacent transmitter led. this delay is known as latency , or receiver setup time. 13.2.5 fifo operation the uar t has two 16-entry fifos; one for transmit and one for receive. both fifos are accessed via the uart data (uartdr) register (see page 293 ). read operations of the uartdr register return a 12-bit value consisting of 8 data bits and 4 error flags while write operations place 8-bit data in the transmit fifo. out of reset, both fifos are disabled and act as 1-byte-deep holding registers. the fifos are enabled by setting the fen bit in uartlcrh ( page 302 ). fifo status can be monitored via the uart flag (uartfr) register (see page 297 ) and the uart receive status (uartrsr) register . hardware monitors empty , full and overrun conditions. the uartfr register contains empty and full flags ( txfe , txff , rxfe and rxff bits) and the uartrsr register shows overrun status via the oe bit. the trigger points at which the fifos generate interrupts is controlled via the uart interrupt fifo level select (uartifls) register (see page 306 ). both fifos can be individually configured to trigger interrupts at dif ferent levels. a vailable configurations include 1/8, ?, ?, ?, and 7/8. for example, if the ? option is selected for the receive fifo, the uar t generates a receive interrupt after 4 data bytes are received. out of reset, both fifos are configured to trigger an interrupt at the ? mark. 13.2.6 interrupts the uar t can generate interrupts when the following conditions are observed: overrun error break error 289 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller 1 0 1 0 0 0 1 1 0 1 d a t a b i t s 1 0 1 0 0 0 1 1 0 1 d a t a b i t s s t a r t b i t s t a r t s t o p b i t p e r i o d b i t p e r i o d 3 1 6 u n t x u n t x w i t h i r d a u n r x w i t h i r d a unrx s t o p b i t
parity error framing error receive t imeout t ransmit (when condition defined in the txiflsel bit in the uartifls register is met) receive (when condition defined in the rxiflsel bit in the uartifls register is met) all of the interrupt events are ored together before being sent to the interrupt controller , so the uar t can only generate a single interrupt request to the controller at any given time. software can service multiple interrupt events in a single interrupt service routine by reading the uart masked interrupt status (uartmis) register (see page 310 ). the interrupt events that can trigger a controller-level interrupt are defined in the uart interrupt mask (uartim ) register (see page 307 ) by setting the corresponding im bit to 1. if interrupts are not used, the raw interrupt status is always visible via the uart raw interrupt status (uartris) register (see page 309 ). interrupts are always cleared (for both the uartmis and uartris registers) by setting the corresponding bit in the uart interrupt clear (uarticr) register (see page 311 ). 13.2.7 loopback operation the uar t can be placed into an internal loopback mode for diagnostic or debug work. this is accomplished by setting the lbe bit in the uartctl register (see page 304 ). in loopback mode, data transmitted on untx is received on the unrx input. 13.2.8 irda sir block the irda sir block contains an irda serial ir (sir) protocol encoder/decoder . when enabled, the sir block uses the untx and unrx pins for the sir protocol, which should be connected to an ir transceiver . the sir block can receive and transmit, but it is only half-duplex so it cannot do both at the same time. t ransmission must be stopped before data can be received. the irda sir physcial layer specifies a minimum 10-ms delay between transmission and reception. 13.3 initialization and configuration t o use the uar t s, the peripheral clock must be enabled by setting the uart0 , uart1 , or uart2 bits in the rcgc1 register . this section discusses the steps that are required for using a uar t module. for this example, the system clock is assumed to be 20 mhz and the desired uar t configuration is: 1 15200 baud rate data length of 8 bits one stop bit no parity fifos disabled june 14, 2007 290 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
no interrupts the first thing to consider when programming the uar t is the baud-rate divisor (brd), since the uartibrd and uartfbrd registers must be written before the uartlcrh register . using the equation described in baud-rate generation on page 287 , the brd can be calculated: brd = 20,000,000 / (16 * 115,200) = 10.8507 which means that the divint field of the uartibrd register (see page 300 ) should be set to 10. the value to be loaded into the uartfbrd register (see page 301 ) is calculated by the equation: uartfbrd[divfrac] = integer(0.8507 * 64 + 0.5) = 54 with the brd values in hand, the uar t configuration is written to the module in the following order: 1. disable the uar t by clearing the uarten bit in the uartctl register . 2. w rite the integer portion of the brd to the uartibrd register . 3. w rite the fractional portion of the brd to the uartfbrd register . 4. w rite the desired serial parameters to the uartlcrh register (in this case, a value of 0x0000.0060). 5. enable the uar t by setting the uarten bit in the uartctl register . 13.4 register map t able 13-1 on page 291 lists the uar t registers. the of fset listed is a hexadecimal increment to the register s address, relative to that uar t s base address: uar t0: 0x4000.c000 uar t1: 0x4000.d000 uar t2: 0x4000.e000 note: the uar t must be disabled (see the uarten bit in the uartctl register on page 304 ) before any of the control registers are reprogrammed. when the uar t is disabled during a tx or rx operation, the current transaction is completed prior to the uar t stopping. t able 13-1. uart register map see page description reset t ype name offset 293 uar t data 0x0000.0000 ro uar tdr 0x000 295 uar t receive status/error clear 0x0000.0000 r/w uar trsr/uar tecr 0x004 297 uar t flag 0x0000.0090 ro uar tfr 0x018 299 uar t irda low-power register 0x0000.0000 r/w uar tilpr 0x020 300 uar t integer baud-rate divisor 0x0000.0000 r/w uar tibrd 0x024 301 uar t fractional baud-rate divisor 0x0000.0000 r/w uar tfbrd 0x028 291 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
see page description reset t ype name offset 302 uar t line control 0x0000.0000 r/w uar tlcrh 0x02c 304 uar t control 0x0000.0300 r/w uar tctl 0x030 306 uar t interrupt fifo level select 0x0000.0012 r/w uar tifls 0x034 307 uar t interrupt mask 0x0000.0000 r/w uar tim 0x038 309 uar t raw interrupt status 0x0000.000f ro uar tris 0x03c 310 uar t masked interrupt status 0x0000.0000 ro uar tmis 0x040 311 uar t interrupt clear 0x0000.0000 w1c uar ticr 0x044 313 uar t peripheral identification 4 0x0000.0000 ro uar tperiphid4 0xfd0 314 uar t peripheral identification 5 0x0000.0000 ro uar tperiphid5 0xfd4 315 uar t peripheral identification 6 0x0000.0000 ro uar tperiphid6 0xfd8 316 uar t peripheral identification 7 0x0000.0000 ro uar tperiphid7 0xfdc 317 uar t peripheral identification 0 0x0000.001 1 ro uar tperiphid0 0xfe0 318 uar t peripheral identification 1 0x0000.0000 ro uar tperiphid1 0xfe4 319 uar t peripheral identification 2 0x0000.0018 ro uar tperiphid2 0xfe8 320 uar t peripheral identification 3 0x0000.0001 ro uar tperiphid3 0xfec 321 uar t primecell identification 0 0x0000.000d ro uar tpcellid0 0xff0 322 uar t primecell identification 1 0x0000.00f0 ro uar tpcellid1 0xff4 323 uar t primecell identification 2 0x0000.0005 ro uar tpcellid2 0xff8 324 uar t primecell identification 3 0x0000.00b1 ro uar tpcellid3 0xffc 13.5 register descriptions the remainder of this section lists and describes the uar t registers, in numerical order by address of fset. june 14, 2007 292 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 1: uart data (uartdr), offset 0x000 this register is the data register (the interface to the fifos). when fifos are enabled, data written to this location is pushed onto the transmit fifo. if fifos are disabled, data is stored in the transmitter holding register (the bottom word of the transmit fifo). a write to this register initiates a transmission from the uar t . for received data, if the fifo is enabled, the data byte and the 4-bit status (break, frame, parity and overrun) is pushed onto the 12-bit wide receive fifo. if fifos are disabled, the data byte and status are stored in the receiving holding register (the bottom word of the receive fifo). the received data can be retrieved by reading this register . uar t data (uar tdr) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x000 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a fe pe be oe reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:12 uar t overrun error 1=new data was received when the fifo was full, resulting in data loss. 0=there has been no data loss due to a fifo overrun. 0 ro oe 1 1 uar t break error this bit is set to 1 when a break condition is detected, indicating that the receive data input was held low for longer than a full-word transmission time (defined as start, data, parity , and stop bits). in fifo mode, this error is associated with the character at the top of the fifo. when a break occurs, only one 0 character is loaded into the fifo. the next character is only enabled after the received data input goes to a 1 (marking state) and the next valid start bit is received. 0 ro be 10 uar t parity error this bit is set to 1 when the parity of the received data character does not match the parity defined by bits 2 and 7 of the uartlcrh register . in fifo mode, this error is associated with the character at the top of the fifo. 0 ro pe 9 293 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field uar t framing error this bit is set to 1 when the received character does not have a valid stop bit (a valid stop bit is 1). 0 ro fe 8 when written, the data that is to be transmitted via the uar t . when read, the data that was received by the uar t . 0 r/w da t a 7:0 june 14, 2007 294 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 2: uart receive status/error clear (uartrsr/uartecr), offset 0x004 the uartrsr/uartecr register is the receive status register/error clear register . in addition to the uartdr register , receive status can also be read from the uartrsr register . if the status is read from this register , then the status information corresponds to the entry read from uartdr prior to reading uartrsr . the status information for overrun is set immediately when an overrun condition occurs. a write of any value to the uartecr register clears the framing, parity , break, and overrun errors. all the bits are cleared to 0 on reset. read-only receive status (uartrsr) register uar t receive status/error clear (uar trsr/uar tecr) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x004 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 fe pe be oe reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. the uartrsr register cannot be written. 0 ro reserved 31:4 uar t overrun error when this bit is set to 1, data is received and the fifo is already full. this bit is cleared to 0 by a write to uartecr . the fifo contents remain valid since no further data is written when the fifo is full, only the contents of the shift register are overwritten. the cpu must now read the data in order to empty the fifo. 0 ro oe 3 uar t break error this bit is set to 1 when a break condition is detected, indicating that the received data input was held low for longer than a full-word transmission time (defined as start, data, parity , and stop bits). this bit is cleared to 0 by a write to uartecr . in fifo mode, this error is associated with the character at the top of the fifo. when a break occurs, only one 0 character is loaded into the fifo. the next character is only enabled after the receive data input goes to a 1 (marking state) and the next valid start bit is received. 0 ro be 2 295 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field uar t parity error this bit is set to 1 when the parity of the received data character does not match the parity defined by bits 2 and 7 of the uartlcrh register . this bit is cleared to 0 by a write to uartecr . 0 ro pe 1 uar t framing error this bit is set to 1 when the received character does not have a valid stop bit (a valid stop bit is 1). this bit is cleared to 0 by a write to uartecr . in fifo mode, this error is associated with the character at the top of the fifo. 0 ro fe 0 w rite-only error clear (uartecr) register uar t receive status/error clear (uar trsr/uar tecr) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x004 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a reserved wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo wo t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 wo reserved 31:8 a write to this register of any data clears the framing, parity , break and overrun flags. 0 wo da t a 7:0 june 14, 2007 296 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 3: uart flag (uartfr), offset 0x018 the uartfr register is the flag register . after reset, the txff , rxff , and busy bits are 0, and txfe and rxfe bits are 1. uar t flag (uar tfr) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x018 t ype ro, reset 0x0000.0090 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved busy rxfe txff rxff txfe reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t t ransmit fifo empty the meaning of this bit depends on the state of the fen bit in the uartlcrh register . if the fifo is disabled ( fen is 0), this bit is set when the transmit holding register is empty . if the fifo is enabled ( fen is 1), this bit is set when the transmit fifo is empty . 1 ro txfe 7 uar t receive fifo full the meaning of this bit depends on the state of the fen bit in the uartlcrh register . if the fifo is disabled, this bit is set when the receive holding register is full. if the fifo is enabled, this bit is set when the receive fifo is full. 0 ro rxff 6 uar t t ransmit fifo full the meaning of this bit depends on the state of the fen bit in the uartlcrh register . if the fifo is disabled, this bit is set when the transmit holding register is full. if the fifo is enabled, this bit is set when the transmit fifo is full. 0 ro txff 5 297 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field uar t receive fifo empty the meaning of this bit depends on the state of the fen bit in the uartlcrh register . if the fifo is disabled, this bit is set when the receive holding register is empty . if the fifo is enabled, this bit is set when the receive fifo is empty . 1 ro rxfe 4 uar t busy when this bit is 1, the uar t is busy transmitting data. this bit remains set until the complete byte, including all stop bits, has been sent from the shift register . this bit is set as soon as the transmit fifo becomes non-empty (regardless of whether uar t is enabled). 0 ro busy 3 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 2:0 june 14, 2007 298 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 4: uart irda low-power register (uartilpr), offset 0x020 the uartilpr register is an 8-bit read/write register that stores the low-power counter divisor value used to generate the irlpbaud16 signal by dividing down the system clock (sysclk). all the bits are cleared to 0 when reset. the irlpbaud16 internal signal is generated by dividing down the uartclk signal according to the low-power divisor value written to uartilpr . the low-power divisor value is calculated as follows: ilpdvsr = sysclk / f irlpbaud16 where f irlpbaud16 is nominally 1.8432 mhz. irlpbaud16 is an internal signal used for sir pulse generation when low-power mode is used. y ou must choose the divisor so that 1.42 mhz < f irlpbaud16 < 2.12 mhz, which results in a low-power pulse duration of 1.41C2.1 1 s (three times the period of irlpbaud16 ). the minimum frequency of irlpbaud16 ensures that pulses less than one period of irlpbaud16 are rejected, but that pulses greater than 1.4 s are accepted as valid pulses. note: zero is an illegal value. programming a zero value results in no irlpbaud16 pulses being generated. uar t irda low-power register (uar tilpr) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x020 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ilpdvsr reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 irda low-power divisor this is an 8-bit low-power divisor value. 0x0000 r/w ilpdvsr 7:0 299 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: uart integer baud-rate divisor (uartibrd), offset 0x024 the uartibrd register is the integer part of the baud-rate divisor value. all the bits are cleared on reset. the minimum possible divide ratio is 1 (when uartibrd =0), in which case the uartfbrd register is ignored. when changing the uartibrd register , the new value does not take ef fect until transmission/reception of the current character is complete. any changes to the baud-rate divisor must be followed by a write to the uartlcrh register . see baud-rate generation on page 287 for configuration details. uar t integer baud-rate divisor (uar tibrd) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x024 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 divint r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 integer baud-rate divisor 0x0000 r/w divint 15:0 june 14, 2007 300 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 6: uart fractional baud-rate divisor (uartfbrd), offset 0x028 the uartfbrd register is the fractional part of the baud-rate divisor value. all the bits are cleared on reset. when changing the uartfbrd register , the new value does not take ef fect until transmission/reception of the current character is complete. any changes to the baud-rate divisor must be followed by a write to the uartlcrh register . see baud-rate generation on page 287 for configuration details. uar t fractional baud-rate divisor (uar tfbrd) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x028 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 divfrac reserved r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:6 fractional baud-rate divisor 0x00 r/w divfrac 5:0 301 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: uart line control (uartlcrh), offset 0x02c the uartlcrh register is the line control register . serial parameters such as data length, parity and stop bit selection are implemented in this register . when updating the baud-rate divisor ( uartibrd and/or uartifrd ), the uartlcrh register must also be written. the write strobe for the baud-rate divisor registers is tied to the uartlcrh register . uar t line control (uar tlcrh) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x02c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 brk pen eps stp2 fen wlen sps reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t stick parity select when bits 1, 2 and 7 of uartlcrh are set, the parity bit is transmitted and checked as a 0. when bits 1 and 7 are set and 2 is cleared, the parity bit is transmitted and checked as a 1. when this bit is cleared, stick parity is disabled. 0 r/w sps 7 uar t w ord length the bits indicate the number of data bits transmitted or received in a frame as follows: 0x3: 8 bits 0x2: 7 bits 0x1: 6 bits 0x0: 5 bits (default) 0 r/w wlen 6:5 uar t enable fifos if this bit is set to 1, transmit and receive fifo buf fers are enabled (fifo mode). when cleared to 0, fifos are disabled (character mode). the fifos become 1-byte-deep holding registers. 0 r/w fen 4 uar t t wo stop bits select if this bit is set to 1, two stop bits are transmitted at the end of a frame. the receive logic does not check for two stop bits being received. 0 r/w stp2 3 june 14, 2007 302 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
description reset t ype name bit/field uar t even parity select if this bit is set to 1, even parity generation and checking is performed during transmission and reception, which checks for an even number of 1s in data and parity bits. when cleared to 0, then odd parity is performed, which checks for an odd number of 1s. this bit has no ef fect when parity is disabled by the pen bit. 0 r/w eps 2 uar t parity enable if this bit is set to 1, parity checking and generation is enabled; otherwise, parity is disabled and no parity bit is added to the data frame. 0 r/w pen 1 uar t send break if this bit is set to 1, a low level is continually output on the untx output, after completing transmission of the current character . for the proper execution of the break command, the software must set this bit for at least two frames (character periods). for normal use, this bit must be cleared to 0. 0 r/w brk 0 303 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 8: uart control (uartctl), offset 0x030 the uartctl register is the control register . all the bits are cleared on reset except for the transmit enable (txe) and receive enable (rxe) bits, which are set to 1. t o enable the uar t module, the uarten bit must be set to 1. if software requires a configuration change in the module, the uarten bit must be cleared before the configuration changes are written. if the uar t is disabled during a transmit or receive operation, the current transaction is completed prior to the uar t stopping. uar t control (uar tctl) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x030 t ype r/w , reset 0x0000.0300 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 uar ten siren sirlp reserved lbe txe rxe reserved r/w r/w r/w ro ro ro ro r/w r/w r/w ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:10 uar t receive enable if this bit is set to 1, the receive section of the uar t is enabled. when the uar t is disabled in the middle of a receive, it completes the current character before stopping. note: t o enable reception, the uarten bit must also be set. 1 r/w rxe 9 uar t t ransmit enable if this bit is set to 1, the transmit section of the uar t is enabled. when the uar t is disabled in the middle of a transmission, it completes the current character before stopping. note: t o enable transmission, the uarten bit must also be set. 1 r/w txe 8 uar t loop back enable if this bit is set to 1, the untx path is fed through the unrx path. 0 r/w lbe 7 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 6:3 june 14, 2007 304 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
description reset t ype name bit/field uar t sir low power mode this bit selects the irda encoding mode. if this bit is cleared to 0, low-level bits are transmitted as an active high pulse with a width of 3/16th of the bit period. if this bit is set to 1, low-level bits are transmitted with a pulse width which is 3 times the period of the irlpbaud16 input signal, regardless of the selected bit rate. setting this bit uses less power , but might reduce transmission distances. see page 299 for more information. 0 r/w sirlp 2 uar t sir enable if this bit is set to 1, the irda sir block is enabled, and the uar t will transmit and receive data using sir protocol. 0 r/w siren 1 uar t enable if this bit is set to 1, the uar t is enabled. when the uar t is disabled in the middle of transmission or reception, it completes the current character before stopping. 0 r/w uar ten 0 305 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 9: uart interrupt fifo level select (uartifls), offset 0x034 the uartifls register is the interrupt fifo level select register . y ou can use this register to define the fifo level at which the txris and rxris bits in the uartris register are triggered. the interrupts are generated based on a transition through a level rather than being based on the level. that is, the interrupts are generated when the fill level progresses through the trigger level. for example, if the receive trigger level is set to the half-way mark, the interrupt is triggered as the module is receiving the 9th character . out of reset, the txiflsel and rxiflsel bits are configured so that the fifos trigger an interrupt at the half-way mark. uar t interrupt fifo level select (uar tifls) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x034 t ype r/w , reset 0x0000.0012 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 txiflsel rxiflsel reserved r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro t ype 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:6 uar t receive interrupt fifo level select the trigger points for the receive interrupt are as follows: 000: rx fifo 1/8 full 001: rx fifo ? full 010: rx fifo ? full (default) 01 1: rx fifo ? full 100: rx fifo 7/8 full 101-1 1 1: reserved 0x2 r/w rxiflsel 5:3 uar t t ransmit interrupt fifo level select the trigger points for the transmit interrupt are as follows: 000: tx fifo 1/8 full 001: tx fifo ? full 010: tx fifo ? full (default) 01 1: tx fifo ? full 100: tx fifo 7/8 full 101-1 1 1: reserved 0x2 r/w txiflsel 2:0 june 14, 2007 306 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 10: uart interrupt mask (uartim), offset 0x038 the uartim register is the interrupt mask set/clear register . on a read, this register gives the current value of the mask on the relevant interrupt. w riting a 1 to a bit allows the corresponding raw interrupt signal to be routed to the interrupt controller . w riting a 0 prevents the raw interrupt signal from being sent to the interrupt controller . uar t interrupt mask (uar tim) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x038 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved rxim txim r tim feim peim beim oeim reserved ro ro ro ro r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 1 uar t overrun error interrupt mask on a read, the current mask for the oeim interrupt is returned. setting this bit to 1 promotes the oeim interrupt to the interrupt controller . 0 r/w oeim 10 uar t break error interrupt mask on a read, the current mask for the beim interrupt is returned. setting this bit to 1 promotes the beim interrupt to the interrupt controller . 0 r/w beim 9 uar t parity error interrupt mask on a read, the current mask for the peim interrupt is returned. setting this bit to 1 promotes the peim interrupt to the interrupt controller . 0 r/w peim 8 uar t framing error interrupt mask on a read, the current mask for the feim interrupt is returned. setting this bit to 1 promotes the feim interrupt to the interrupt controller . 0 r/w feim 7 uar t receive t ime-out interrupt mask on a read, the current mask for the rtim interrupt is returned. setting this bit to 1 promotes the rtim interrupt to the interrupt controller . 0 r/w r tim 6 uar t t ransmit interrupt mask on a read, the current mask for the txim interrupt is returned. setting this bit to 1 promotes the txim interrupt to the interrupt controller . 0 r/w txim 5 307 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field uar t receive interrupt mask on a read, the current mask for the rxim interrupt is returned. setting this bit to 1 promotes the rxim interrupt to the interrupt controller . 0 r/w rxim 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3:0 june 14, 2007 308 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 1 1: uart raw interrupt status (uartris), offset 0x03c the uartris register is the raw interrupt status register . on a read, this register gives the current raw status value of the corresponding interrupt. a write has no ef fect. uar t raw interrupt status (uar tris) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x03c t ype ro, reset 0x0000.000f 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved rxris txris r tris feris peris beris oeris reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 1 uar t overrun error raw interrupt status gives the raw interrupt state (prior to masking) of this interrupt. 0 ro oeris 10 uar t break error raw interrupt status gives the raw interrupt state (prior to masking) of this interrupt. 0 ro beris 9 uar t parity error raw interrupt status gives the raw interrupt state (prior to masking) of this interrupt. 0 ro peris 8 uar t framing error raw interrupt status gives the raw interrupt state (prior to masking) of this interrupt. 0 ro feris 7 uar t receive t ime-out raw interrupt status gives the raw interrupt state (prior to masking) of this interrupt. 0 ro r tris 6 uar t t ransmit raw interrupt status gives the raw interrupt state (prior to masking) of this interrupt. 0 ro txris 5 uar t receive raw interrupt status gives the raw interrupt state (prior to masking) of this interrupt. 0 ro rxris 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0xf ro reserved 3:0 309 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 12: uart masked interrupt status (uartmis), offset 0x040 the uartmis register is the masked interrupt status register . on a read, this register gives the current masked status value of the corresponding interrupt. a write has no ef fect. uar t masked interrupt status (uar tmis) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x040 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved rxmis txmis r tmis femis pemis bemis oemis reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 1 uar t overrun error masked interrupt status gives the masked interrupt state of this interrupt. 0 ro oemis 10 uar t break error masked interrupt status gives the masked interrupt state of this interrupt. 0 ro bemis 9 uar t parity error masked interrupt status gives the masked interrupt state of this interrupt. 0 ro pemis 8 uar t framing error masked interrupt status gives the masked interrupt state of this interrupt. 0 ro femis 7 uar t receive t ime-out masked interrupt status gives the masked interrupt state of this interrupt. 0 ro r tmis 6 uar t t ransmit masked interrupt status gives the masked interrupt state of this interrupt. 0 ro txmis 5 uar t receive masked interrupt status gives the masked interrupt state of this interrupt. 0 ro rxmis 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3:0 june 14, 2007 310 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 13: uart interrupt clear (uarticr), offset 0x044 the uarticr register is the interrupt clear register . on a write of 1, the corresponding interrupt (both raw interrupt and masked interrupt, if enabled) is cleared. a write of 0 has no ef fect. uar t interrupt clear (uar ticr) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0x044 t ype w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved rxic txic r tic feic peic beic oeic reserved ro ro ro ro w1c w1c w1c w1c w1c w1c w1c ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 1 overrun error interrupt clear 0: no ef fect on the interrupt. 1: clears interrupt. 0 w1c oeic 10 break error interrupt clear 0: no ef fect on the interrupt. 1: clears interrupt. 0 w1c beic 9 parity error interrupt clear 0: no ef fect on the interrupt. 1: clears interrupt. 0 w1c peic 8 framing error interrupt clear 0: no ef fect on the interrupt. 1: clears interrupt. 0 w1c feic 7 receive t ime-out interrupt clear 0: no ef fect on the interrupt. 1: clears interrupt. 0 w1c r tic 6 t ransmit interrupt clear 0: no ef fect on the interrupt. 1: clears interrupt. 0 w1c txic 5 31 1 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field receive interrupt clear 0: no ef fect on the interrupt. 1: clears interrupt. 0 w1c rxic 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3:0 june 14, 2007 312 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 14: uart peripheral identification 4 (uartperiphid4), offset 0xfd0 the uartperiphidn registers are hard-coded and the fields within the registers determine the reset values. uar t peripheral identification 4 (uar tperiphid4) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xfd0 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid4 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t peripheral id register[7:0] 0x00 ro pid4 7:0 313 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 15: uart peripheral identification 5 (uartperiphid5), offset 0xfd4 the uartperiphidn registers are hard-coded and the fields within the registers determine the reset values. uar t peripheral identification 5 (uar tperiphid5) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xfd4 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid5 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t peripheral id register[15:8] 0x00 ro pid5 7:0 june 14, 2007 314 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 16: uart peripheral identification 6 (uartperiphid6), offset 0xfd8 the uartperiphidn registers are hard-coded and the fields within the registers determine the reset values. uar t peripheral identification 6 (uar tperiphid6) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xfd8 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid6 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t peripheral id register[23:16] 0x00 ro pid6 7:0 315 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 17: uart peripheral identification 7 (uartperiphid7), offset 0xfdc the uartperiphidn registers are hard-coded and the fields within the registers determine the reset values. uar t peripheral identification 7 (uar tperiphid7) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xfdc t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid7 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t peripheral id register[31:24] 0x00 ro pid7 7:0 june 14, 2007 316 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 18: uart peripheral identification 0 (uartperiphid0), offset 0xfe0 the uartperiphidn registers are hard-coded and the fields within the registers determine the reset values. uar t peripheral identification 0 (uar tperiphid0) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xfe0 t ype ro, reset 0x0000.001 1 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t peripheral id register[7:0] can be used by software to identify the presence of this peripheral. 0x1 1 ro pid0 7:0 317 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 19: uart peripheral identification 1 (uartperiphid1), offset 0xfe4 the uartperiphidn registers are hard-coded and the fields within the registers determine the reset values. uar t peripheral identification 1 (uar tperiphid1) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xfe4 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t peripheral id register[15:8] can be used by software to identify the presence of this peripheral. 0x00 ro pid1 7:0 june 14, 2007 318 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 20: uart peripheral identification 2 (uartperiphid2), offset 0xfe8 the uartperiphidn registers are hard-coded and the fields within the registers determine the reset values. uar t peripheral identification 2 (uar tperiphid2) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xfe8 t ype ro, reset 0x0000.0018 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t peripheral id register[23:16] can be used by software to identify the presence of this peripheral. 0x18 ro pid2 7:0 319 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 21: uart peripheral identification 3 (uartperiphid3), offset 0xfec the uartperiphidn registers are hard-coded and the fields within the registers determine the reset values. uar t peripheral identification 3 (uar tperiphid3) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xfec t ype ro, reset 0x0000.0001 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t peripheral id register[31:24] can be used by software to identify the presence of this peripheral. 0x01 ro pid3 7:0 june 14, 2007 320 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 22: uart primecell identification 0 (uartpcellid0), offset 0xff0 the uartpcellidn registers are hard-coded and the fields within the registers determine the reset values. uar t primecell identification 0 (uar tpcellid0) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xff0 t ype ro, reset 0x0000.000d 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t primecell id register[7:0] provides software a standard cross-peripheral identification system. 0x0d ro cid0 7:0 321 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 23: uart primecell identification 1 (uartpcellid1), offset 0xff4 the uartpcellidn registers are hard-coded and the fields within the registers determine the reset values. uar t primecell identification 1 (uar tpcellid1) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xff4 t ype ro, reset 0x0000.00f0 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t primecell id register[15:8] provides software a standard cross-peripheral identification system. 0xf0 ro cid1 7:0 june 14, 2007 322 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
register 24: uart primecell identification 2 (uartpcellid2), offset 0xff8 the uartpcellidn registers are hard-coded and the fields within the registers determine the reset values. uar t primecell identification 2 (uar tpcellid2) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xff8 t ype ro, reset 0x0000.0005 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t primecell id register[23:16] provides software a standard cross-peripheral identification system. 0x05 ro cid2 7:0 323 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 25: uart primecell identification 3 (uartpcellid3), offset 0xffc the uartpcellidn registers are hard-coded and the fields within the registers determine the reset values. uar t primecell identification 3 (uar tpcellid3) uar t0 base: 0x4000.c000 uar t1 base: 0x4000.d000 uar t2 base: 0x4000.e000 of fset 0xffc t ype ro, reset 0x0000.00b1 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 1 1 0 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 uar t primecell id register[31:24] provides software a standard cross-peripheral identification system. 0xb1 ro cid3 7:0 june 14, 2007 324 luminary micro confidential-advance product information universal asynchronous receivers/t ransmitters (uar t s)
14 synchronous serial interface (ssi) ssi the stellaris ? synchronous serial interface (ssi) is a master or slave interface for synchronous serial communication with peripheral devices that have either freescale spi, microwire, or t exas instruments synchronous serial interfaces. the stellaris ? ssi module has the following features: master or slave operation programmable clock bit rate and prescale separate transmit and receive fifos, 16 bits wide, 8 locations deep programmable interface operation for freescale spi, microwire, or t exas instruments synchronous serial interfaces programmable data frame size from 4 to 16 bits internal loopback test mode for diagnostic/debug testing 14.1 block diagram figure 14-1. ssi module block diagram 325 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller t ransmit / receive logic clock prescaler ssicpsr control / status ssicr 0 ssicr 1 ssisr interrupt control ssiim ssimis ssiris ssiicr ssidr txfifo 8 x 16 . . . rxfifo 8 x 16 . . . system clock ssitx ssirx ssiclk ssifss interrupt identification registers ssipcellid 0 ssiperiphid 0 ssiperiphid 4 ssipcellid 1 ssiperiphid 1 ssiperiphid 5 ssipcellid 2 ssiperiphid 2 ssiperiphid 6 ssipcellid 3 ssiperiphid 3 ssiperiphid 7
14.2 functional description the ssi performs serial-to-parallel conversion on data received from a peripheral device. the cpu accesses data, control, and status information. the transmit and receive paths are buf fered with internal fifo memories allowing up to eight 16-bit values to be stored independently in both transmit and receive modes. 14.2.1 bit rate generation the ssi includes a programmable bit rate clock divider and prescaler to generate the serial output clock. bit rates are supported to 2 mhz and higher , although maximum bit rate is determined by peripheral devices. the serial bit rate is derived by dividing down the 50-mhz input clock. the clock is first divided by an even prescale value cpsdvsr from 2 to 254, which is programmed in the ssi clock prescale (ssicpsr) register (see page 342 ). the clock is further divided by a value from 1 to 256, which is 1 + scr , where scr is the value programmed in the ssi control0 (ssicr0) register (see page 337 ). the frequency of the output clock ssiclk is defined by: fssiclk = fsysclk / (cpsdvsr * (1 + scr)) note that although the ssiclk transmit clock can theoretically be 25 mhz, the module may not be able to operate at that speed. for master mode, the system clock must be at least two times faster than the ssiclk . for slave mode, the system clock must be at least 12 times faster than the ssiclk . see electrical characteristics on page 511 to view ssi timing parameters. 14.2.2 fifo operation 14.2.2.1 t ransmit fifo the common transmit fifo is a 16-bit wide, 8-locations deep, first-in, first-out memory buf fer . the cpu writes data to the fifo by writing the ssi data (ssidr) register (see page 340 ), and data is stored in the fifo until it is read out by the transmission logic. when configured as a master or a slave, parallel data is written into the transmit fifo prior to serial conversion and transmission to the attached slave or master , respectively , through the ssitx pin. 14.2.2.2 receive fifo the common receive fifo is a 16-bit wide, 8-locations deep, first-in, first-out memory buf fer . received data from the serial interface is stored in the buf fer until read out by the cpu, which accesses the read fifo by reading the ssidr register . when configured as a master or slave, serial data received through the ssirx pin is registered prior to parallel loading into the attached slave or master receive fifo, respectively . 14.2.3 interrupts the ssi can generate interrupts when the following conditions are observed: t ransmit fifo service receive fifo service receive fifo time-out june 14, 2007 326 luminary micro confidential-advance product information synchronous serial interface (ssi)
receive fifo overrun all of the interrupt events are ored together before being sent to the interrupt controller , so the ssi can only generate a single interrupt request to the controller at any given time. y ou can mask each of the four individual maskable interrupts by setting the appropriate bits in the ssi interrupt mask (ssiim) register (see page 343 ). setting the appropriate mask bit to 1 enables the interrupt. provision of the individual outputs, as well as a combined interrupt output, allows use of either a global interrupt service routine, or modular device drivers to handle interrupts. the transmit and receive dynamic dataflow interrupts have been separated from the status interrupts so that data can be read or written in response to the fifo trigger levels. the status of the individual interrupt sources can be read from the ssi raw interrupt status (ssiris) and ssi masked interrupt status (ssimis) registers (see page 344 and page 345 , respectively). 14.2.4 frame formats each data frame is between 4 and 16 bits long, depending on the size of data programmed, and is transmitted starting with the msb. there are three basic frame types that can be selected: t exas instruments synchronous serial freescale spi microwire for all three formats, the serial clock ( ssiclk ) is held inactive while the ssi is idle, and ssiclk transitions at the programmed frequency only during active transmission or reception of data. the idle state of ssiclk is utilized to provide a receive timeout indication that occurs when the receive fifo still contains data after a timeout period. for freescale spi and microwire frame formats, the serial frame ( ssifss ) pin is active low , and is asserted (pulled down) during the entire transmission of the frame. for t exas instruments synchronous serial frame format, the ssifss pin is pulsed for one serial clock period starting at its rising edge, prior to the transmission of each frame. for this frame format, both the ssi and the of f-chip slave device drive their output data on the rising edge of ssiclk , and latch data from the other device on the falling edge. unlike the full-duplex transmission of the other two frame formats, the microwire format uses a special master-slave messaging technique, which operates at half-duplex. in this mode, when a frame begins, an 8-bit control message is transmitted to the of f-chip slave. during this transmit, no incoming data is received by the ssi. after the message has been sent, the of f-chip slave decodes it and, after waiting one serial clock after the last bit of the 8-bit control message has been sent, responds with the requested data. the returned data can be 4 to 16 bits in length, making the total frame length anywhere from 13 to 25 bits. 14.2.4.1 t exas instruments synchronous serial frame format figure 14-2 on page 328 shows the t exas instruments synchronous serial frame format for a single transmitted frame. 327 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
figure 14-2. ti synchronous serial frame format (single t ransfer) in this mode, ssiclk and ssifss are forced low , and the transmit data line ssitx is tristated whenever the ssi is idle. once the bottom entry of the transmit fifo contains data, ssifss is pulsed high for one ssiclk period. the value to be transmitted is also transferred from the transmit fifo to the serial shift register of the transmit logic. on the next rising edge of ssiclk , the msb of the 4 to 16-bit data frame is shifted out on the ssitx pin. likewise, the msb of the received data is shifted onto the ssirx pin by the of f-chip serial slave device. both the ssi and the of f-chip serial slave device then clock each data bit into their serial shifter on the falling edge of each ssiclk . the received data is transferred from the serial shifter to the receive fifo on the first rising edge of ssiclk after the lsb has been latched. figure 14-3 on page 328 shows the t exas instruments synchronous serial frame format when back-to-back frames are transmitted. figure 14-3. ti synchronous serial frame format (continuous t ransfer) 14.2.4.2 freescale spi frame format the freescale spi interface is a four-wire interface where the ssifss signal behaves as a slave select. the main feature of the freescale spi format is that the inactive state and phase of the ssiclk signal are programmable through the spo and sph bits within the ssiscr0 control register . spo clock polarity bit when the spo clock polarity control bit is low , it produces a steady state low value on the ssiclk pin. if the spo bit is high, a steady state high value is placed on the ssiclk pin when data is not being transferred. sph phase control bit the sph phase control bit selects the clock edge that captures data and allows it to change state. it has the most impact on the first bit transmitted by either allowing or not allowing a clock transition before the first data capture edge. when the sph phase control bit is low , data is captured on the first clock edge transition. if the sph bit is high, data is captured on the second clock edge transition. june 14, 2007 328 luminary micro confidential-advance product information synchronous serial interface (ssi) m s b l s b 4 t o 1 6 b i t s s s i c l k s s i f s s s s i t x / s s i r x s s i c l k 4 t o 1 6 b i t s s s i f s s s s i t x / s s i r x m s b l s b
14.2.4.3 freescale spi frame format with spo=0 and sph=0 single and continuous transmission signal sequences for freescale spi format with spo=0 and sph=0 are shown in figure 14-4 on page 329 and figure 14-5 on page 329 . figure 14-4. freescale spi format (single t ransfer) with spo=0 and sph=0 figure 14-5. freescale spi format (continuous t ransfer) with spo=0 and sph=0 note: q is undefined. in this configuration, during idle periods: ssiclk is forced low ssifss is forced high the transmit data line ssitx is arbitrarily forced low when the ssi is configured as a master , it enables the ssiclk pad when the ssi is configured as a slave, it disables the ssiclk pad if the ssi is enabled and there is valid data within the transmit fifo, the start of transmission is signified by the ssifss master signal being driven low . this causes slave data to be enabled onto the ssirx input line of the master . the master ssitx output pad is enabled. one half ssiclk period later , valid master data is transferred to the ssitx pin. now that both the master and slave data have been set, the ssiclk master clock pin goes high after one further half ssiclk period. the data is now captured on the rising and propagated on the falling edges of the ssiclk signal. in the case of a single word transmission, after all bits of the data word have been transferred, the ssifss line is returned to its idle high state one ssiclk period after the last bit has been captured. however , in the case of continuous back-to-back transmissions, the ssifss signal must be pulsed high between each data word transfer . this is because the slave select pin freezes the data in its 329 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller 4 t o 1 6 b i t s s s i c l k s s i f s s s s i r x q s s i t x m s b m s b l s b l s b s s i c l k s s i f s s s s i r x l s b s s i t x m s b l s b 4 t o 1 6 b i t s l s b m s b m s b m s b l s b
serial peripheral register and does not allow it to be altered if the sph bit is logic zero. therefore, the master device must raise the ssifss pin of the slave device between each data transfer to enable the serial peripheral data write. on completion of the continuous transfer , the ssifss pin is returned to its idle state one ssiclk period after the last bit has been captured. 14.2.4.4 freescale spi frame format with spo=0 and sph=1 the transfer signal sequence for freescale spi format with spo=0 and sph=1 is shown in figure 14-6 on page 330 , which covers both single and continuous transfers. figure 14-6. freescale spi frame format with spo=0 and sph=1 note: q is undefined. in this configuration, during idle periods: ssiclk is forced low ssifss is forced high the transmit data line ssitx is arbitrarily forced low when the ssi is configured as a master , it enables the ssiclk pad when the ssi is configured as a slave, it disables the ssiclk pad if the ssi is enabled and there is valid data within the transmit fifo, the start of transmission is signified by the ssifss master signal being driven low . the master ssitx output is enabled. after a further one half ssiclk period, both master and slave valid data is enabled onto their respective transmission lines. at the same time, the ssiclk is enabled with a rising edge transition. data is then captured on the falling edges and propagated on the rising edges of the ssiclk signal. in the case of a single word transfer , after all bits have been transferred, the ssifss line is returned to its idle high state one ssiclk period after the last bit has been captured. for continuous back-to-back transfers, the ssifss pin is held low between successive data words and termination is the same as that of the single word transfer . 14.2.4.5 freescale spi frame format with spo=1 and sph=0 single and continuous transmission signal sequences for freescale spi format with spo=1 and sph=0 are shown in figure 14-7 on page 331 and figure 14-8 on page 331 . june 14, 2007 330 luminary micro confidential-advance product information synchronous serial interface (ssi) 4 t o 1 6 b i t s s s i c l k s s i f s s s s i r x s s i t x q m s b q m s b l s b l s b
figure 14-7. freescale spi frame format (single t ransfer) with spo=1 and sph=0 note: q is undefined. figure 14-8. freescale spi frame format (continuous t ransfer) with spo=1 and sph=0 in this configuration, during idle periods: ssiclk is forced high ssifss is forced high the transmit data line ssitx is arbitrarily forced low when the ssi is configured as a master , it enables the ssiclk pad when the ssi is configured as a slave, it disables the ssiclk pad if the ssi is enabled and there is valid data within the transmit fifo, the start of transmission is signified by the ssifss master signal being driven low , which causes slave data to be immediately transferred onto the ssirx line of the master . the master ssitx output pad is enabled. one half period later , valid master data is transferred to the ssitx line. now that both the master and slave data have been set, the ssiclk master clock pin becomes low after one further half ssiclk period. this means that data is captured on the falling edges and propagated on the rising edges of the ssiclk signal. in the case of a single word transmission, after all bits of the data word are transferred, the ssifss line is returned to its idle high state one ssiclk period after the last bit has been captured. however , in the case of continuous back-to-back transmissions, the ssifss signal must be pulsed high between each data word transfer . this is because the slave select pin freezes the data in its serial peripheral register and does not allow it to be altered if the sph bit is logic zero. therefore, the master device must raise the ssifss pin of the slave device between each data transfer to enable the serial peripheral data write. on completion of the continuous transfer , the ssifss pin is returned to its idle state one ssiclk period after the last bit has been captured. 331 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller s s i c l k s s i f s s s s i t x / s s i r x m s b l s b 4 t o 1 6 b i t s l s b m s b 4 t o 1 6 b i t s s s i c l k s s i f s s s s i r x s s i t x q m s b m s b l s b l s b
14.2.4.6 freescale spi frame format with spo=1 and sph=1 the transfer signal sequence for freescale spi format with spo=1 and sph=1 is shown in figure 14-9 on page 332 , which covers both single and continuous transfers. figure 14-9. freescale spi frame format with spo=1 and sph=1 note: q is undefined. in this configuration, during idle periods: ssiclk is forced high ssifss is forced high the transmit data line ssitx is arbitrarily forced low when the ssi is configured as a master , it enables the ssiclk pad when the ssi is configured as a slave, it disables the ssiclk pad if the ssi is enabled and there is valid data within the transmit fifo, the start of transmission is signified by the ssifss master signal being driven low . the master ssitx output pad is enabled. after a further one-half ssiclk period, both master and slave data are enabled onto their respective transmission lines. at the same time, ssiclk is enabled with a falling edge transition. data is then captured on the rising edges and propagated on the falling edges of the ssiclk signal. after all bits have been transferred, in the case of a single word transmission, the ssifss line is returned to its idle high state one ssiclk period after the last bit has been captured. for continuous back-to-back transmissions, the ssifss pin remains in its active low state, until the final bit of the last word has been captured, and then returns to its idle state as described above. for continuous back-to-back transfers, the ssifss pin is held low between successive data words and termination is the same as that of the single word transfer . 14.2.4.7 microwire frame format figure 14-10 on page 333 shows the microwire frame format, again for a single frame. figure 14-1 1 on page 334 shows the same format when back-to-back frames are transmitted. june 14, 2007 332 luminary micro confidential-advance product information synchronous serial interface (ssi) 4 t o 1 6 b i t s s s i c l k s s i f s s s s i r x s s i t x q q m s b m s b l s b l s b
figure 14-10. microwire frame format (single frame) microwire format is very similar to spi format, except that transmission is half-duplex instead of full-duplex, using a master-slave message passing technique. each serial transmission begins with an 8-bit control word that is transmitted from the ssi to the of f-chip slave device. during this transmission, no incoming data is received by the ssi. after the message has been sent, the of f-chip slave decodes it and, after waiting one serial clock after the last bit of the 8-bit control message has been sent, responds with the required data. the returned data is 4 to 16 bits in length, making the total frame length anywhere from 13 to 25 bits. in this configuration, during idle periods: ssiclk is forced low ssifss is forced high the transmit data line ssitx is arbitrarily forced low a transmission is triggered by writing a control byte to the transmit fifo. the falling edge of ssifss causes the value contained in the bottom entry of the transmit fifo to be transferred to the serial shift register of the transmit logic, and the msb of the 8-bit control frame to be shifted out onto the ssitx pin. ssifss remains low for the duration of the frame transmission. the ssirx pin remains tristated during this transmission. the of f-chip serial slave device latches each control bit into its serial shifter on the rising edge of each ssiclk . after the last bit is latched by the slave device, the control byte is decoded during a one clock wait-state, and the slave responds by transmitting data back to the ssi. each bit is driven onto the ssirx line on the falling edge of ssiclk . the ssi in turn latches each bit on the rising edge of ssiclk . at the end of the frame, for single transfers, the ssifss signal is pulled high one clock period after the last bit has been latched in the receive serial shifter , which causes the data to be transferred to the receive fifo. note: the of f-chip slave device can tristate the receive line either on the falling edge of ssiclk after the lsb has been latched by the receive shifter , or when the ssifss pin goes high. for continuous transfers, data transmission begins and ends in the same manner as a single transfer . however , the ssifss line is continuously asserted (held low) and transmission of data occurs back-to-back. the control byte of the next frame follows directly after the lsb of the received data from the current frame. each of the received values is transferred from the receive shifter on the falling edge of ssiclk , after the lsb of the frame has been latched into the ssi. 333 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller s s i c l k s s i f s s l s b m s b s s i r x 4 t o 1 6 b i t s o u t p u t d a t a 0 s s i t x m s b l s b 8 - b i t c o n t r o l
figure 14-1 1. microwire frame format (continuous t ransfer) in the microwire mode, the ssi slave samples the first bit of receive data on the rising edge of ssiclk after ssifss has gone low . masters that drive a free-running ssiclk must ensure that the ssifss signal has suf ficient setup and hold margins with respect to the rising edge of ssiclk . figure 14-12 on page 334 illustrates these setup and hold time requirements. with respect to the ssiclk rising edge on which the first bit of receive data is to be sampled by the ssi slave, ssifss must have a setup of at least two times the period of ssiclk on which the ssi operates. with respect to the ssiclk rising edge previous to this edge, ssifss must have a hold of at least one ssiclk period. figure 14-12. microwire frame format, ssifss input setup and hold requirements 14.3 initialization and configuration t o use the ssi, its peripheral clock must be enabled by setting the ssi bit in the rcgc1 register . for each of the frame formats, the ssi is configured using the following steps: 1. ensure that the sse bit in the ssicr1 register is disabled before making any configuration changes. 2. select whether the ssi is a master or slave: a. for master operations, set the ssicr1 register to 0x00000000. b. for slave mode (output enabled), set the ssicr1 register to 0x00000004. c. for slave mode (output disabled), set the ssicr1 register to 0x0000000c. 3. configure the clock prescale divisor by writing the ssicpsr register . june 14, 2007 334 luminary micro confidential-advance product information synchronous serial interface (ssi) s s i c l k s s i f s s s s i r x f i r s t r x d a t a t o b e s a m p l e d b y s s i s l a v e t s e t u p = ( 2 * t s s i c l k ) t h o l d = t s s i c l k 8 - b i t c o n t r o l s s i c l k s s i f s s l s b m s b s s i r x 4 t o 1 6 b i t s o u t p u t d a t a 0 s s i t x m s b l s b l s b m s b
4. w rite the ssicr0 register with the following configuration: serial clock rate ( scr ) desired clock phase/polarity , if using freescale spi mode ( sph and spo ) the protocol mode: freescale spi, ti ssf , microwire ( frf ) the data size ( dss ) 5. enable the ssi by setting the sse bit in the ssicr1 register . as an example, assume the ssi must be configured to operate with the following parameters: master operation freescale spi mode (spo=1, sph=1) 1 mbps bit rate 8 data bits assuming the system clock is 20 mhz, the bit rate calculation would be: fssiclk = fsysclk / (cpsdvsr * (1 + scr)) 1x106 = 20x106 / (cpsdvsr * (1 + scr)) in this case, if cpsdvsr =2, scr must be 9. the configuration sequence would be as follows: 1. ensure that the sse bit in the ssicr1 register is disabled. 2. w rite the ssicr1 register with a value of 0x00000000. 3. w rite the ssicpsr register with a value of 0x00000002. 4. w rite the ssicr0 register with a value of 0x000009c7. 5. the ssi is then enabled by setting the sse bit in the ssicr1 register to 1. 14.4 register map t able 14-1 on page 335 lists the ssi registers. the of fset listed is a hexadecimal increment to the register s address, relative to that ssi module s base address: ssi0: 0x4000.8000 note: the ssi must be disabled (see the sse bit in the ssicr1 register) before any of the control registers are reprogrammed. t able 14-1. ssi register map see page description reset t ype name offset 337 ssi control 0 0x0000.0000 r/w ssicr0 0x000 335 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
see page description reset t ype name offset 339 ssi control 1 0x0000.0000 r/w ssicr1 0x004 340 ssi data 0x0000.0000 r/w ssidr 0x008 341 ssi status 0x0000.0003 ro ssisr 0x00c 342 ssi clock prescale 0x0000.0000 r/w ssicpsr 0x010 343 ssi interrupt mask 0x0000.0000 r/w ssiim 0x014 344 ssi raw interrupt status 0x0000.0008 ro ssiris 0x018 345 ssi masked interrupt status 0x0000.0000 ro ssimis 0x01c 346 ssi interrupt clear 0x0000.0000 w1c ssiicr 0x020 347 ssi peripheral identification 4 0x0000.0000 ro ssiperiphid4 0xfd0 348 ssi peripheral identification 5 0x0000.0000 ro ssiperiphid5 0xfd4 349 ssi peripheral identification 6 0x0000.0000 ro ssiperiphid6 0xfd8 350 ssi peripheral identification 7 0x0000.0000 ro ssiperiphid7 0xfdc 351 ssi peripheral identification 0 0x0000.0022 ro ssiperiphid0 0xfe0 352 ssi peripheral identification 1 0x0000.0000 ro ssiperiphid1 0xfe4 353 ssi peripheral identification 2 0x0000.0018 ro ssiperiphid2 0xfe8 354 ssi peripheral identification 3 0x0000.0001 ro ssiperiphid3 0xfec 355 ssi primecell identification 0 0x0000.000d ro ssipcellid0 0xff0 356 ssi primecell identification 1 0x0000.00f0 ro ssipcellid1 0xff4 357 ssi primecell identification 2 0x0000.0005 ro ssipcellid2 0xff8 358 ssi primecell identification 3 0x0000.00b1 ro ssipcellid3 0xffc 14.5 register descriptions the remainder of this section lists and describes the ssi registers, in numerical order by address of fset. june 14, 2007 336 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 1: ssi control 0 (ssicr0), offset 0x000 ssicr0 is control register 0 and contains bit fields that control various functions within the ssi module. functionality such as protocol mode, clock rate and data size are configured in this register . ssi control 0 (ssicr0) ssi0 base: 0x4000.8000 of fset 0x000 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 dss frf spo sph scr r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 ssi serial clock rate the value scr is used to generate the transmit and receive bit rate of the ssi. the bit rate is: br=fssiclk/(cpsdvsr * (1 + scr)) where cpsdvsr is an even value from 2-254 programmed in the ssicpsr register , and scr is a value from 0-255. 0 r/w scr 15:8 ssi serial clock phase this bit is only applicable to the freescale spi format. the sph control bit selects the clock edge that captures data and allows it to change state. it has the most impact on the first bit transmitted by either allowing or not allowing a clock transition before the first data capture edge. when the sph bit is 0, data is captured on the first clock edge transition. if sph is 1, data is captured on the second clock edge transition. 0 r/w sph 7 ssi serial clock polarity this bit is only applicable to the freescale spi format. when the spo bit is 0, it produces a steady state low value on the ssiclk pin. if spo is 1, a steady state high value is placed on the ssiclk pin when data is not being transferred. 0 r/w spo 6 337 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field ssi frame format select the frf values are defined as follows: frame format frf v alue freescale spi frame format 00 t exas intruments synchronous serial frame format 01 microwire frame format 10 reserved 1 1 0 r/w frf 5:4 ssi data size select the dss values are defined as follows: data size dss v alue reserved 0000-0010 4-bit data 001 1 5-bit data 0100 6-bit data 0101 7-bit data 01 10 8-bit data 01 1 1 9-bit data 1000 10-bit data 1001 1 1-bit data 1010 12-bit data 101 1 13-bit data 1 100 14-bit data 1 101 15-bit data 1 1 10 16-bit data 1 1 1 1 0 r/w dss 3:0 june 14, 2007 338 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 2: ssi control 1 (ssicr1), offset 0x004 ssicr1 is control register 1 and contains bit fields that control various functions within the ssi module. master and slave mode functionality is controlled by this register . ssi control 1 (ssicr1) ssi0 base: 0x4000.8000 of fset 0x004 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 lbm sse ms sod reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 ssi slave mode output disable this bit is relevant only in the slave mode ( ms =1). in multiple-slave systems, it is possible for the ssi master to broadcast a message to all slaves in the system while ensuring that only one slave drives data onto the serial output line. in such systems, the txd lines from multiple slaves could be tied together . t o operate in such a system, the sod bit can be configured so that the ssi slave does not drive the ssitx pin. 0: ssi can drive ssitx output in slave output mode. 1: ssi must not drive the ssitx output in slave mode. 0 r/w sod 3 ssi master/slave select this bit selects master or slave mode and can be modified only when ssi is disabled ( sse =0). 0: device configured as a master . 1: device configured as a slave. 0 r/w ms 2 ssi synchronous serial port enable setting this bit enables ssi operation. 0: ssi operation disabled. 1: ssi operation enabled. note: this bit must be set to 0 before any control registers are reprogrammed. 0 r/w sse 1 ssi loopback mode setting this bit enables loopback t est mode. 0: normal serial port operation enabled. 1: output of the transmit serial shift register is connected internally to the input of the receive serial shift register . 0 r/w lbm 0 339 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: ssi data (ssidr), offset 0x008 ssidr is the data register and is 16-bits wide. when ssidr is read, the entry in the receive fifo (pointed to by the current fifo read pointer) is accessed. as data values are removed by the ssi receive logic from the incoming data frame, they are placed into the entry in the receive fifo (pointed to by the current fifo write pointer). when ssidr is written to, the entry in the transmit fifo (pointed to by the write pointer) is written to. data values are removed from the transmit fifo one value at a time by the transmit logic. it is loaded into the transmit serial shifter , then serially shifted out onto the ssitx pin at the programmed bit rate. when a data size of less than 16 bits is selected, the user must right-justify data written to the transmit fifo. the transmit logic ignores the unused bits. received data less than 16 bits is automatically right-justified in the receive buf fer . when the ssi is programmed for microwire frame format, the default size for transmit data is eight bits (the most significant byte is ignored). the receive data size is controlled by the programmer . the transmit fifo and the receive fifo are not cleared even when the sse bit in the ssicr1 register is set to zero. this allows the software to fill the transmit fifo before enabling the ssi. ssi data (ssidr) ssi0 base: 0x4000.8000 of fset 0x008 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 ssi receive/t ransmit data a read operation reads the receive fifo. a write operation writes the transmit fifo. software must right-justify data when the ssi is programmed for a data size that is less than 16 bits. unused bits at the top are ignored by the transmit logic. the receive logic automatically right-justifies the data. 0 r/w da t a 15:0 june 14, 2007 340 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 4: ssi status (ssisr), offset 0x00c ssisr is a status register that contains bits that indicate the fifo fill status and the ssi busy status. ssi status (ssisr) ssi0 base: 0x4000.8000 of fset 0x00c t ype ro, reset 0x0000.0003 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tfe tnf rne rff bsy reserved r0 ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:5 ssi busy bit 0: ssi is idle. 1: ssi is currently transmitting and/or receiving a frame, or the transmit fifo is not empty . 0 ro bsy 4 ssi receive fifo full 0: receive fifo is not full. 1: receive fifo is full. 0 ro rff 3 ssi receive fifo not empty 0: receive fifo is empty . 1: receive fifo is not empty . 0 ro rne 2 ssi t ransmit fifo not full 0: t ransmit fifo is full. 1: t ransmit fifo is not full. 1 ro tnf 1 ssi t ransmit fifo empty 0: t ransmit fifo is not empty . 1: t ransmit fifo is empty . 1 r0 tfe 0 341 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: ssi clock prescale (ssicpsr), offset 0x010 ssicpsr is the clock prescale register and specifies the division factor by which the system clock must be internally divided before further use. the value programmed into this register must be an even number between 2 and 254. the least-significant bit of the programmed number is hard-coded to zero. if an odd number is written to this register , data read back from this register has the least-significant bit as zero. ssi clock prescale (ssicpsr) ssi0 base: 0x4000.8000 of fset 0x010 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cpsdvsr reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi clock prescale divisor this value must be an even number from 2 to 254, depending on the frequency of ssiclk . the lsb always returns 0 on reads. 0 r/w cpsdvsr 7:0 june 14, 2007 342 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 6: ssi interrupt mask (ssiim), offset 0x014 the ssiim register is the interrupt mask set or clear register . it is a read/write register and all bits are cleared to 0 on reset. on a read, this register gives the current value of the mask on the relevant interrupt. a write of 1 to the particular bit sets the mask, enabling the interrupt to be read. a write of 0 clears the corresponding mask. ssi interrupt mask (ssiim) ssi0 base: 0x4000.8000 of fset 0x014 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rorim r tim rxim txim reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 ssi t ransmit fifo interrupt mask 0: tx fifo half-full or less condition interrupt is masked. 1: tx fifo half-full or less condition interrupt is not masked. 0 r/w txim 3 ssi receive fifo interrupt mask 0: rx fifo half-full or more condition interrupt is masked. 1: rx fifo half-full or more condition interrupt is not masked. 0 r/w rxim 2 ssi receive t ime-out interrupt mask 0: rx fifo time-out interrupt is masked. 1: rx fifo time-out interrupt is not masked. 0 r/w r tim 1 ssi receive overrun interrupt mask 0: rx fifo overrun interrupt is masked. 1: rx fifo overrun interrupt is not masked. 0 r/w rorim 0 343 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: ssi raw interrupt status (ssiris), offset 0x018 the ssiris register is the raw interrupt status register . on a read, this register gives the current raw status value of the corresponding interrupt prior to masking. a write has no ef fect. ssi raw interrupt status (ssiris) ssi0 base: 0x4000.8000 of fset 0x018 t ype ro, reset 0x0000.0008 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rorris r tris rxris txris reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 ssi t ransmit fifo raw interrupt status indicates that the transmit fifo is half full or less, when set. 1 ro txris 3 ssi receive fifo raw interrupt status indicates that the receive fifo is half full or more, when set. 0 ro rxris 2 ssi receive t ime-out raw interrupt status indicates that the receive time-out has occurred, when set. 0 ro r tris 1 ssi receive overrun raw interrupt status indicates that the receive fifo has overflowed, when set. 0 ro rorris 0 june 14, 2007 344 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 8: ssi masked interrupt status (ssimis), offset 0x01c the ssimis register is the masked interrupt status register . on a read, this register gives the current masked status value of the corresponding interrupt. a write has no ef fect. ssi masked interrupt status (ssimis) ssi0 base: 0x4000.8000 of fset 0x01c t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rormis r tmis rxmis txmis reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 ssi t ransmit fifo masked interrupt status indicates that the transmit fifo is half full or less, when set. 0 ro txmis 3 ssi receive fifo masked interrupt status indicates that the receive fifo is half full or more, when set. 0 ro rxmis 2 ssi receive t ime-out masked interrupt status indicates that the receive time-out has occurred, when set. 0 ro r tmis 1 ssi receive overrun masked interrupt status indicates that the receive fifo has overflowed, when set. 0 ro rormis 0 345 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 9: ssi interrupt clear (ssiicr), offset 0x020 the ssiicr register is the interrupt clear register . on a write of 1, the corresponding interrupt is cleared. a write of 0 has no ef fect. ssi interrupt clear (ssiicr) ssi0 base: 0x4000.8000 of fset 0x020 t ype w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 roric r tic reserved w1c w1c ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:2 ssi receive t ime-out interrupt clear 0: no ef fect on interrupt. 1: clears interrupt. 0 w1c r tic 1 ssi receive overrun interrupt clear 0: no ef fect on interrupt. 1: clears interrupt. 0 w1c roric 0 june 14, 2007 346 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 10: ssi peripheral identification 4 (ssiperiphid4), offset 0xfd0 the ssiperiphidn registers are hard-coded and the fields within the register determine the reset value. ssi peripheral identification 4 (ssiperiphid4) ssi0 base: 0x4000.8000 of fset 0xfd0 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid4 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi peripheral id register[7:0] can be used by software to identify the presence of this peripheral. 0x00 ro pid4 7:0 347 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1 1: ssi peripheral identification 5 (ssiperiphid5), offset 0xfd4 the ssiperiphidn registers are hard-coded and the fields within the register determine the reset value. ssi peripheral identification 5 (ssiperiphid5) ssi0 base: 0x4000.8000 of fset 0xfd4 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid5 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi peripheral id register[15:8] can be used by software to identify the presence of this peripheral. 0x00 ro pid5 7:0 june 14, 2007 348 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 12: ssi peripheral identification 6 (ssiperiphid6), offset 0xfd8 the ssiperiphidn registers are hard-coded and the fields within the register determine the reset value. ssi peripheral identification 6 (ssiperiphid6) ssi0 base: 0x4000.8000 of fset 0xfd8 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid6 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi peripheral id register[23:16] can be used by software to identify the presence of this peripheral. 0x00 ro pid6 7:0 349 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 13: ssi peripheral identification 7 (ssiperiphid7), offset 0xfdc the ssiperiphidn registers are hard-coded and the fields within the register determine the reset value. ssi peripheral identification 7 (ssiperiphid7) ssi0 base: 0x4000.8000 of fset 0xfdc t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid7 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi peripheral id register[31:24] can be used by software to identify the presence of this peripheral. 0x00 ro pid7 7:0 june 14, 2007 350 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 14: ssi peripheral identification 0 (ssiperiphid0), offset 0xfe0 the ssiperiphidn registers are hard-coded and the fields within the register determine the reset value. ssi peripheral identification 0 (ssiperiphid0) ssi0 base: 0x4000.8000 of fset 0xfe0 t ype ro, reset 0x0000.0022 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi peripheral id register[7:0] can be used by software to identify the presence of this peripheral. 0x22 ro pid0 7:0 351 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 15: ssi peripheral identification 1 (ssiperiphid1), offset 0xfe4 the ssiperiphidn registers are hard-coded and the fields within the register determine the reset value. ssi peripheral identification 1 (ssiperiphid1) ssi0 base: 0x4000.8000 of fset 0xfe4 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi peripheral id register [15:8] can be used by software to identify the presence of this peripheral. 0x00 ro pid1 7:0 june 14, 2007 352 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 16: ssi peripheral identification 2 (ssiperiphid2), offset 0xfe8 the ssiperiphidn registers are hard-coded and the fields within the register determine the reset value. ssi peripheral identification 2 (ssiperiphid2) ssi0 base: 0x4000.8000 of fset 0xfe8 t ype ro, reset 0x0000.0018 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi peripheral id register [23:16] can be used by software to identify the presence of this peripheral. 0x18 ro pid2 7:0 353 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 17: ssi peripheral identification 3 (ssiperiphid3), offset 0xfec the ssiperiphidn registers are hard-coded and the fields within the register determine the reset value. ssi peripheral identification 3 (ssiperiphid3) ssi0 base: 0x4000.8000 of fset 0xfec t ype ro, reset 0x0000.0001 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 pid3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi peripheral id register [31:24] can be used by software to identify the presence of this peripheral. 0x01 ro pid3 7:0 june 14, 2007 354 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 18: ssi primecell identification 0 (ssipcellid0), offset 0xff0 the ssipcellidn registers are hard-coded and the fields within the register determine the reset value. ssi primecell identification 0 (ssipcellid0) ssi0 base: 0x4000.8000 of fset 0xff0 t ype ro, reset 0x0000.000d 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid0 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi primecell id register [7:0] provides software a standard cross-peripheral identification system. 0x0d ro cid0 7:0 355 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 19: ssi primecell identification 1 (ssipcellid1), offset 0xff4 the ssipcellidn registers are hard-coded and the fields within the register determine the reset value. ssi primecell identification 1 (ssipcellid1) ssi0 base: 0x4000.8000 of fset 0xff4 t ype ro, reset 0x0000.00f0 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid1 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi primecell id register [15:8] provides software a standard cross-peripheral identification system. 0xf0 ro cid1 7:0 june 14, 2007 356 luminary micro confidential-advance product information synchronous serial interface (ssi)
register 20: ssi primecell identification 2 (ssipcellid2), offset 0xff8 the ssipcellidn registers are hard-coded and the fields within the register determine the reset value. ssi primecell identification 2 (ssipcellid2) ssi0 base: 0x4000.8000 of fset 0xff8 t ype ro, reset 0x0000.0005 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi primecell id register [23:16] provides software a standard cross-peripheral identification system. 0x05 ro cid2 7:0 357 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 21: ssi primecell identification 3 (ssipcellid3), offset 0xffc the ssipcellidn registers are hard-coded and the fields within the register determine the reset value. ssi primecell identification 3 (ssipcellid3) ssi0 base: 0x4000.8000 of fset 0xffc t ype ro, reset 0x0000.00b1 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 cid3 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 1 1 0 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 ssi primecell id register [31:24] provides software a standard cross-peripheral identification system. 0xb1 ro cid3 7:0 june 14, 2007 358 luminary micro confidential-advance product information synchronous serial interface (ssi)
15 inter-integrated circuit (i 2 c) interface i2c the inter-integrated circuit (i 2 c) bus provides bi-directional data transfer through a two-wire design (a serial data line sda and a serial clock line scl), and interfaces to external i 2 c devices such as serial memory (rams and roms), networking devices, lcds, tone generators, and so on. the i 2 c bus may also be used for system testing and diagnostic purposes in product development and manufacture. the lm3s8938 microcontroller includes two i 2 c modules, providing the ability to interact (both send and receive) with other i 2 c devices on the bus. devices on the i 2 c bus can be designated as either a master or a slave. each stellaris ? i 2 c module supports both sending and receiving data as either a master or a slave, and also supports the simultaneous operation as both a master and a slave. there are a total of four i 2 c modes: master t ransmit, master receive, slave t ransmit, and slave receive. the stellaris ? i 2 c modules can operate at two speeds: standard (100 kbps) and fast (400 kbps). both the i 2 c master and slave can generate interrupts; the i 2 c master generates interrupts when a transmit or receive operation completes (or aborts due to an error) and the i 2 c slave generates interrupts when data has been sent or requested by a master . 15.1 block diagram figure 15-1. i 2 c block diagram 15.2 functional description the each i 2 c module is comprised of both master and slave functions which are implemented as separate peripherals. for proper operation, the sda and scl pins must be connected to bi-directional open-drain pads. a typical i 2 c bus configuration is shown in figure 15-2 on page 360 . see i 2 c on page 515 for i 2 c timing diagrams. 359 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller i 2 c i /o select i 2 c master core interrupt i 2 c slave core i2cscl i2csda i2csda i2cscl i2csda i2cscl i2cmsa i2cmcs i2cmdr i2cmtpr i2cmimr i2cmris i2cmicr i2cmcr i2csoar i2cscsr i2csdr i2csim i2csris i2csmis i2csicr i2cmmis i 2 c control
figure 15-2. i 2 c bus configuration 15.2.1 i 2 c bus functional overview the i 2 c bus uses only two signals: sda and scl, named i2csda and i2cscl on stellaris ? microcontrollers. sda is the bi-directional serial data line and scl is the bi-directional serial clock line. the bus is considered idle when both lines are high. every transaction on the i 2 c bus is nine bits long, consisting of eight data bits and a single acknowledge bit. the number of bytes per transfer (defined as the time between a valid st ar t and st op condition, described in st ar t and st op conditions on page 360 ) is unrestricted, but each byte has to be followed by an acknowledge bit, and data must be transferred msb first. when a receiver cannot receive another complete byte, it can hold the clock line scl low and force the transmitter into a wait state. the data transfer continues when the receiver releases the clock scl. 15.2.1.1 st art and st op conditions the protocol of the i 2 c bus defines two states to begin and end a transaction: st ar t and st op . a high-to-low transition on the sda line while the scl is high is defined as a st ar t condition, and a low-to-high transition on the sda line while scl is high is defined as a st op condition. the bus is considered busy after a st ar t condition and free after a st op condition. see figure 15-3 on page 360 . figure 15-3. st art and st op conditions 15.2.1.2 data format with 7-bit address data transfers follow the format shown in figure 15-4 on page 361 . after the st ar t condition, a slave address is sent. this address is 7-bits long followed by an eighth bit, which is a data direction bit ( r/s bit in the i2cmsa register). a zero indicates a transmit operation (send), and a one indicates a request for data (receive). a data transfer is always terminated by a st op condition generated by the master , however , a master can initiate communications with another device on the bus by generating a repeated st ar t condition and addressing another slave without first generating a st op condition. v arious combinations of receive/send formats are then possible within a single transfer . june 14, 2007 360 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface r pup stellar is tm i2cscl i2csd a r pup 3rd p ar ty de vice with i 2 c interf ace scl sd a i 2 c bus scl sd a 3rd p ar ty de vice with i 2 c interf ace scl sd a s t a r t c o n d i t i o n sd a sc l s t o p c o n d i t i o n sd a sc l
figure 15-4. complete data t ransfer with a 7-bit address the first seven bits of the first byte make up the slave address (see figure 15-5 on page 361 ). the eighth bit determines the direction of the message. a zero in the r/s position of the first byte means that the master will write (send) data to the selected slave, and a one in this position means that the master will receive data from the slave. figure 15-5. r/s bit in first byte 15.2.1.3 data v alidity the data on the sda line must be stable during the high period of the clock, and the data line can only change when scl is low (see figure 15-6 on page 361 ). figure 15-6. data v alidity during bit t ransfer on the i 2 c bus 15.2.1.4 acknowledge all bus transactions have a required acknowledge clock cycle that is generated by the master . during the acknowledge cycle, the transmitter (which can be the master or slave) releases the sda line. t o acknowledge the transaction, the receiver must pull down sda during the acknowledge clock cycle. the data sent out by the receiver during the acknowledge cycle must comply with the data validity requirements described in data v alidity on page 361 . when a slave receiver does not acknowledge the slave address, sda must be left high by the slave so that the master can generate a st op condition and abort the current transfer . if the master device is acting as a receiver during a transfer , it is responsible for acknowledging each transfer made by the slave. since the master controls the number of bytes in the transfer , it signals the end of data to the slave transmitter by not generating an acknowledge on the last data byte. the slave transmitter must then release sda to allow the master to generate the st op or a repeated st ar t condition. 361 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller c h a n g e o f d a t a a l l o w e d d a t a l i n e s t a b l e s d a s c l d a t a s l a v e a d d r e s s a c k l s b m s b a c k r / s l s b m s b s d a s c l 1 2 7 8 9 1 2 7 8 9 r / s l s b s l a v e a d d r e s s msb
15.2.1.5 arbitration a master may start a transfer only if the bus is idle. its possible for two or more masters to generate a st ar t condition within minimum hold time of the st ar t condition. in these situations, an arbitration scheme takes place on the sda line, while scl is high. during arbitration, the first of the competing master devices to place a '1' (high) on sda while another master transmits a '0' (low) will switch of f its data output stage and retire until the bus is idle again. arbitration can take place over several bits. its first stage is a comparison of address bits, and if both masters are trying to address the same device, arbitration continues on to the comparison of data bits. 15.2.2 a vailable speed modes the i 2 c clock rate is determined by the parameters: clk_prd , timer_prd , scl_lp , and scl_hp . where: clk_prd is the system clock period scl_lp is the low phase of scl (fixed at 6) scl_hp is the high phase of scl (fixed at 4) timer_prd is the programmed value in the i 2 c master t imer period (i2cmtpr) register (see page 379 ). the i 2 c clock period is calculated as follows: scl_period = 2*(1 + timer_prd)*(scl_lp + scl_hp)*clk_prd for example: clk_prd = 50 ns timer_prd = 2 scl_lp=6 scl_hp=4 yields a scl frequency of: 1/t = 333 khz t able 15-1 on page 362 gives examples of t imer period, system clock, and speed mode (standard or fast). t able 15-1. examples of i 2 c master t imer period versus speed mode fast mode t imer period standard mode t imer period system clock - - 100 kbps 0x01 4 mhz - - 100 kbps 0x02 6 mhz 312 kbps 0x01 89 kbps 0x06 12.5 mhz 278 kbps 0x02 93 kbps 0x08 16.7 mhz 333 kbps 0x02 100 kbps 0x09 20 mhz 312 kbps 0x03 96.2 kbps 0x0c 25 mhz 330 kbps 0x04 97.1 kbps 0x10 33mhz 400 kbps 0x04 100 kbps 0x13 40mhz june 14, 2007 362 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
fast mode t imer period standard mode t imer period system clock 357 kbps 0x06 100 kbps 0x18 50mhz 15.2.3 interrupts the i 2 c can generate interrupts when the following conditions are observed: master transaction completed master transaction error slave transaction received slave transaction requested there is a separate interrupt signal for the i 2 c master and i 2 c modules. while both modules can generate interrupts for multiple conditions, only a single interrupt signal is sent to the interrupt controller . 15.2.3.1 i 2 c master interrupts the i 2 c master module generates an interrupt when a transaction completes (either transmit or receive), or when an error occurs during a transaction. t o enable the i 2 c master interrupt, software must write a '1' to the i 2 c master interrupt mask (i2cmimr) register . when an interrupt condition is met, software must check the error bit in the i 2 c master control/status (i2cmcs) register to verify that an error didn't occur during the last transaction. an error condition is asserted if the last transaction wasn't acknowledge by the slave or if the master was forced to give up ownership of the bus due to a lost arbitration round with another master . if an error is not detected, the application can proceed with the transfer . the interrupt is cleared by writing a '1' to the i 2 c master interrupt clear (i2cmicr) register . if the application doesn't require the use of interrupts, the raw interrupt status is always visible via the i 2 c master raw interrupt status (i2cmris) register . 15.2.3.2 i 2 c slave interrupts the slave module generates interrupts as it receives requests from an i 2 c master . t o enable the i 2 c slave interrupt, write a '1' to the i 2 c slave interrupt mask (i2csimr) register . software determines whether the module should write (transmit) or read (receive) data from the i 2 c slave data (i2csdr) register , by checking the rreq and treq bits of the i 2 c slave control/status (i2cscsr) register . if the slave module is in receive mode and the first byte of a transfer is received, the fbr bit is set along with the rreq bit. the interrupt is cleared by writing a '1' to the i 2 c slave interrupt clear (i2csicr) register . if the application doesn't require the use of interrupts, the raw interrupt status is always visible via the i 2 c slave raw interrupt status (i2csris) register . 15.2.4 loopback operation the i 2 c modules can be placed into an internal loopback mode for diagnostic or debug work. this is accomplished by setting the lpbk bit in the i 2 c master configuration (i2cmcr) register . in loopback mode, the sda and scl signals from the master and slave modules are tied together . 363 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
15.2.5 command sequence flow charts this section details the steps required to perform the various i 2 c transfer types in both master and slave mode. 15.2.5.1 i 2 c master command sequences the figures that follow show the command sequences available for the i 2 c master . figure 15-7. master single send june 14, 2007 364 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface idle w rite slave address to i 2cmsa w rite data to i 2cmdr read i2cmcs sequence may be omitted in a single master system busbsy bit=0? no w rite --- 0 - 111 to i 2cmcs yes read i2cmcs busy bit=0? error bit=0? yes error service idle yes no no
figure 15-8. master single receive 365 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller idle w rite slave address to i 2cmsa read i2cmcs sequence may be omitted in a single master system busbsy bit=0? no w rite --- 00111 to i 2cmcs yes read i2cmcs busy bit=0? error bit=0? yes error service idle no no read data from i 2cmdr yes
figure 15-9. master burst send june 14, 2007 366 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface idle w rite slave address to i 2cmsa w rite data to i 2cmdr read i2cmcs busbsy bit=0? yes w rite --- 0 - 011 to i 2cmcs no read i2cmcs busy bit=0? yes error bit=0? yes arblst bit=1? w rite data to i 2cmdr w rite --- 0 - 100 to i 2cmcs index=n? no error service idle yes w rite --- 0 - 001 to i 2cmcs w rite --- 0 - 101 to i 2cmcs yes read i2cmcs busy bit=0? error bit=0? yes no idle yes error service no no no no sequence may be omitted in a single master system
figure 15-10. master burst receive 367 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller idle w rite slave address to i 2cmsa read i2cmcs busbsy bit=0? no w rite --- 01011 to i 2cmcs yes read i2cmcs busy bit=0? no error bit=0? yes arblst bit=1? w rite --- 0 - 100 to i 2cmcs no error service yes idle read data from i 2cmdr index=m-1? w rite --- 00101 to i 2cmcs yes idle read data from i 2cmdr error service error bit=0? yes w rite --- 01001 to i 2cmcs read i2cmcs busy bit=0? no yes sequence may be omitted in a single master system no no no
figure 15-1 1. master burst receive after burst send june 14, 2007 368 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface idle master operates in master t ransmit mode st op condition is not generated w rite slave address to i 2cmsa w rite --- 01011 to i 2cmcs master operates in master receive mode idle repeated st ar t condition is generated with changing data direction
figure 15-12. master burst send after burst receive 15.2.5.2 i 2 c slave command sequences figure 15-13 on page 370 presents the command sequence available for the i 2 c slave. 369 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller idle master operates in master receive mode st op condition is not generated w rite slave address to i 2cmsa w rite --- 0 - 011 to i 2cmcs master operates in master t ransmit mode idle repeated st ar t condition is generated with changing data direction
figure 15-13. slave command sequence 15.3 initialization and configuration the following example shows how to configure the i 2 c module to send a single byte as a master . this assumes the system clock is 20 mhz. 1. enable the i 2 c clock by writing a value of 0x0000.1000 to the rcgc1 register in the system control module. 2. enable the clock to the appropriate gpio module via the rcgc2 register in the system control module. 3. in the gpio module, enable the appropriate pins for their alternate function using the gpioafsel register . also, be sure to enable the same pins for open drain operation. 4. initialize the i 2 c master by writing the i2cmcr register with a value of 0x0000.0020. 5. set the desired scl clock speed of 100 kbps by writing the i2cmtpr register with the correct value. the value written to the i2cmtpr register represents the number of system clock periods in one scl clock period. the tpr value is determined by the following equation: june 14, 2007 370 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface idle w rite own slave address to i 2csoar w rite ------- 1 to i 2cscsr read i2cscsr rreq bit=1? read data from i 2csdr yes treq bit=1? no w rite data to i 2csdr yes no fbr is also valid
tpr = (system clock / (2 * (scl_lp + scl_hp) * scl_clk)) - 1; tpr = (20mhz / (2 * (6 + 4) * 100000)) - 1; tpr = 9 w rite the i2cmtpr register with the value of 0x0000.0009. 6. specify the slave address of the master and that the next operation will be a send by writing the i2cmsa register with a value of 0x0000.0076. this sets the slave address to 0x3b. 7. place data (byte) to be sent in the data register by writing the i2cmdr register with the desired data. 8. initiate a single byte send of the data from master to slave by writing the i2cmcs register with a value of 0x0000.0007 (st op , st ar t , run). 9. w ait until the transmission completes by polling the i2cmcs register s busbsy bit until it has been cleared. 15.4 i 2 c register map t able 15-2 on page 371 lists the i 2 c registers. all addresses given are relative to the i 2 c base addresses for the master and slave: i 2 c master 0: 0x4002.0000 i 2 c slave 0: 0x4002.0800 i 2 c master 1: 0x4002.1000 i 2 c slave 1: 0x4001.1800 t able 15-2. inter-integrated circuit (i 2 c) interface register map see page description reset t ype name offset i 2 c master 373 i2c master slave address 0x0000.0000 r/w i2cmsa 0x000 374 i2c master control/status 0x0000.0000 r/w i2cmcs 0x004 378 i2c master data 0x0000.0000 r/w i2cmdr 0x008 379 i2c master t imer period 0x0000.0001 r/w i2cmtpr 0x00c 380 i2c master interrupt mask 0x0000.0000 r/w i2cmimr 0x010 381 i2c master raw interrupt status 0x0000.0000 ro i2cmris 0x014 382 i2c master masked interrupt status 0x0000.0000 ro i2cmmis 0x018 383 i2c master interrupt clear 0x0000.0000 wo i2cmicr 0x01c 384 i2c master configuration 0x0000.0000 r/w i2cmcr 0x020 i 2 c slave 386 i2c slave own address 0x0000.0000 r/w i2csoar 0x000 371 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
see page description reset t ype name offset 387 i2c slave control/status 0x0000.0000 ro i2cscsr 0x004 389 i2c slave data 0x0000.0000 r/w i2csdr 0x008 390 i2c slave interrupt mask 0x0000.0000 r/w i2csimr 0x00c 391 i2c slave raw interrupt status 0x0000.0000 ro i2csris 0x010 392 i2c slave masked interrupt status 0x0000.0000 ro i2csmis 0x014 393 i2c slave interrupt clear 0x0000.0000 wo i2csicr 0x018 15.5 register descriptions (i 2 c master) the remainder of this section lists and describes the i 2 c master registers, in numerical order by address of fset. see also register descriptions (i2c slave) on page 385 . june 14, 2007 372 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
register 1: i 2 c master slave address (i2cmsa), offset 0x000 this register consists of eight bits: seven address bits (a6-a0), and a receive/send bit, which determines if the next operation is a receive (high), or send (low). i2c master slave address (i2cmsa) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x000 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r/s sa reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 i 2 c slave address this field specifies bits a6 through a0 of the slave address. 0 r/w sa 7:1 receive/send the r/s bit specifies if the next operation is a receive (high) or send (low). 0: send 1: receive 0 r/w r/s 0 373 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 2: i 2 c master control/status (i2cmcs), offset 0x004 this register accesses four control bits when written, and accesses seven status bits when read. the status register consists of seven bits, which when read determine the state of the i 2 c bus controller . the control register consists of four bits: the run , start , stop , and ack bits. the start bit causes the generation of the st ar t , or repea ted st ar t condition. the stop bit determines if the cycle stops at the end of the data cycle, or continues on to a burst. t o generate a single send cycle, the i 2 c master slave address (i2cmsa) register is written with the desired address, the r/s bit is set to 0, and the control register is written with ack =x (0 or 1), stop =1, start =1, and run =1 to perform the operation and stop. when the operation is completed (or aborted due an error), the interrupt pin becomes active and the data may be read from the i2cmdr register . when the i 2 c module operates in master receiver mode, the ack bit must be set normally to logic 1. this causes the i 2 c bus controller to send an acknowledge automatically after each byte. this bit must be reset when the i 2 c bus controller requires no further data to be sent from the slave transmitter . read-only status register i2c master control/status (i2cmcs) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x004 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 busy error adrack da t ack arblst idle busbsy reserved r r r r r r r ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:7 this bit specifies the state of the i 2 c bus. if set, the bus is busy; otherwise, the bus is idle. the bit changes based on the st ar t and st op conditions. 0 r busbsy 6 this bit specifies the i 2 c controller state. if set, the controller is idle; otherwise the controller is not idle. 0 r idle 5 this bit specifies the result of bus arbitration. if set, the controller lost arbitration; otherwise, the controller won arbitration. 0 r arblst 4 this bit specifies the result of the last data operation. if set, the transmitted data was not acknowledged; otherwise, the data was acknowledged. 0 r da t ack 3 june 14, 2007 374 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
description reset t ype name bit/field this bit specifies the result of the last address operation. if set, the transmitted address was not acknowledged; otherwise, the address was acknowledged. 0 r adrack 2 this bit specifies the result of the last bus operation. if set, an error occurred on the last operation; otherwise, no error was detected. the error can be from the slave address not being acknowledged, the transmit data not being acknowledged, or because the controller lost arbitration. 0 r error 1 this bit specifies the state of the controller . if set, the controller is busy; otherwise, the controller is idle. when the busy bit is set, the other status bits are not valid. 0 r busy 0 w rite-only control register i2c master control/status (i2cmcs) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x004 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 run st ar t st op ack reserved w w w w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:4 when set, causes received data byte to be acknowledged automatically by the master . see field decoding in t able 15-3 on page 376 . 0 w ack 3 when set, causes the generation of the st op condition. see field decoding in t able 15-3 on page 376 . 0 w st op 2 when set, causes the generation of a st ar t or repeated st ar t condition. see field decoding in t able 15-3 on page 376 . 0 w st ar t 1 when set, allows the master to send or receive data. see field decoding in t able 15-3 on page 376 . 0 w run 0 375 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
t able 15-3. w rite field decoding for i2cmcs[3:0] field (sheet 1 of 3) description i2cmcs[3:0] i2cmsa[0] current state run st art st op ack r/s st ar t condition followed by send (master goes to the master t ransmit state). 1 1 0 x a 0 idle st ar t condition followed by a send and st op condition (master remains in idle state). 1 1 1 x 0 st ar t condition followed by receive operation with negative ack (master goes to the master receive state). 1 1 0 0 1 st ar t condition followed by receive and st op condition (master remains in idle state). 1 1 1 0 1 st ar t condition followed by receive (master goes to the master receive state). 1 1 0 1 1 illegal. 1 1 1 1 1 nop . all other combinations not listed are non-operations. send operation (master remains in master t ransmit state). 1 0 0 x x master t ransmit st op condition (master goes to idle state). 0 0 1 x x send followed by st op condition (master goes to idle state). 1 0 1 x x repeated st ar t condition followed by a send (master remains in master t ransmit state). 1 1 0 x 0 repeated st ar t condition followed by send and st op condition (master goes to idle state). 1 1 1 x 0 repeated st ar t condition followed by a receive operation with a negative ack (master goes to master receive state). 1 1 0 0 1 repeated st ar t condition followed by a send and st op condition (master goes to idle state). 1 1 1 0 1 repeated st ar t condition followed by receive (master goes to master receive state). 1 1 0 1 1 illegal. 1 1 1 1 1 nop . all other combinations not listed are non-operations. june 14, 2007 376 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
description i2cmcs[3:0] i2cmsa[0] current state run st art st op ack r/s receive operation with negative ack (master remains in master receive state). 1 0 0 0 x master receive st op condition (master goes to idle state). b 0 0 1 x x receive followed by st op condition (master goes to idle state). 1 0 1 0 x receive operation (master remains in master receive state). 1 0 0 1 x illegal. 1 0 1 1 x repeated st ar t condition followed by receive operation with a negative ack (master remains in master receive state). 1 1 0 0 1 repeated st ar t condition followed by receive and st op condition (master goes to idle state). 1 1 1 0 1 repeated st ar t condition followed by receive (master remains in master receive state). 1 1 0 1 1 repeated st ar t condition followed by send (master goes to master t ransmit state). 1 1 0 x 0 repeated st ar t condition followed by send and st op condition (master goes to idle state). 1 1 1 x 0 nop . all other combinations not listed are non-operations. a. an x in a table cell indicates the bit can be 0 or 1. b. in master receive mode, a st op condition should be generated only after a data negative acknowledge executed by the master or an address negative acknowledge executed by the slave. 377 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: i 2 c master data (i2cmdr), offset 0x008 this register contains the data to be transmitted when in the master t ransmit state, and the data received when in the master receive state. i2c master data (i2cmdr) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x008 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 data transferred during transaction. 0x00 r/w da t a 7:0 june 14, 2007 378 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
register 4: i 2 c master t imer period (i2cmtpr), offset 0x00c this register specifies the period of the scl clock. i2c master t imer period (i2cmtpr) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x00c t ype r/w , reset 0x0000.0001 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tpr reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 this field specifies the period of the scl clock. scl_prd = 2*(1 + tpr)*(scl_lp + scl_hp)*clk_prd where: scl_prd is the scl line period (i 2 c clock). tpr is the t imer period register value (range of 1 to 255). scl_lp is the scl low period (fixed at 6). scl_hp is the scl high period (fixed at 4). 0x1 r/w tpr 7:0 379 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: i 2 c master interrupt mask (i2cmimr), offset 0x010 this register controls whether a raw interrupt is promoted to a controller interrupt. i2c master interrupt mask (i2cmimr) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x010 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 im reserved r/w ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 this bit controls whether a raw interrupt is promoted to a controller interrupt. if set, the interrupt is not masked and the interrupt is promoted; otherwise, the interrupt is masked. 0 r/w im 0 june 14, 2007 380 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
register 6: i 2 c master raw interrupt status (i2cmris), offset 0x014 this register specifies whether an interrupt is pending. i2c master raw interrupt status (i2cmris) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x014 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ris reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 this bit specifies the raw interrupt state (prior to masking) of the i 2 c master block. if set, an interrupt is pending; otherwise, an interrupt is not pending. 0 ro ris 0 381 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: i 2 c master masked interrupt status (i2cmmis), offset 0x018 this register specifies whether an interrupt was signaled. i2c master masked interrupt status (i2cmmis) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x018 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mis reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 this bit specifies the raw interrupt state (after masking) of the i 2 c master block. if set, an interrupt was signaled; otherwise, an interrupt has not been generated since the bit was last cleared. 0 ro mis 0 june 14, 2007 382 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
register 8: i 2 c master interrupt clear (i2cmicr), offset 0x01c this register clears the raw interrupt. i2c master interrupt clear (i2cmicr) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x01c t ype wo, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ic reserved wo ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 interrupt clear this bit controls the clearing of the raw interrupt. a write of 1 clears the interrupt; otherwise, a write of 0 has no af fect on the interrupt state. a read of this register returns no meaningful data. 0 wo ic 0 383 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 9: i 2 c master configuration (i2cmcr), offset 0x020 this register configures the mode (master or slave) and sets the interface for test mode loopback. i2c master configuration (i2cmcr) i2c master 0 base: 0x4002.0000 i2c master 1 base: 0x4002.1000 of fset 0x020 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 lpbk reserved mfe sfe reserved r/w ro ro ro r/w r/w ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:6 i 2 c slave function enable this bit specifies whether the interface may operate in slave mode. if set, slave mode is enabled; otherwise, slave mode is disabled. 0 r/w sfe 5 i 2 c master function enable this bit specifies whether the interface may operate in master mode. if set, master mode is enabled; otherwise, master mode is disabled and the interface clock is disabled. 0 r/w mfe 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3:1 i 2 c loopback this bit specifies whether the interface is operating normally or in loopback mode. if set, the device is put in a test mode loopback configuration; otherwise, the device operates normally . 0 r/w lpbk 0 june 14, 2007 384 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
15.6 register descriptions (i2c slave) the remainder of this section lists and describes the i 2 c slave registers, in numerical order by address of fset. see also register descriptions (i 2 c master) on page 372 . 385 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 10: i 2 c slave own address (i2csoar), offset 0x000 this register consists of seven address bits that identify the stellaris ? i 2 c device on the i 2 c bus. i2c slave own address (i2csoar) i2c slave 0 base: 0x4002.0800 i2c slave 1 base: 0x4001.1800 of fset 0x000 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 oar reserved r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:7 i 2 c slave own address this field specifies bits a6 through a0 of the slave address. 0 r/w oar 6:0 june 14, 2007 386 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
register 1 1: i 2 c slave control/status (i2cscsr), offset 0x004 this register accesses one control bit when written, and three status bits when read. the read-only status register consists of three bits: the fbr , rreq , and treq bits. the first byte received (fbr) bit is set only after the stellaris ? device detects its own slave address and receives the first data byte from the i 2 c master . the receive request (rreq) bit indicates that the stellaris ? i 2 c device has received a data byte from an i 2 c master . read one data byte from the i 2 c slave data (i2csdr) register to clear the rreq bit. the transmit request (treq) bit indicates that the stellaris ? i 2 c device is addressed as a slave t ransmitter . w rite one data byte into the i 2 c slave data (i2csdr) register to clear the treq bit. the write-only control register consists of one bit: the da bit. the da bit enables and disables the stellaris ? i 2 c slave operation. read-only status register i2c slave control/status (i2cscsr) i2c slave 0 base: 0x4002.0800 i2c slave 1 base: 0x4001.1800 of fset 0x004 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rreq treq fbr reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:3 indicates that the first byte following the slave s own address is received. this bit is only valid when the rreq bit is set, and is automatically cleared when data has been read from the i2csdr register . note: this bit is not used for slave transmit operations. 0 ro fbr 2 this bit specifies the state of the i 2 c slave with regards to outstanding transmit requests. if set, the i 2 c unit has been addressed as a slave transmitter and uses clock stretching to delay the master until data has been written to the i2csdr register . otherwise, there is no outstanding transmit request. 0 ro treq 1 receive request this bit specifies the status of the i 2 c slave with regards to outstanding receive requests. if set, the i 2 c unit has outstanding receive data from the i 2 c master and uses clock stretching to delay the master until the data has been read from the i2csdr register . otherwise, no receive data is outstanding. 0 ro rreq 0 387 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
w rite-only control register i2c slave control/status (i2cscsr) i2c slave 0 base: 0x4002.0800 i2c slave 1 base: 0x4001.1800 of fset 0x004 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da reserved wo ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 device active 1=enables the i 2 c slave operation. 0=disables the i 2 c slave operation. 0 wo da 0 june 14, 2007 388 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
register 12: i 2 c slave data (i2csdr), offset 0x008 this register contains the data to be transmitted when in the slave t ransmit state, and the data received when in the slave receive state. i2c slave data (i2csdr) i2c slave 0 base: 0x4002.0800 i2c slave 1 base: 0x4001.1800 of fset 0x008 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 this field contains the data for transfer during a slave receive or transmit operation. 0x0 r/w da t a 7:0 389 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 13: i 2 c slave interrupt mask (i2csimr), offset 0x00c this register controls whether a raw interrupt is promoted to a controller interrupt. i2c slave interrupt mask (i2csimr) i2c slave 0 base: 0x4002.0800 i2c slave 1 base: 0x4001.1800 of fset 0x00c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 im reserved r/w ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 this bit controls whether a raw interrupt is promoted to a controller interrupt. if set, the interrupt is not masked and the interrupt is promoted; otherwise, the interrupt is masked. 0 r/w im 0 june 14, 2007 390 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
register 14: i 2 c slave raw interrupt status (i2csris), offset 0x010 this register specifies whether an interrupt is pending. i2c slave raw interrupt status (i2csris) i2c slave 0 base: 0x4002.0800 i2c slave 1 base: 0x4001.1800 of fset 0x010 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ris reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 this bit specifies the raw interrupt state (prior to masking) of the i 2 c slave block. if set, an interrupt is pending; otherwise, an interrupt is not pending. 0 ro ris 0 391 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 15: i 2 c slave masked interrupt status (i2csmis), offset 0x014 this register specifies whether an interrupt was signaled. i2c slave masked interrupt status (i2csmis) i2c slave 0 base: 0x4002.0800 i2c slave 1 base: 0x4001.1800 of fset 0x014 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mis reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 this bit specifies the raw interrupt state (after masking) of the i 2 c slave block. if set, an interrupt was signaled; otherwise, an interrupt has not been generated since the bit was last cleared. 0 ro mis 0 june 14, 2007 392 luminary micro confidential-advance product information inter-integrated circuit (i 2 c) interface
register 16: i 2 c slave interrupt clear (i2csicr), offset 0x018 this register clears the raw interrupt. i2c slave interrupt clear (i2csicr) i2c slave 0 base: 0x4002.0800 i2c slave 1 base: 0x4001.1800 of fset 0x018 t ype wo, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ic reserved wo ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:1 this bit controls the clearing of the raw interrupt. a write of 1 clears the interrupt; otherwise a write of 0 has no af fect on the interrupt state. a read of this register returns no meaningful data. 0 wo ic 0 393 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 controller area network (can) module can 16.1 controller area network overview controller area network (can) is a multicast shared serial bus standard for connecting electronic control units (ecus). can was specifically designed to be robust in electromagnetically noisy environments and can utilize a dif ferential balanced line like rs-485 or a more robust twisted-pair wire. originally created for automotive purposes, it is also used in many embedded control applications (such as industrial and medical). bit rates up to 1 mbps are possible at network lengths below 40 meters. decreased bit rates allow longer network distances (for example, 125 kbps at 500 m). 16.2 controller area network features the stellaris ? can module supports the following features: can protocol version 2.0 part a/b. bit rates up to 1 mbps. 32 message objects. each message object has its own identifier mask. maskable interrupt. disable automatic retransmission mode for t ime t riggered can (ttcan) applications. programmable loopback mode for self-test operation. programmable fifo mode. gluelessly attach to an external can phy through the can0tx and can0rx pins. june 14, 2007 394 luminary micro confidential-advance product information controller area network (can) module
16.3 controller area network block diagram figure 16-1. can module block diagram 395 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller canctl cansts canbit canint cantst canbrpe can control canif1crq canif1cmsk canif1msk1 canif1msk2 canif1arb1 canif1arb2 canif1da1 canif1da2 canif1mctl apb interface apb pins can core message ram 32 message objects canif1db1 canif1db2 canif2crq canif2cmsk canif2msk1 canif2msk2 canif2arb1 canif2arb2 canif2da1 canif2da2 canif2mctl canif2db1 canif2db2 can tx/rx
16.4 controller area network functional description the can module conforms to the can protocol version 2.0 (parts a and b). message transfers that include data, remote, error , and overload frames with an 1 1-bit identifier (standard) or a 29-bit identifier (extended) are supported. t ransfer rates can be programmed up to 1 mbps. the can module consists of three major parts: can protocol controller and message handler message memory can register interface the protocol controller transfers and receives the serial data from the can bus and passes the data on to the message handler . the message handler then loads this information into the appropriate message object based on the current filtering and identifiers in the message object memory . the message handler is also responsible for generating interrupts based on events on the can bus. the message object memory is a set of 32 identical memory blocks that hold the current configuration, status, and actual data for each message object. these are accessed via the can message object register interface. the message memory is not directly accessable in the stellaris memory map, so the stellaris ? can controller provides an interface to communicate with the message memory . the can message object register interface provides two register sets for communicating with the message objects. since there is no direct access to the message object memory , these two interfaces must be used to read or write to each message object. the two message object interfaces allow parallel access to the can controller message objects when multiple objects may have new information that needs to be processed. 16.4.1 initialization the software initialization is started by setting the init bit in the can control (canctl) register , with software or by a hardware reset, or by going bus-of f, which occurs when the transmitter's error counter exceeds a count of 255. while init is set, all message transfers to and from the can bus are stopped and the status of the can transmit output is recessive (high). entering the initialization state does not change the configuration of the can controller , the message objects or the error counters. however , some configuration registers are only accessible when in the initialization state. t o initialize the can controller , set the can bit t iming (canbit) register and configure each message object. if a message object is not needed, it is suf ficient to set it as not valid by clearing the msgval bit in the canifnarb2 register . otherwise, the whole message object has to be initialized, as the fields of the message object may not have valid information causing unexpected results. access to the can bit t iming (canbit) register and to the can baud rate prescalar extension (canbrpe) register to configure the bit timing are enabled when both the init and cce bits in the canctl register are set. t o leave the initialization state, the init bit must be cleared. afterwards, the internal bit stream processor (bsp) synchronizes itself to the data transfer on the can bus by waiting for the occurrence of a sequence of 1 1 consecutive recessive bits (bus idle) before it takes part in bus activities and starts message transfers. the initialization of the message objects is independent of being in the initialization state and can be done on the fly , but message objects should all be configured to particular identifiers or set to not valid before the bsp starts the message transfer . t o change the configuration of a message object during normal operation, set the msgval bit in the canifnarb2 register to 0 (not valid). when the configuration is completed, msgval is set to 1 again (valid). june 14, 2007 396 luminary micro confidential-advance product information controller area network (can) module
16.4.2 operation once the can module is initialized and the init bit in the canctl register is reset to 0, the can module synchronizes itself to the can bus and starts the message transfer . as messages are received, they are stored in their appropriate message objects if they pass the message handler's filtering. the whole message (including all arbitration bits, data-length code, and eight data bytes) is stored in the message object. if the identifier mask (the msk bits in the canifnmskn registers) is used, the arbitration bits which are masked to "don't care" may be overwritten in the message object. the cpu may read or write each message any time via the can interface registers ( canifncrq , canifncmsk , canifnmskn , canifnarbn , canifnmctl , canifndan , and canifndbn ). the message handler guarantees data consistency in case of concurrent accesses. the transmission of message objects are under the control of the software that is managing the can hardware. these can be message objects used for one-time data transfers, or permanent message objects used to respond in a more periodic manner . permanent message objects have all arbitration and control set up and only the data bytes are updated. t o start the transmission, the txrqst bit in the cantxrqn register and the newdat bit in the cannwdan register are set. if several transmit messages are assigned to the same message object (when the number of message objects is not suf ficient), the whole message object has to be configured before the transmission of this message is requested. the transmission of any number of message objects may be requested at the same time; they are transmitted according to their internal priority , which is based on the message identifier for the message object. messages may be updated or set to not valid any time, even when their requested transmission is still pending. the old data is discarded when a message is updated before its pending transmission has started. depending on the configuration of the message object, the transmission of a message may be requested autonomously by the reception of a remote frame with a matching identifier . there are two sets of can interface registers ( canif1x and canif2x ) which are used to access the message objects in the message ram. the can controller coordinates transfers to and from the message ram to and from the registers. the function of the two sets are independent and identical and can be used to queue transactions. 16.4.3 t ransmitting message objects if the internal transmit shift register of the can module is ready for loading, and if there is no data transfer between the can interface registers and message ram, the valid message object with the highest priority and which has a pending transmission request is loaded into the transmit shift register by the message handler and the transmission is started. the message object's newdat bit is reset and can be viewed in the cannwdan register . after a successful transmission, and if no new data was written to the message object since the start of the transmission, the txrqst bit in the canifncmsk register is reset. if the txie bit in the canifnmctl register is set, the intpnd bit in the canifnmctl register is set after a successful transmission. if the can module has lost the arbitration or if an error occurred during the transmission, the message is re-transmitted as soon as the can bus is free again. if, meanwhile, the transmission of a message with higher priority has been requested, the messages are transmitted in the order of their priority . 16.4.4 configuring a t ransmit message object t able 16-1 on page 398 specifies the bit settings for a transmit message object. 397 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
t able 16-1. t ransmit message object bit settings canifnmctl canifnarb2 canifnmctl canifncmsk canifnarb2 register txrqst rmten intpnd txie rxie msglst newdat dir eob mask data arb msgv al bit 0 appl 0 appl 0 0 0 1 1 appl appl appl 1 v alue the xtd and id bit fields in the canifnarbn registers are set by an application. they define the identifier and type of the outgoing message. if an 1 1-bit identifier (standard frame) is used, it is programmed to bits [28:18] of canifnarb1 , as bits 17:0 of canifnarbn are not used by the can controller for 1 1-bit identifiers. if the txie bit is set, the intpnd bit is set after a successful transmission of the message object. if the rmten bit is set, a matching received remote frame causes the txrqst bit to be set and the remote frame is autonomously answered by a data frame with the data from the message object. the dlc bit in the canifnmctl register is set by an application. txrqst and rmten may not be set before the data is valid. the can mask registers ( msk bits in canifnmskn , umask bit in canifnmctl register , and mxtd and mdir bits in canifnmsk2 register) may be used ( umask =1) to allow groups of remote frames with similar identifiers to set the txrqst bit. the dir bit should not be masked. 16.4.5 updating a t ransmit message object the cpu may update the data bytes of a t ransmit message object any time via the can interface registers and neither the msgval nor the txrqst bits have to be reset before the update. even if only a part of the data bytes are to be updated, all four bytes of the corresponding canifndan or canifndbn register have to be valid before the content of that register is transferred to the message object. either the cpu has to write all four bytes into the canifndan or canifndbn register or the message object is transferred to the canifndan or canifndbn register before the cpu writes the new data bytes. in order to just update the data in a message object, the wr , newdat , dataa , and datab bits are written to the can ifn command mask (canifnmskn) register , followed by writing the can ifn data registers, and then the number of the message object is written to the can ifn command request (canifncrq) register , to update the data bytes and the txrqst bit at the same time. t o prevent the reset of txrqst at the end of a transmission that may already be in progress while the data is updated, newdat has to be set together with txrqst . when newdat is set together with txrqst , newdat is reset as soon as the new transmission has started. 16.4.6 accepting received message objects when the arbitration and control field ( id + xtd + rmten + dlc ) of an incoming message is completely shifted into the can module, the message handling capability of the module starts scanning the message ram for a matching valid message object. t o scan the message ram for a matching message object, the acceptance filtering unit is loaded with the arbitration bits from the core. then the arbitration and mask fields (including msgval , umask , newdat , and eob ) of message object 1 are loaded into the acceptance filtering unit and compared with the arbitration field from the shift register . this is repeated with each following message object until a matching message object is found or until the end of the message ram is reached. if a match occurs, the scanning is stopped and the message handler proceeds depending on the type of frame received. june 14, 2007 398 luminary micro confidential-advance product information controller area network (can) module
16.4.7 receiving a data frame the message handler stores the message from the can module receive shift register into the respective message object in the message ram. it stores the data bytes, all arbitration bits, and the data length code into the corresponding message object. this is implemented to keep the data bytes connected with the identifier even if arbitration mask registers are used. the canifnmctl.newdat bit is set to indicate that new data has been received. the cpu should reset canifnmctl.newdat when it reads the message object to indicate to the controller that the message has been received and the buf fer is free to receive more messages. if the can controller receives a message and the canifnmctl.newdat bit was already set, the msglst bit is set to indicate that the previous data was lost. if the canifnmctl.rxie bit is set, the canifnmctl.intpnd bit is set, causing the canint interrupt register to point to the message object that just received a message. the canifnmctl.txrqst bit of this message object is reset to prevent the transmission of a remote frame, while the requested data frame has just been received. 16.4.8 receiving a remote frame when a remote frame is received, three dif ferent configurations of the matching message object have to be considered: dir = 1 (direction = transmit), rmten = 1, umask = 1 or 0 at the reception of a matching remote frame, the txrqst bit of this message object is set. the rest of the message object remains unchanged. dir = 1 (direction = transmit), rmten = 0, umask = 0 at the reception of a matching remote frame, the txrqst bit of this message object remains unchanged; the remote frame is ignored. this remote frame is disabled and will not automatically respond or indicate that the remote frame ever happened. dir = 1 (direction = transmit), rmten = 0, umask = 1 at the reception of a matching remote frame, the txrqst bit of this message object is reset. the arbitration and control field ( id + xtd + rmten + dlc ) from the shift register is stored into the message object in the message ram and the newdat bit of this message object is set. the data field of the message object remains unchanged; the remote frame is treated similar to a received data frame. this is useful for a remote data request from another can device for which the stellaris ? controller does not have readily available data the software must fill the data and answer the frame manually . 16.4.9 receive/t ransmit priority the receive/transmit priority for the message objects is controlled by the message number . message object 1 has the highest priority , while message object 32 has the lowest priority . if more than one transmission request is pending, the message objects are transmitted in order based on the message object with the lowest message number . this should not be confused with the message identifier as that priority is enforced by the can bus. this means that if message object 1 and message object 2 both have valid messages that need to be transmitted, message object 1 will always be transmitted first regardless of the message identifier in the message object itself. 16.4.10 configuring a receive message object t able 16-2 on page 400 specifies the bit settings for a transmit message object. 399 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
t able 16-2. receive message object bit settings canifnmctl canifnarb2 canifnmctl canifncmsk canifnarb2 register txrqst rmten intpnd txie rxie msglst newdat dir eob mask data arb msgv al bit 0 0 0 0 appl 0 0 0 1 appl appl appl 1 v alue the can arbitration registers ( id[28:0] and xtd bit) are set by an application. they define the identifier and type of accepted received messages. if an 1 1-bit identifier (standard frame) is used, it is programmed to id[28:18] and id[17:0] are ignored by the can controller . when a data frame with an 1 1-bit identifier is received, the id[17:0] field is set to 0. if the rxie bit is set, the intpnd bit is set when a received data frame is accepted and stored in the message object. when the message handler stores a data frame in the message object, it stores the received data length code and eight data bytes. if the data length code is less than 8, the remaining bytes of the message object are overwritten by nonspecified values. the can mask registers ( msk bits in canifnmskn , umask bit in canifnmctl register , and mxtd and mdir bits in canifnmsk2 register) may be used ( umask =1) to allow groups of data frames with similar identifiers to be accepted. the dir bit should not be masked in typical applications. 16.4.1 1 handling of received message objects the cpu may read a received message any time via the can interface registers because the data consistency is guaranteed by the message handler state machine. t ypically , the cpu first writes 0x007f to the can ifn command mask (canifncmsk) register and then writes the number of the message object to the can ifn command request (canifncrq) register . that combination transfers the whole received message from the message ram into the message buf fer registers ( canifnmskn , canifnarbn , and canifnmctl ). additionally , the newdat and intpnd bits are cleared in the message ram, acknowledging that the message has been read and clearing the pending interrupt being generated by this message object. if the message object uses masks for acceptance filtering, the arbitration bits show which of the matching messages has been received. the actual value of newdat shows whether a new message has been received since the last time this message object was read. the actual value of msglst shows whether more than one message has been received since the last time this message object was read. msglst is not automatically reset. using a remote frame, the cpu may request new data from another can node on the can bus. setting the txrqst bit of a receive object causes the transmission of a remote frame with the receive object's identifier . this remote frame triggers the other can node to start the transmission of the matching data frame. if the matching data frame is received before the remote frame could be transmitted, the txrqst bit is automatically reset. this prevents the possible loss of data when the other device on the can bus has already transmitted the data, slightly earlier than expected. 16.4.12 handling of interrupts if several interrupts are pending, the can interrupt (canint) register points to the pending interrupt with the highest priority , disregarding their chronological order . an interrupt remains pending until the cpu has cleared it. june 14, 2007 400 luminary micro confidential-advance product information controller area network (can) module
the status interrupt has the highest priority . among the message interrupts, the message object's interrupt priority decreases with increasing message number . a message interrupt is cleared by clearing the message object's intpnd bit. the status interrupt is cleared by reading the can status (cansts) register . the interrupt identifier intid in the canint register indicates the cause of the interrupt. when no interrupt is pending, the register holds the value to 0. if the value of canint is dif ferent from 0, then there is an interrupt pending. if the ie bit is set in the canctl register , the interrupt line to the cpu is active. the interrupt line remains active until canint is 0, all interrupt sources have been cleared, (the cause of the interrupt is reset), or until ie is reset, which disables interrupts from the can controller . the value 0x8000 in the canint register indicates that an interrupt is pending because the can module has updated, but not necessarily changed the cansts register (error interrupt or status interrupt). this indicates that there is either a new error interrupt or a new status interrupt. a write access can clear the rxok, txok, and lec flags in the cansts register , however , only a read access to the cansts register will clear the source of the status interrupt. intid points to the pending message interrupt with the highest interrupt priority . the sie bit in the canctl register controls whether a change of the status register may cause an interrupt. the eie bit in the canctl register controls whether any interrupt from the can controller actually generates an interrupt to the microcontroller's interrupt controller . the canint interrupt register is updated even when the ie bit is set to zero. there are two possibilities when handling the source of a message interrupt. the first is to read the intid bit in the canint interrupt register to determine the highest priority interrupt that is pending, and the second is to read the can message interrupt pending (canmsgnint) register to see all of the message objects that have pending interrupts. an interrupt service routine reading the message that is the source of the interrupt may read the message and reset the message object's intpnd at the same time by setting the clrintpnd bit in the can ifn command mask (canifncmsk) register . when the intpnd bit is cleared, the canint register will contain the message number for the next message object with a pending interrupt. 16.4.13 bit t iming configuration error considerations even if minor errors in the configuration of the can bit timing do not result in immediate failure, the performance of a can network can be reduced significantly . in many cases, the can bit synchronization amends a faulty configuration of the can bit timing to such a degree that only occasionally an error frame is generated. in the case of arbitration, however , when two or more can nodes simultaneously try to transmit a frame, a misplaced sample point may cause one of the transmitters to become error passive. the analysis of such sporadic errors requires a detailed knowledge of the can bit synchronization inside a can node and of the can nodes' interaction on the can bus. 16.4.14 bit t ime and bit rate the can system supports bit rates in the range of lower than 1 kbps up to 1000 kbps. each member of the can network has its own clock generator . the timing parameter of the bit time can be configured individually for each can node, creating a common bit rate even though the can nodes' oscillator periods may be dif ferent. because of small variations in frequency caused by changes in temperature or voltage and by deteriorating components, these oscillators are not absolutely stable. as long as the variations 401 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
remain inside a specific oscillator's tolerance range, the can nodes are able to compensate for the dif ferent bit rates by periodically resynchronizing to the bit stream. according to the can specification, the bit time is divided into four segments (see figure 16-2 on page 402 ): the synchronization segment, the propagation t ime segment, the phase buf fer segment 1, and the phase buf fer segment 2. each segment consists of a specific, programmable number of time quanta (see t able 16-3 on page 402 ). the length of the time quantum ( tq ), which is the basic time unit of the bit time, is defined by the can controller's system clock ( fsys ) and the baud rate prescaler ( brp ): tq = brp / fsys the can module's system clock fsys is the frequency of its can module clock ( can_clk ) input. the synchronization segment sync_seg is that part of the bit time where edges of the can bus level are expected to occur; the distance between an edge that occurs outside of sync_seg and the sync_seg is called the phase error of that edge. the propagation t ime segment prop_seg is intended to compensate for the physical delay times within the can network. the phase buf fer segments phase_seg1 and phase_seg2 surround the sample point. the (re-)synchronization jump width (sjw) defines how far a resynchronization may move the sample point inside the limits defined by the phase buf fer segments to compensate for edge phase errors. a given bit rate may be met by dif ferent bit-time configurations, but for the proper function of the can network, the physical delay times and the oscillator's tolerance range have to be considered. figure 16-2. can bit t ime t able 16-3. can protocol ranges a remark range parameter defines the length of the time quantum t q [1 .. 32] brp fixed length, synchronization of bus input to system clock 1 t q sync_seg compensates for the physical delay times [1 .. 8] t q prop_seg may be lengthened temporarily by synchronization [1 .. 8] t q phase_seg1 may be shortened temporarily by synchronization [1 .. 8] t q phase_seg2 june 14, 2007 402 luminary micro confidential-advance product information controller area network (can) module
remark range parameter may not be longer than either phase buf fer segment [1 .. 4] t q sjw a. this table describes the minimum programmable ranges reqired by the can protocol. the bit timing configuration is programmed in two register bytes in the canbit register . the sum of prop_seg and phase_seg1 (as tseg1 ) is combined with phase_seg2 (as tseg2 ) in one byte, and sjw and brp are combined in the other byte. in these bit timing registers, the four components tseg1 , tseg2 , sjw , and brp have to be programmed to a numerical value that is one less than its functional value; so instead of values in the range of [1..n], values in the range of [0..n-1] are programmed. that way , for example, sjw (functional range of [1..4]) is represented by only two bits. therefore, the length of the bit time is (programmed values): [tseg1 + tseg2 + 3] tq or (functional values): [sync_seg + prop_seg + phase_seg1 + phase_seg2] tq the data in the bit timing registers are the configuration input of the can protocol controller . the baud rate prescalar (configured by brp ) defines the length of the time quantum, the basic time unit of the bit time; the bit t iming logic (configured by tseg1 , tseg2 , and sjw ) defines the number of time quanta in the bit time. the processing of the bit time, the calculation of the position of the sample point, and occasional synchronizations are controlled by the can controller and are evaluated once per time quantum. the can controller translates messages to and from frames. it generates and discards the enclosing fixed format bits, inserts and extracts stuf f bits, calculates and checks the crc code, performs the error management, and decides which type of synchronization is to be used. it is evaluated at the sample point and processes the sampled bus input bit. the time after the sample point that is needed to calculate the next bit to be sent (that is, the data bit, crc bit, stuf f bit, error flag, or idle) is called the information processing t ime (ipt). the ipt is application-specific but may not be longer than 2 tq; the can's ipt is 0 tq. its length is the lower limit of the programmed length of phase_seg2 . in case of synchronization, phase_seg2 may be shortened to a value less than ipt , which does not af fect bus timing. 16.4.15 calculating the bit t iming parameters usually , the calculation of the bit timing configuration starts with a desired bit rate or bit time. the resulting bit time (1/bit rate) must be an integer multiple of the system clock period. the bit time may consist of 4 to 25 time quanta. several combinations may lead to the desired bit time, allowing iterations of the following steps. the first part of the bit time to be defined is the prop_seg . its length depends on the delay times measured in the system. a maximum bus length as well as a maximum node delay has to be defined for expandable can bus systems. the resulting time for prop_seg is converted into time quanta (rounded up to the nearest integer multiple of tq ). the sync_seg is 1 tq long (fixed), which leaves (bit time - prop_seg - 1) tq for the two phase buf fer segments. if the number of remaining tq is even, the phase buf fer segments have the same length, that is, phase_seg2 = phase_seg1 , else phase_seg2 = phase_seg1 + 1. 403 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
the minimum nominal length of phase_seg2 has to be regarded as well. phase_seg2 may not be shorter than the can controller's information processing t ime, which is, depending on the actual implementation, in the range of [0..2] tq. the length of the synchronization jump width is set to its maximum value, which is the minimum of 4 and phase_seg1 . the oscillator tolerance range necessary for the resulting configuration is calculated by the formula given below: (1 -df) x fnom <= fosc <= (1+ df) x fnom where: df = maximum tolerance of oscillator frequency fosc = actual oscillator frequency fnom = nominal oscillator frequency maximum frequency tolerance must take into account the following formulas: df <= (phase_seg1,phase_seg2)min/ 2 x (13 x tbit - phase_seg2) dfmax = 2 x df x fnom where: phase_seg1 and phase_seg2 are from t able 16-3 on page 402 tbit = bit t ime dfmax = maximum dif ference between two oscillators if more than one configuration is possible, that configuration allowing the highest oscillator tolerance range should be chosen. can nodes with dif ferent system clocks require dif ferent configurations to come to the same bit rate. the calculation of the propagation time in the can network, based on the nodes with the longest delay times, is done once for the whole network. the can system's oscillator tolerance range is limited by the node with the lowest tolerance range. the calculation may show that bus length or bit rate have to be decreased or that the oscillator frequencies' stability has to be increased in order to find a protocol-compliant configuration of the can bit timing. the resulting configuration is written into the can bit t iming (canbit) register : (phase_seg2-1)&(phase_seg1+prop_seg-1)&(synchronizationjumpwidth-1)&(prescaler-1) 16.4.15.1 example for bit t iming at high baud rate in this example, the frequency of can_clk is 10 mhz, brp is 0, and the bit rate is 1 mbps. tq 100 ns = tcan_clk delay of bus driver 50 ns delay of receiver circuit 30 ns delay of bus line (40m) 220 ns june 14, 2007 404 luminary micro confidential-advance product information controller area network (can) module
tprop 600 ns = 6 tq tsjw 100 ns = 1 tq ttseg1 700 ns = tprop + tsjw ttseg2 200 ns = information processing time + 1 tq tsync-seg 100 ns = 1 tq bit time 1000 ns = tsync-seg + ttseg1 + ttseg2 tolerance for can_clk 0.39 % = min(pb1,pb2)/ 2 (13 x bit time - pb2) = 0.1us/ 2 x (13x 1us - 2us) in the above example, the concatenated bit time parameters are (2-1)3&(7-1)4&(1-1)2&(1-1)6, and canbit is programmed to 0x1600. 16.4.15.2 example for bit t iming at low baud rate in this example, the frequency of can_clk is 2 mhz, brp is 1, and the bit rate is 100 kbps. tq 1 ms = 2 tcan_clk delay of bus driver 200 ns delay of receiver circuit 80 ns delay of bus line (40m) 220 ns tprop 1 ms = 1 tq tsjw 4 ms = 4 tq ttseg1 5 ms = tprop + tsjw ttseg2 4 ms = information processing time + 3 tq tsync-seg 1 ms = 1 tq bit time 10 ms = tsync-seg + ttseg1 + ttseg2 tolerance for can_clk 1.58 % = min(pb1,pb2)/ 2 x (13 x bit time - pb2) = 4us/ 2 x (13 x 10us - 4us) in this example, the concatenated bit time parameters are (4-1)3&(5-1)4&(4-1)2&(2-1)6, and canbit is programmed to 0x34c1. 16.5 controller area network register map t able 16-4 on page 405 lists the registers. all addresses given are relative to the can base address of: can0: 0x4004.0000 all accesses are on word (32-bit) boundaries. t able 16-4. can register map see page description reset t ype name offset 408 can control 0x0000.0001 r/w canctl 0x000 410 can status 0x0000.0000 r/w cansts 0x004 413 can error counter 0x0000.0000 ro canerr 0x008 414 can bit t iming 0x0000.2301 r/w canbit 0x00c 416 can interrupt 0x0000.0000 ro canint 0x010 405 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
see page description reset t ype name offset 417 can t est 0x0000.0000 r/w cantst 0x014 419 can baud rate prescalar extension 0x0000.0000 r/w canbrpe 0x018 420 can if1 command request 0x0000.0001 r/w canif1crq 0x020 421 can if1 command mask 0x0000.0000 r/w canif1cmsk 0x024 424 can if1 mask 1 0x0000.ffff r/w canif1msk1 0x028 425 can if1 mask 2 0x0000.ffff r/w canif1msk2 0x02c 426 can if1 arbitration 1 0x0000.0000 r/w canif1arb1 0x030 427 can if1 arbitration 2 0x0000.0000 r/w canif1arb2 0x034 428 can if1 message control 0x0000.0000 r/w canif1mctl 0x038 430 can if1 data a1 0x0000.0000 r/w canif1da1 0x03c 431 can if1 data a2 0x0000.0000 r/w canif1da2 0x040 432 can if1 data b1 0x0000.0000 r/w canif1db1 0x044 433 can if1 data b2 0x0000.0000 r/w canif1db2 0x048 420 can if2 command request 0x0000.0001 r/w canif2crq 0x080 421 can if2 command mask 0x0000.0000 r/w canif2cmsk 0x084 424 can if2 mask 1 0x0000.ffff r/w canif2msk1 0x088 425 can if2 mask 2 0x0000.ffff r/w canif2msk2 0x08c 426 can if2 arbitration 1 0x0000.0000 r/w canif2arb1 0x090 427 can if2 arbitration 2 0x0000.0000 r/w canif2arb2 0x094 428 can if2 message control 0x0000.0000 r/w canif2mctl 0x098 430 can if2 data a1 0x0000.0000 r/w canif2da1 0x09c 431 can if2 data a2 0x0000.0000 r/w canif2da2 0x0a0 432 can if2 data b1 0x0000.0000 r/w canif2db1 0x0a4 433 can if2 data b2 0x0000.0000 r/w canif2db2 0x0a8 434 can t ransmission request 1 0x0000.0000 ro cantxrq1 0x100 434 can t ransmission request 2 0x0000.0000 ro cantxrq2 0x104 435 can new data 1 0x0000.0000 ro cannwda1 0x120 435 can new data 2 0x0000.0000 ro cannwda2 0x124 436 can message 1 interrupt pending 0x0000.0000 ro canmsg1int 0x140 436 can message 2 interrupt pending 0x0000.0000 ro canmsg2int 0x144 437 can message 1 v alid 0x0000.0000 ro canmsg1v al 0x160 437 can message 2 v alid 0x0000.0000 ro canmsg2v al 0x164 june 14, 2007 406 luminary micro confidential-advance product information controller area network (can) module
16.6 register descriptions the remainder of this section lists and describes the can registers, in numerical order by address of fset. there are two sets of interface registers which are used to access the message objects in the message ram: canif1x and canif2x . the function of the two sets are identical and are used to queue transactions. 407 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1: can control (canctl), offset 0x000 this control register initializes the module and enables test mode and interrupts. the bus-of f recovery sequence (see can specification rev . 2.0) cannot be shortened by setting or resetting init . if the device goes bus-of f, it sets init , stopping all bus activities. once init has been cleared by the cpu, the device then waits for 129 occurrences of bus idle (129 * 1 1 consecutive high bits) before resuming normal operations. at the end of the bus-of f recovery sequence, the error management counters are reset. during the waiting time after init is reset, each time a sequence of 1 1 high bits has been monitored, a bit0error code is written to the cansts status register , enabling the cpu to readily check whether the can bus is stuck at dominant or continuously disturbed and to monitor the proceeding of the bus-of f recovery sequence. can control (canctl) can0 base: 0x4004.0000 of fset 0x000 t ype r/w , reset 0x0000.0001 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 init ie sie eie reserved dar cce t est reserved r/w r/w r/w r/w ro r/w r/w r/w ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:8 t est mode enable 0: normal operation 1: t est mode 0 r/w t est 7 configuration change enable 0: do not allow write access to the canbit register . 1: allow write access to the canbit register if the init bit is 1. 0 r/w cce 6 disable automatic retransmission 0: auto retransmission of disturbed messages is enabled. 1: auto retransmission is disabled. 0 r/w dar 5 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 4 error interrupt enable 0: disabled. no error status interrupt is generated. 1: enabled. a change in the boff or ewarn bits in the cansts register generates an interrupt. 0 r/w eie 3 june 14, 2007 408 luminary micro confidential-advance product information controller area network (can) module
description reset t ype name bit/field status change interrupt enable 0: disabled. no status change interrupt is generated. 1: enabled. an interrupt is generated when a message has successfully been transmitted or received, or a can bus error has been detected. a change in the txok or rxok bits in the cansts register generates an interrupt. 0 r/w sie 2 module interrupt enable 0: interrupt disabled. 1: interrupt enabled. 0 r/w ie 1 initialization 0: normal operation. 1: initialization started. 1 r/w init 0 409 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 2: can status (cansts), offset 0x004 the status register contains information for interrupt servicing such as bus-of f, error count threshold, and error types. the lec field holds the code that indicates the type of the last error to occur on the can bus. this field is cleared to 0 when a message has been transferred (reception or transmission) without error . the unused error code 7 may be written by the cpu to check for updates. an error interrupt is generated by the boff and ewarn bits and a status change interrupt is generated by the rxok , txok , and lec bits, assuming that the corresponding enable bits in the can control (canctl) register are set. a change of the epass bit or a write to the rxok , txok , or lec bits does not generate an interrupt. reading the can status (cansts) register clears the can interrupt (canint) register , if it is pending. can status (cansts) can0 base: 0x4004.0000 of fset 0x004 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 lec txok rxok epass ew arn bof f reserved r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:8 bus-of f status 0: module is not in bus-of f state. 1: module is in bus-of f state. 0 ro bof f 7 w arning status 0: both error counters are below the error warning limit of 96. 1: at least one of the error counters has reached the error warning limit of 96. 0 ro ew arn 6 error passive 0: the can module is in the error active state, that is, the receive or transmit error count is less than or equal to 127. 1: the can module is in the error passive state, that is, the receive or transmit error count is greater than 127. 0 ro epass 5 june 14, 2007 410 luminary micro confidential-advance product information controller area network (can) module
description reset t ype name bit/field received a message successfully 0: since this bit was last reset to 0, no message has been successfully received. 1: since this bit was last reset to 0, a message has been successfully received, independent of the result of the acceptance filtering. this bit is never reset by the can module. 0 r/w rxok 4 t ransmitted a message successfully 0: since this bit was last reset to 0, no message has been successfully transmitted. 1: since this bit was last reset to 0, a message has been successfully transmitted error-free and acknowledged by at least one other node. this bit is never reset by the can module. 0 r/w txok 3 41 1 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field last error code (type of the last error to occur on the can bus) definition v alue no error 000 stuf f error more than 5 equal bits in a sequence have occurred in a part of a received message where this is not allowed. 001 form error a fixed format part of the received frame has the wrong format. 010 ack error the message transmitted was not acknowledged by another node. 01 1 bit 1 error when a message is transmitted, the can controller monitors the data lines to detect any conflicts. when the arbitration field is transmitted, data conflicts are a part of the arbitration protocol. when other frame fields are transmitted, data conflicts are considered errors. a bit 1 error indicates that the device wanted to send a high level (logical 1) but the monitored bus value was low (logical 0). 100 bit 0 error a bit 0 error indicates that the device wanted to send a low level (logical 0) but the monitored bus value was high (logical 1). during bus-of f recovery , this status is set each time a sequence of 1 1 high bits has been monitored. this enables the cpu to monitor the proceeding of the bus-of f recovery sequence without any disturbances to the bus. 101 crc error the crc checksum was incorrect in the received message indicate that the calculated value received did not match the calculated crc of the data. 1 10 unused when the lec bit shows this value, no can bus event was detected since the cpu wrote this value to lec . 1 1 1 0x0 r/w lec 2:0 june 14, 2007 412 luminary micro confidential-advance product information controller area network (can) module
register 3: can error counter (canerr), offset 0x008 this register contains the error counter values, which can be used to analyze the cause of an error . can error counter (canerr) can0 base: 0x4004.0000 of fset 0x008 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 tec rec rp ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 received error passive 0: the receive error counter is below the error passive level (127 or less). 1: the receive error counter has reached the error passive level (128 or greater). 0 ro rp 15 receive error counter state of the receiver error counter (0 to 127). 0x0 ro rec 14:8 t ransmit error counter state of the transmit error counter (0 to 255). 0x0 ro tec 7:0 413 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 4: can bit t iming (canbit), offset 0x00c this register is used to program the bit width and bit quantum. v alues are to be programmed to an 8-mhz reference clock. this register is write-enabled by the cce and init bits in the canctl register . with a can module clock (can_clk) of 8 mhz, the register reset value of 0x230 configures the can for a bit rate of 500 kbps. can bit t iming (canbit) can0 base: 0x4004.0000 of fset 0x00c t ype r/w , reset 0x0000.2301 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 brp sjw tseg1 tseg2 reserved r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w ro t ype 1 0 0 0 0 0 0 0 1 1 0 0 0 1 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:15 t ime segment after sample point 0x00-0x07: the actual interpretation by the hardware of this value is such that one more than the value programmed here is used. so, for example, a reset value of 0x2 defines that there is 3(2+1) bit time quanta defined for phase_seg2 (see figure 16-2 on page 402 ). the bit time quanta is defined by brp . 0x2 r/w tseg2 14:12 t ime segment before sample point 0x00-0x0f: the actual interpretation by the hardware of this value is such that one more than the value programmed here is used. so, for example, the reset value of 0x3 defines that there is 4(3+1) bit time quanta defined for phase_seg1 (see figure 16-2 on page 402 ). the bit time quanta is define by brp . 0x3 r/w tseg1 1 1:8 (re)synchronization jump width 0x00-0x03: the actual interpretation by the hardware of this value is such that one more than the value programmed here is used. during the start of frame (sof), if the can controller detects a phase error (misalignment), it can adjust the length of tseg2 or tseg1 by the value in sjw . so the reset value of 0 adjusts the length by 1 bit time quanta. 0x0 r/w sjw 7:6 june 14, 2007 414 luminary micro confidential-advance product information controller area network (can) module
description reset t ype name bit/field baud rate prescalar 0x00-0x03f: the value by which the oscillator frequency is divided for generating the bit time quanta. the bit time is built up from a multiple of this quantum. the actual interpretation by the hardware of this value is such that one more than the value programmed here is used. brp defines the number of can clock periods that make up 1 bit time quanta, so the reset value is 2 bit time quanta (1+1). the brpre register can be used to further divide the bit time. 0x1 r/w brp 5:0 415 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: can interrupt (canint), offset 0x010 this register indicates the source of the interrupt. if several interrupts are pending, the can interrupt (canint) register points to the pending interrupt with the highest priority , disregarding their chronological order . an interrupt remains pending until the cpu has cleared it. if the intid bit is not 0x0000 (the default) and the ie bit in the canctl register is set, the interrupt is active. the interrupt line remains active until the intid bit is set back to 0x0000 when the cause of all interrupts are reset or until ie is reset. can interrupt (canint) can0 base: 0x4004.0000 of fset 0x010 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 intid ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 interrupt identifier the number in this field indicates the source of the interrupt. definition v alue no interrupt pending 0x0000 number of the message object that caused the interrupt 0x0001-0x0020 unused 0x0021-0x7fff status interrupt 0x8000 unused 0x8001-0xffff 0x0000 ro intid 15:0 june 14, 2007 416 luminary micro confidential-advance product information controller area network (can) module
register 6: can t est (cantst), offset 0x014 this is the test mode register for self-test and external pin access. it is write-enabled by the test bit in the canctl register . dif ferent test functions may be combined but when the tx bit is not equal to 0x0, it disturbs message transmits. can t est (cantst) can0 base: 0x4004.0000 of fset 0x014 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved basic silent lback tx rx reserved ro ro r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:8 receive observation displays the value on the cannrx pin. 0 ro rx 7 t ransmit control overrides control of canntx pin. description v alue can_tx is controlled by the can module (default) 00 sample point signal driven on the can_tx pin 01 can_tx drives a low value 10 can_tx drives a high value 1 1 0x0 r/w tx 6:5 loopback mode 0: disabled. 1: enabled. 0 r/w lback 4 silent mode do not transmit data; monitor the bus. also known as bus monitor mode. 0: disabled. 1: enabled. 0 r/w silent 3 basic mode 0: disabled. 1: use canif1 registers as transmit buf fer , and use canif2 registers as receive buf fer . 0 r/w basic 2 417 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 1:0 june 14, 2007 418 luminary micro confidential-advance product information controller area network (can) module
register 7: can baud rate prescalar extension (canbrpe), offset 0x018 this register is used to further divide the bit time set with the brp bit in the canbit register . it is write-enabled with the cce bit in the canctl register . can baud rate prescalar extension (canbrpe) can0 base: 0x4004.0000 of fset 0x018 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 brpe reserved r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:4 baud rate prescalar extension. 0x00-0x0f: extend the brp bit to values up to 1023. the actual interpretation by the hardware is one more than the value programmed by brpe (msbs) and brp (lsbs) are used. 0x0 r/w brpe 3:0 419 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 8: can if1 command request (canif1crq), offset 0x020 register 9: can if2 command request (canif2crq), offset 0x080 this register is used to start a transfer when its mnum bit field is updated. its busy bit indicates that the information is transferring from the can interface registers to the internal message ram. a message transfer is started as soon as there is a write of the message object number with the mnum bit. with this write operation, the busy bit is automatically set to 1 to indicate that a transfer is in progress. after a wait time of 3 to 6 can_clk periods, the transfer between the interface register and the message ram completes, which then sets the busy bit back to 0. can if1 command request (canif1crq) can0 base: 0x4004.0000 of fset 0x020 t ype r/w , reset 0x0000.0001 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mnum reserved busy r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 busy flag 0: reset when read/write action has finished. 1: set when a write occurs to the message number in this register . 0x0 ro busy 15 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x00 ro reserved 14:6 message number selects one of the 32 message objects in the message ram for data transfer . the message objects are numbered from 1 to 32. description v alue 0 is not a valid message number; it is interpreted as 0x20, or object 32. 0x00 indicates specified message object 1 to 32. 0x01-0x20 not a valid message number; values are shifted and it is interpreted as 0x01-0x1f . 0x21-0x3f 0x01 r/w mnum 5:0 june 14, 2007 420 luminary micro confidential-advance product information controller area network (can) module
register 10: can if1 command mask (canif1cmsk), offset 0x024 register 1 1: can if2 command mask (canif2cmsk), offset 0x084 the command mask registers specify the transfer direction and select which buf fer registers are the source or target of the data transfer . can if1 command mask (canif1cmsk) can0 base: 0x4004.0000 of fset 0x024 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 datab dataa txrqst/newdat clrintpnd control arb mask wrnrd reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:8 w rite, not read 0: read. t ransfer the message object address specified by the can command request (canifncrq) register to the can message buf fer registers ( canifnmsk1 , canifnmsk2 , canifnarb1 , canifnarb2 , canifnctl , canifnda1 , canifnda2 , canifndb1 , and canifndb2 ). 1: w rite. t ransfer data from the message buf fer registers to the message object address specified by the canifncrq register . 0 r/w wrnrd 7 access mask bits when wrnrd =1 (writes): 0: mask bits unchanged. 1: t ransfer idmask + dir + mxtd to message object. when wrnrd =0 (reads): 0: mask bits unchanged. 1: t ransfer idmask + dir + mxtd of the message object into the interface registers. 0x0 r/w mask 6 access arbitration bits when wrnrd =1 (writes): 0: arbitration bits unchanged. 1: t ransfer id + dir + xtd + msgval to message object. when wrnrd =0 (reads): 0: arbitration bits unchanged. 1: t ransfer id + dir + xtd + msgval to message buf fer register . 0x0 r/w arb 5 421 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field access control bits when wrnrd =1 (writes): 0: control bits unchanged. 1: t ransfer control bits to message object. when wrnrd =0 (reads): 0: control bits unchanged. 1: t ransfer control bits to message buf fer register . 0x0 r/w control 4 clear interrupt pending bit note: this bit is not used when in write ( wrnrd =1). 0: intpnd bit in canifnmctl register remains unchanged. 1: clear intpnd bit in the canifnmctl register in the message object. 0x0 r/w clrintpnd 3 when wrnrd =1 (writes): access t ransmission request bit 0: txrqst bit unchanged. 1: set txrqst bit note: if a transmission is requested by programming this txrqst bit, the parallel txrqst in the canifnmctl register is ignored. when wrnrd =0 (reads): access new data bit 0: newdat bit unchanged. 1: clear newdat bit in the message object. note: a read access to a message object can be combined with the reset of the control bits intpdn and newdat . the values of these bits that are transferred to the canifnmctl register always reflect the status before resetting these bits. 0x0 r/w txrqst/newdat 2 access data byte 0 to 3 when wrnrd =1 (writes): 0: data bytes 0-3 are unchanged. 1: t ransfer data bytes 0-3 ( canifnda1 and canifnda2 ) to message object. when wrnrd =0 (reads): 0: data bytes 0-3 are unchanged. 1: t ransfer data bytes 0-3 in message object to canifnda1 and canifnda2 . 0x0 r/w dataa 1 june 14, 2007 422 luminary micro confidential-advance product information controller area network (can) module
description reset t ype name bit/field access data byte 4 to 7 when wrnrd =1 (writes): 0: data bytes 4-7 unchanged. 1: t ransfer data bytes 4-7 ( canifndb1 and canifndb2 ) to message object. when wrnrd =0 (reads): 0: data bytes 4-7 unchanged. 1: t ransfer data bytes 4-7 in message object to canifndb1 and canifndb2 . 0x0 r/w datab 0 423 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 12: can if1 mask 1 (canif1msk1), offset 0x028 register 13: can if2 mask 1 (canif2msk1), offset 0x088 the mask information provided in this register accompanies the data ( canifndan ), arbitration information ( canifnarbn ), and control information ( canifnmctl ) to the message object in the message ram. the mask is used with the id bit in the canifnarbn register for acceptance filtering. additional mask information is contained in the canifnmsk2 register . can if1 mask 1 (canif1msk1) can0 base: 0x4004.0000 of fset 0x028 t ype r/w , reset 0x0000.ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 msk r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 identifier mask 0: the corresponding identifier bit (id) in the message object cannot inhibit the match in acceptance filtering. 1: the corresponding identifier bit (id) is used for acceptance filtering. 0xff r/w msk 15:0 june 14, 2007 424 luminary micro confidential-advance product information controller area network (can) module
register 14: can if1 mask 2 (canif1msk2), offset 0x02c register 15: can if2 mask 2 (canif2msk2), offset 0x08c this register holds extended mask information that accompanies the canifnmsk1 register . can if1 mask 2 (canif1msk2) can0 base: 0x4004.0000 of fset 0x02c t ype r/w , reset 0x0000.ffff 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 msk reserved mdir mxtd r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w ro r/w r/w t ype 1 1 1 1 1 1 1 1 0 0 0 0 0 1 1 1 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 mask extended identifier 0: the extended identifier bit ( xtd in the canifnarb2 register) has no ef fect on the acceptance filtering. 1: the extended identifier bit xtd is used for acceptance filtering. 0x1 r/w mxtd 15 mask message direction 0: the message direction bit ( dir in the canifnarb2 register) has no ef fect for acceptance filtering. 1: the message direction bit dir is used for acceptance filtering. 0x1 r/w mdir 14 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x1 ro reserved 13 identifier mask 0: the corresponding identifier bit (id) in the message object cannot inhibit the match in acceptance filtering. 1: the corresponding identifier bit (id) is used for acceptance filtering. 0xff r/w msk 12:0 425 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 16: can if1 arbitration 1 (canif1arb1), offset 0x030 register 17: can if2 arbitration 1 (canif2arb1), offset 0x090 this register , along with canifnarb2 , holds the identifiers for acceptance filtering. can if1 arbitration 1 (canif1arb1) can0 base: 0x4004.0000 of fset 0x030 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 id r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 message identifier this bit field is used with the id field in the canifnarb2 register to create the message identifier . id[28:0] is the extended frame and id[28:18] is the standard frame. 0x00 r/w id 15:0 june 14, 2007 426 luminary micro confidential-advance product information controller area network (can) module
register 18: can if1 arbitration 2 (canif1arb2), offset 0x034 register 19: can if2 arbitration 2 (canif2arb2), offset 0x094 this register , along with canifnarb1 , holds information for acceptance filtering. can if1 arbitration 2 (canif1arb2) can0 base: 0x4004.0000 of fset 0x034 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 id dir xtd msgv al r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 message v alid 0: the message object is ignored by the message handler . 1: the message object is configured and will be considered by the message handler within the can controller . all unused message objects should have this bit cleared during initialization and before clearing the init bit in the canctl register . the msgval bit must also be cleared before any of the following bits are modified or if the message object is no longer required: the id bit fields in the canifnarbn registers, the xtd and dir bits in the canifnarb2 register , or the dlc bits in the canifnmctl register . 0x0 r/w msgv al 15 extended identifier 0: the 1 1-bit standard identifier will be used for this message object. 1: the 29-bit extended identifier will be used for this message object. 0x0 r/w xtd 14 message direction 0: receive. on txrqst , a remote frame with the identifier of this message object is transmitted. on reception of a data frame with matching identifier , that message is stored in this message object. 1: t ransmit. on txrqst , the respective message object is transmitted as a data frame. on reception of a remote frame with matching identifier , txrqst bit of this message object is set (if rmten =1). 0x0 r/w dir 13 message identifier used with the id bit in the canifnarb1 register to create the message identifier . id[28:0] is the extended frame and id[28:18] is the standard frame. 0x0 r/w id 12:0 427 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 20: can if1 message control (canif1mctl), offset 0x038 register 21: can if2 message control (canif2mctl), offset 0x098 this register holds the control information associated with the message object to be sent to the message ram. can if1 message control (canif1mctl) can0 base: 0x4004.0000 of fset 0x038 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 dlc reserved eob txrqst rmten rxie txie umask intpnd msglst newdat r/w r/w r/w r/w ro ro ro r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 new data 0: no new data has been written into the data portion of this message object by the message handler since the last time this flag was cleared by the cpu. 1: the message handler or the cpu has written new data into the data portion of this message object. 0x0 r/w newdat 15 message lost 0 : no message was lost since the last time this bit was reset by the cpu. 1: the message handler stored a new message into this object when newdat was set; the cpu has lost a message. this bit is only valid for message objects with the dir bit in the canifnarb2 register set to 0 (receive). 0x0 r/w msglst 14 interrupt pending 0: this message object is not the source of an interrupt. 1: this message object is the source of an interrupt. the interrupt identifier in the can interrupt (canint) register will point to this message object if there is not another interrupt source with a higher priority . 0x0 r/w intpnd 13 use acceptance mask 0: mask ignored. 1: use mask ( msk , mxtd , and mdir ) for acceptance filtering. 0x0 r/w umask 12 june 14, 2007 428 luminary micro confidential-advance product information controller area network (can) module
description reset t ype name bit/field t ransmit interrupt enable 0: the intpnd bit in the canifnmctl register is unchanged after a successful transmission of a frame. 1: the intpnd bit in the canifnmctl register is set after a successful transmission of a frame. 0x0 r/w txie 1 1 receive interrupt enable 0: the intpnd bit in the canifnmctl register is unchanged after a successful reception of a frame. 1: the intpnd bit in the canifnmctl register is set after a successful reception of a frame. 0x0 r/w rxie 10 remote enable 0: at the reception of a remote frame, the txrqst bit in the canifnmctl register is left unchanged. 1: at the reception of a remote frame, the txrqst bit in the canifnmctl register is set. 0x0 r/w rmten 9 t ransmit request 0: this message object is not waiting for transmission. 1: the transmission of this message object is requested and is not yet done. 0x0 r/w txrqst 8 end of buf fer 0: message object belongs to a fifo buf fer and is not the last message object of that fifo buf fer . 1: single message object or last message object of a fifo buf fer . this bit is used to concatenate two or more message objects (up to 32) to build a fifo buf fer . for a single message object (thus not belonging to a fifo buf fer), this bit must be set to 1. 0x0 r/w eob 7 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 6:4 data length code description v alue specifies the number of bytes in the data frame. 0x0-0x8 defaults to a data frame with 8 bytes. 0x9-0xf the dlc bit in the canifnmctl register of a message object must be defined the same as in all the corresponding objects with the same identifier at other nodes. when the message handler stores a data frame, it writes dlc to the value given by the received message. 0x0 r/w dlc 3:0 429 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 22: can if1 data a1 (canif1da1), offset 0x03c register 23: can if2 data a1 (canif2da1), offset 0x09c this register (along with canifnda2 , canifndb1 , and canifndb2 ) contains the data to be sent or that has been received. in a can data frame, data byte 0 is the first byte to be transmitted or received and data byte 7 is the last byte to be transmitted or received. in can's serial bit stream, the msb of each byte is transmitted first. can if1 data a1 (canif1da1) can0 base: 0x4004.0000 of fset 0x03c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 data r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 data bytes 1 and 0 0x00 r/w data 15:0 june 14, 2007 430 luminary micro confidential-advance product information controller area network (can) module
register 24: can if1 data a2 (canif1da2), offset 0x040 register 25: can if2 data a2 (canif2da2), offset 0x0a0 this register (along with canifnda1 , canifndb1 , and canifndb2 ) contains the data to be sent or that has been received. in a can data frame, data byte 0 is the first byte to be transmitted or received and data byte 7 is the last byte to be transmitted or received. in can's serial bit stream, the msb of each byte is transmitted first. can if1 data a2 (canif1da2) can0 base: 0x4004.0000 of fset 0x040 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 data r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 data bytes 3 and 2 0x00 r/w data 15:0 431 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 26: can if1 data b1 (canif1db1), offset 0x044 register 27: can if2 data b1 (canif2db1), offset 0x0a4 this register (along with canifnda1 , canifnda2 , and canifndb2 ) contains the data to be sent or that has been received. in a can data frame, data byte 0 is the first byte to be transmitted or received and data byte 7 is the last byte to be transmitted or received. in can's serial bit stream, the msb of each byte is transmitted first. can if1 data b1 (canif1db1) can0 base: 0x4004.0000 of fset 0x044 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 data r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 data bytes 5 and 4 0x00 r/w data 15:0 june 14, 2007 432 luminary micro confidential-advance product information controller area network (can) module
register 28: can if1 data b2 (canif1db2), offset 0x048 register 29: can if2 data b2 (canif2db2), offset 0x0a8 this register (along with canif1da1 , canif1da2 , and canif1db1 ) contains the data to be sent or that has been received. in a can data frame, data byte 0 is the first byte to be transmitted or received and data byte 7 is the last byte to be transmitted or received. in can's serial bit stream, the msb of each byte is transmitted first. can if1 data b2 (canif1db2) can0 base: 0x4004.0000 of fset 0x048 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 data r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 data bytes 7 and 6 0x00 r/w data 15:0 433 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 30: can t ransmission request 1 (cantxrq1), offset 0x100 register 31: can t ransmission request 2 (cantxrq2), offset 0x104 the cantxrq1 and cantxrq2 registers hold the txrqst bits of the 32 message objects. by reading out these bits, the cpu can check which message object has a transmission request pending. the txrqst bit of a specific message object can be changed by three sources: (1) the cpu via the can ifn message control (canifnmctl) register , (2) the message handler state machine after the reception of a remote frame, or (3) the message handler state machine after a successful transmission. the cantxrq1 register contains the txrqst bit of the first 16 message objects in the message ram; the cantxrq2 register contains the txrqst bit of the second 16 message objects. can t ransmission request 1 (cantxrq1) can0 base: 0x4004.0000 of fset 0x100 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 txrqst ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 t ransmission request bits (of all message objects) 0: the message object is not waiting for transmission. 1: the transmission of the message object is requested and is not yet done. 0x00 ro txrqst 15:0 june 14, 2007 434 luminary micro confidential-advance product information controller area network (can) module
register 32: can new data 1 (cannwda1), offset 0x120 register 33: can new data 2 (cannwda2), offset 0x124 the cannwda1 and cannwda2 registers hold the newdat bits of the 32 message objects. by reading these bits, the cpu can check which message object has its data portion updated. the newdat bit of a specific message object can be changed by three sources: (1) the cpu via the can ifn message control (canifnmctl) register , (2) the message handler state machine after the reception of a data frame, or (3) the message handler state machine after a successful transmission. the cannwda1 register contains the newdat bit of the first 16 message objects in the message ram; the cannwda2 register contains the newdat bit of the second 16 message objects. can new data 1 (cannwda1) can0 base: 0x4004.0000 of fset 0x120 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 newdat ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 new data bits (of all message objects) 0: no new data has been written into the data portion of this message object by the message handler since the last time this flag was cleared by the cpu. 1: the message handler or the cpu has written new data into the data portion of this message object. 0x00 ro newdat 15:0 435 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 34: can message 1 interrupt pending (canmsg1int), offset 0x140 register 35: can message 2 interrupt pending (canmsg2int), offset 0x144 the canmsg1int and canmsg2int registers hold the intpnd bits of the 32 message objects. by reading these bits, the cpu can check which message object has an interrupt pending. the intpnd bit of a specific message object can be changed through two sources: (1) the cpu via the can ifn message control (canifnmctl) register , or (2) the message handler state machine after the reception or transmission of a frame. this field is also encoded in the can interrupt (canint) register . the canmsg1int register contains the intpnd bit of the first 16 message objects in the message ram; the canmsg2int register contains the intpnd bit of the second 16 message objects. can message 1 interrupt pending (canmsg1int) can0 base: 0x4004.0000 of fset 0x140 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 intpnd ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 interrupt pending bits (of all message objects) 0: this message object is not the source of an interrupt. 1: this message object is the source of an interrupt. 0x00 ro intpnd 15:0 june 14, 2007 436 luminary micro confidential-advance product information controller area network (can) module
register 36: can message 1 v alid (canmsg1v al), offset 0x160 register 37: can message 2 v alid (canmsg2v al), offset 0x164 the canmsg1v al and canmsg2v al registers hold the msgval bits of the 32 message objects. by reading these bits, the cpu can check which message object is valid. the message value of a specific message object can be changed with the can ifn message control (canifnmctl) register . the canmsg1v al register contains the msgval bit of the first 16 message objects in the message ram; the canmsg2v al register contains the msgval bit of the second 16 message objects in the message ram can message 1 v alid (canmsg1v al) can0 base: 0x4004.0000 of fset 0x160 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 msgv al ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0000 ro reserved 31:16 message v alid bits (of all message objects) 0: this message object is not configured and is ignored by the message handler . 1: this message object is configured and should be considered by the message handler . 0x00 ro msgv al 15:0 437 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
17 ethernet controller enet the stellaris ? ethernet controller consists of a fully integrated media access controller (mac) and network physical (phy) interface device. the ethernet controller conforms to iee 802.3 specifications and fully supports 10base-t and 100base-tx standards. the ethernet controller module has the following features: conforms to the ieee 802.3-2002 specification C 10base-t/100base-tx ieee-802.3 compliant. requires only a dual 1:1 isolation transformer interface to the line. C 10base-t/100base-tx endec, 100base-tx scrambler/descrambler C full-featured auto-negotiation multiple operational modes C full- and half-duplex 100 mbps C full- and half-duplex 10 mbps C power-saving and power-down modes highly configurable C programmable mac address C led activity selection C promiscuous mode support C crc error-rejection control C user-configurable interrupts physical media manipulation C automatic mdi/mdi-x cross-over correction C register-programmable transmit amplitude C automatic polarity correction and 10base-t signal reception june 14, 2007 438 luminary micro confidential-advance product information ethernet controller
17.1 block diagram figure 17-1. ethernet controller block diagram 17.2 functional description as illustrated in figure 17-2 on page 439 , the ethernet controller is functionally divided into two layers or modules - the media access controller (mac) layer and network physical (phy) layer . these correspond to the osi model layers 2 and 1. the primary interface to the ethernet controller is a simple bus interface to the mac layer . the mac layer provides transmit and receive processing for ethernet frames. the mac layer also provides the interface to the phy module via an internal media independent interface (mii). figure 17-2. ethernet controller 17.2.1 internal mii operation for the mii management interface to function properly , the mdio signal must be connected through a 10k ? pull-up resistor to the +3.3v supply . failure to connect this pull-up resistor will prevent management transactions on this internal mii to function. note that it is possible for data transmission across the mii to still function since the phy layer will auto-negotiate the link parameters by default. 439 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller macisr maciack macimr interrupt control macrcr macnpr receive control mactcr macithr mactrr t ransmit control t ransmit fifo receive fifo maciar0 maciar1 individual address macmdtx macmcr macmdvr macmar macmdrx mii control macdr data access mactsr t imer support txop txon rxip rxin xtlp xtln mdix clock reference t ransmit encoding pulse shaping receive decoding clock recovery auto negotiation carrier sense mr3 mr0 mr1 mr2 mr4 media independent interface management register set mr5 mr18 mr6 mr16 mr17 mr19 mr23 mr24 collision detect system clock interrupt cortex m3 media access controller mac ( layer 2) physical layer entity phy ( layer 1) magnetics rj45 ethernet controller
for the mii management interface to function properly , the internal clock must be divided down from the system clock to a frequency no greater than 2.5 mhz. the macmdv register contains the divider used for scaling down the system clock. see page 458 for more details about the use of this register . 17.2.2 phy configuration/operation the physical layer (phy) in the ethernet controller includes integrated endecs, scrambler/descrambler , dual-speed clock recovery , and full-featured auto-negotiation functions. the transmitter includes an on-chip pulse shaper and a low-power line driver . the receiver has an adaptive equalizer and a baseline restoration circuit required for accurate clock and data recovery . the transceiver interfaces to category-5 unshielded twisted pair (cat-5 utp) cabling for 100base-tx applications, and category-3 unshielded twisted pair (cat-3 utp) for 10base-t applications. the ethernet controller is connected to the line media via dual 1:1 isolation transformers. no external filter is required. 17.2.2.1 clock selection the phy has an on-chip crystal oscillator which can also be driven by an external oscillator . in this mode of operation, a 25-mhz crystal should be connected between the xtlpphy and xtlnphy pins. alternatively , an external 25-mhz clock input can be connected to the xtlp pin. in this mode of operation, a crystal is not required and the xtln pin must be tied to ground. 17.2.2.2 auto-negotation the phy supports the auto-negotiation functions of clause 28 of the ieee 802.3 standard for 10/100 mbps operation over copper wiring. this function can be enabled via register settings. the autonegotiation function defaults to on and bit 12 ( anegen ) in the mr0 register is high after reset. software can disable the auto-negotiation function by writing to the anegen bit. the contents of the mr4 register are sent to the phy s link partner during auto-negotiation via fast-link pulse coding. once auto-negotiation is complete, bits 1 1:10 ( dplx and rate ) in the mr18 register reflect the actual speed and duplex that was chosen. if auto-negotiation fails to establish a link for any reason, bit 12 ( anegf ) in the mr18 register reflects this and auto-negotiation restarts from the beginning. w riting a 1 to bit 9 ( raneg ) in the mr0 register also causes auto-negotiation to restart. 17.2.2.3 polarity correction the phy is capable of either automatic or manual polarity reversal for 10base-t and auto-negotiation functions. bits 4 and 5 ( rvspol and apol ) in the mr16 register control this feature. the default is automatic mode, where apol is low and rvspol indicates if the detection circuitry has inverted the input signal. t o enter manual mode, apol should be set high and rvspol then controls the signal polarity . 17.2.2.4 mdi/mdi-x configuration the phy supports the automatic mdi/mdi-x configuration as defined in ieee 802.3 2002. this eliminates the need for cross-over cables when connecting to another devices, such as a hub. the algorithm is controlled via settings in the mr24 register . refer to page 481 for additional details about these settings. 17.2.2.5 led indicators the phy supports two led signals that can be used to indicate various states of operation of the ethernet controller . these signals are mapped to the led0 and led1 pins. by default, these pins are configured as gpio signals (pf3 and pf2). for the phy layer to drive these signals, they must be reconfigured to their hardware function. refer to the gipo chapter for additional details. the june 14, 2007 440 luminary micro confidential-advance product information ethernet controller
function of these pins is programmable via the phy layer mr23 register . refer to page 480 for additonal details on how to program these led functions. 17.2.3 mac configuration/operation 17.2.3.1 ethernet frame format ethernet data is carried by ethernet frames. the basic frame format is shown in figure 17-3 on page 441 . figure 17-3. ethernet frame the seven fields of the frame are transmitted from left to right. the bits within the frame are transmitted from least to most significant bit. preamble the preamble field is used by the physical layer signaling circuitry to synchronize with the received frame s timing. the preamble is 7 octets long. start frame delimiter (sfd) the sfd field follows the preamble pattern and indicates the start of the frame. its value is 1010.101 1. destination address (da) this field specifies destination addresses for which the frame is intended. the lsb of the da determines whether the address is an individual (0), or group/multicast (1) address. source address (sa) the source address field identifies the station from which the frame was initiated. length/t ype field the meaning of this field depends on its numeric value. the first of two octets is most significant. this field can be interpreted as length or type code. the maximum length of the data field is 1500 octets. if the value of the length/t ype field is less than or equal to 1500 decimal, it indicates the number of mac client data octets. if the value of this field is greater than or equal to 1536 decimal, then it is type interpretation. the meaning of the length/t ype field when the value is between 1500 and 1536 decimal is unspecified by the standard. the mac module assumes type interpretation if the value of the length/t ype field is greater than 1500 decimal. data the data field is a sequence of 0 to 1500 octets. full data transparency is provided so any values can appear in this field. a minimum frame size is required to properly meet the ieee standard. if necessary , the data field is extended by appending extra bits (a pad). the pad field can have a size of 0 to 46 octets. the sum of the data and pad lengths must be a minimum of 46 octets. the mac module automatically inserts pads if required, though it can be disabled by a register 441 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller preamble sfd destination address source address length/ t ype fcs data 7 bytes 6 bytes 6 bytes 2 bytes 1 byte 4 bytes 46 - 1500 bytes
write. for the mac module core, data sent/received can be larger than 1500 bytes, and no frame t oo long error is reported. instead, a fifo overrun error is reported when the frame received is too large to fit into the ethernet controller s ram. frame check sequence (fcs) the frame check sequence carries the crc (cyclic redundancy check value). the value of this field is computed over destination address, source address, length/type, data, and pad fields using the crc-32 algorithm. the mac module computes the fcs value one nibble at a time. for transmitted frames, this field is automatically inserted by the mac layer , unless disabled by the crc bit in the mactctl register . for received frames, this field is automatically checked. if the fcs does not pass, the frame will not be placed in the rx fifo, unless the fcs check is disabled by the badcrc bit in the macrctl register . 17.2.3.2 mac layer fifos for ethernet frame transmission, a 2k byte tx fifo is provided that can be used to store a single frame. while the ieee 802.3 specification limits the size of an ethernet frame's payload section to 1500 bytes, the ethernet controller places no such limit. the full buf fer can be used, for a paylload of up to 2032 bytes. for ethernet frame reception, a 2k byte rx fifo is provided that can be used to store multiple frames, up to a maximum of 31 frames. if a frame is received and there is insuf ficient space in the rx fifo, an overflow error will be indicated. for details regarding the tx and rx fifo layout, refer to t able 17-1 on page 442 . please note the following dif ference between tx and rx fifo layout. for the tx fifo, the data length field in the first fifo word refers to the ethernet frame data payload, as shown in the 5th to nth fifo positions. for the rx fifo, the frame lenth field is the total length of the receieved ethernet frame, including the fcs and frame length bytes. also note that if fcs generation is disabled with the crc bit in the mactctl register , the last word in the fifo must be the fcs bytes for the frame that has been written to the fifo. also note that if the length of the data payload section is not a multiple of 4, the fcs field will overlap words in the fifo. however , for the rx fifo, the beginning of the next frame will always be on a word boundary . t able 17-1. tx & rx fifo organization rx fifo (read) tx fifo (w rite) w ord bit fields fifo w ord read/w rite sequence frame length lsb data length lsb 7:0 1st frame length msb data length msb 15:8 da oct 1 23:16 da oct 2 31:24 da oct 3 7:0 2nd da oct 4 15:8 da oct 5 23:16 da oct 6 31:24 sa oct 1 7:0 3rd sa oct 2 15:8 sa oct 3 23:16 sa oct 4 31:24 june 14, 2007 442 luminary micro confidential-advance product information ethernet controller
rx fifo (read) tx fifo (w rite) w ord bit fields fifo w ord read/w rite sequence sa oct 5 7:0 4th sa oct 6 15:8 len/t ype msb 23:16 len/t ype lsb 31:24 data oct n 7:0 5th to nth data oct n+1 15:8 data oct n+2 23:16 data oct n+3 31:24 fcs 1 fcs 1 (if crc generation is disabled in mactctl) 7:0 last fcs 2 fcs 2 (if crc generation is disabled in mactctl) 15:8 fcs 3 fcs 3 (if crc generation is disabled in mactctl) 23:16 fcs 4 fcs 4 (if crc generation is disabled in mactctl) 31:24 17.2.3.3 ethernet t ransmission options the ethernet controller can automatically generate and insert the frame check sequence (fcs) at the end of the transmit frame. this is controlled by the crc bit in the mactctl register . for test purposes, in order to generate a frame with an invalid crc, this feature can be disabled. the ieee 802.3 specification requires that the ethernet frame payload section be a minimum of 46 bytes. the ethernet controller can be configured to automatically pad the data section if the payload data section loaded into the fifo is less than the minimum 46 bytes. this feature is controlled by the p aden bit in the mactctl register . at the mac layer , the transmitter can be configured for both full-duplex and half-duplex operation by using the duplex bit in the mactctl register . 17.2.3.4 ethernet reception options using the badcrc bit in the macrctl register , the ethernet controller can be configured to reject incoming ethernet frames with an invalid frame check sequence field. the ethernet receiver can also be configured for promiscuous and multicast modes using the prms and amul fields in the macrctl register . if these modes are not enabled, only ethernet frames with a broadcast address, or frames matching the mac address programmed into the macia0 and macia1 register will be placed into the rx fifo. 17.2.4 interrupts the ethernet controller can generate an interrupt for one or more of the following conditions. a frame has been received into an empty rx fifo. a frame transmission error has occurred a frame has been transmitted successfully . a frame has been received with no room in the rx fifo (overrun). 443 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
a frame has been received with one or more error conditions (e.g. fcs failed). an mii management transaction between the mac and phy layers has completed. one or more of the following phy layer conditions occurs. C auto negotiate complete C remote fault C link status change C link partner acknowledge C parallel detect fault C page received C receive error C jabber event detected 17.3 initialization and configuration t o use the ethernet controller , the peripheral must be enabled by setting the eth bits in the rcgc2 register . the following steps can then be used to configure the ethernet controller for basic operation. 1. program the macdiv register to obtain a 2.5 mhz clock (or less) on the internal mii. assuming a 20 mhz system clock, the macdiv value would be 4. 2. program the macia0 and macia1 register for address filtering. 3. program the mactctl register for auto crc generation, padding, and full duplex operation using a value of 0x16. 4. program the macrctl register to reject frames with bad fcs using a value of 0x08. 5. enable both the t ransmitter and receive by setting the lsb in both the mactctl and macrctl register . 6. t o transmit a frame, write the frame into the tx fifo using the macda t a register . then set the newtx bit in the mactr register to initiate the transmit process. when the newtx bit has been cleared, the tx fifo will be available for the next transmit frame. 7. t o receive a frame, wait for the npr field in the macnp register to be non-zero. then begin reading the frame from the rx fifo by using the macda t a register . when the frame (including the fcs field) has been read, the npr field should decrement by one. when there are no more frames in the rx fifo, the npr field will read 0. 17.4 ethernet register map t able 17-2 on page 445 lists the ethernet mac registers. all addresses given are relative to the ethernet mac base address of 0x4004.8000. the ieee 802.3 standard specifies a register set for controlling and gathering status from the phy . the registers are collectively known as the mii management registers and are detailed in section june 14, 2007 444 luminary micro confidential-advance product information ethernet controller
22.2.4 of the ieee 802.3 specification. t able 17-2 on page 445 lists the mii management registers. all addresses given are absolute and are written directly to the regadr field of the macmctl register . the format of registers 0 to 15 are defined by the ieee specification and are common to all phy implementations. the only variance allowed is for features that may or may not be supported by a specific phy . registers 16 to 31 are vendor-specific registers, used to support features that are specific to a vendors phy implementation. v endor-specific registers not listed are reserved. t able 17-2. ethernet register map see page description reset t ype name offset ethernet mac 447 ethernet mac raw interrupt status 0x0000.0000 ro macris 0x000 449 ethernet mac interrupt acknowledge 0x0000.0000 w1c maciack 0x000 450 ethernet mac interrupt mask 0x0000.007f r/w macim 0x004 451 ethernet mac receive control 0x0000.0008 r/w macrctl 0x008 452 ethernet mac t ransmit control 0x0000.0000 r/w mactctl 0x00c 453 ethernet mac data 0x0000.0000 r/w macda t a 0x010 454 ethernet mac individual address 0 0x0000.0000 r/w macia0 0x014 455 ethernet mac individual address 1 0x0000.0000 r/w macia1 0x018 456 ethernet mac threshold 0x0000.003f r/w macthr 0x01c 457 ethernet mac management control 0x0000.0000 r/w macmctl 0x020 458 ethernet mac management divider 0x0000.0080 r/w macmdv 0x024 459 ethernet mac management address 0x0000.0000 ro macmadd 0x028 460 ethernet mac management t ransmit data 0x0000.0000 r/w macmtxd 0x02c 461 ethernet mac management receive data 0x0000.0000 r/w macmrxd 0x030 462 ethernet mac number of packets 0x0000.0000 ro macnp 0x034 463 ethernet mac t ransmission request 0x0000.0000 r/w mactr 0x038 mii management 464 ethernet phy management register 0 C control 0x3100 r/w mr0 0x00 466 ethernet phy management register 1 C status 0x7849 ro mr1 0x01 468 ethernet phy management register 2 C phy identifier 1 0x000e ro mr2 0x02 469 ethernet phy management register 3 C phy identifier 2 0x7237 ro mr3 0x03 470 ethernet phy management register 4 C auto-negotiation advertisement 0x01e1 r/w mr4 0x04 472 ethernet phy management register 5 C auto-negotiation link partner base page ability 0x0000 ro mr5 0x05 473 ethernet phy management register 6 C auto-negotiation expansion 0x0000 ro mr6 0x06 445 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
see page description reset t ype name offset 474 ethernet phy management register 16 C v endor-specific 0x0140 r/w mr16 0x10 476 ethernet phy management register 17 C interrupt control/status 0x0000 r/w mr17 0x1 1 478 ethernet phy management register 18 C diagnostic 0x0000 ro mr18 0x12 479 ethernet phy management register 19 C t ransceiver control 0x4000 r/w mr19 0x13 480 ethernet phy management register 23 C led configuration 0x0010 r/w mr23 0x17 481 ethernet phy management register 24 Cmdi/mdix control 0x00c0 r/w mr24 0x18 17.5 ethernet mac register descriptions the remainder of this section lists and describes the ethernet mac registers, in numerical order by address of fset. june 14, 2007 446 luminary micro confidential-advance product information ethernet controller
register 1: ethernet mac raw interrupt status (macris), offset 0x000 the macris register is the interrupt status register . on a read, this register gives the current status value of the corresponding interrupt prior to masking. ethernet mac raw interrupt status (macris) base 0x4004.8000 of fset 0x000 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rxint txer txemp fov rxer mdint phyint reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:7 when set, indicates that an enabled interrupt in the phy layer has occured. mr17 in the phy must be read to determine the specific phy event that triggered this interrupt. 0x0 ro phyint 6 when set, indicates that a transaction (read or write) on the mii interface has completed successfully . 0x0 ro mdint 5 this bit indicates that an error was encountered on the receiver . the possible errors that can cause this interrupt bit to be set are: a receive error occurs during the reception of a frame (100 mb/s only). the frame is not an integer number of bytes (dribble bits) due to an alignment error . the crc of the frame does not pass the fcs check. the length/type field is inconsistent with the frame data size when interpreted as a length field. 0x0 ro rxer 4 when set, indicates that an overrun was encountered on the receive fifo. 0x0 ro fov 3 when set, indicates that the packet was transmitted and that the tx fifo is empty . 0x0 ro txemp 2 when set, indicates that an error was encountered on the transmitter . the possible errors that can cause this interrupt bit to be set are: the data length field stored in the tx fifo exceeds 2032. the frame is not sent when this error occurs. the retransmission attempts during the backof f process have exceeded the maximum limit of 16. 0x0 ro txer 1 447 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field when set, indicates that at least one packet has been received and is stored in the receiver fifo. 0x0 ro rxint 0 june 14, 2007 448 luminary micro confidential-advance product information ethernet controller
register 2: ethernet mac interrupt acknowledge (maciack), offset 0x000 a write of a 1 to any bit position of this register clears the corresponding interrupt bit in the ethernet mac raw interrupt status (macris) register . ethernet mac interrupt acknowledge (maciack) base 0x4004.8000 of fset 0x000 t ype w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rxint txer txemp fov rxer mdint reserved w1c w1c w1c w1c w1c w1c ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:6 a write of a 1 to the phyint bit clears the phyint interrupt read from the macris register . 0x0 w1c phyint 6 a write of a 1 to the mdint bit clears the mdint interrupt read from the macris register . 0x0 w1c mdint 5 a write of a 1 to the rxer bit clears the rxer interrupt read from the macris register . 0x0 w1c rxer 4 a write of a 1 to the fov bit clears the fov interrupt read from the macris register . 0x0 w1c fov 3 a write of a 1 to the txemp bit clears the txemp interrupt read from the macris register . 0x0 w1c txemp 2 a write of a 1 to the txer bit clears the txer interrupt read from the macris register and resets the tx fifo write pointer . 0x0 w1c txer 1 a write of a 1 to the rxint bit clears the rxint interrupt read from the macris register . 0x0 w1c rxint 0 449 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: ethernet mac interrupt mask (macim), offset 0x004 this register allows software to enable/disable ethernet mac interrupts. w riting a 0 disables the interrupt, while writing a 1 enables it. ethernet mac interrupt mask (macim) base 0x4004.8000 of fset 0x004 t ype r/w , reset 0x0000.007f 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rxintm txerm txempm fovm rxerm mdintm phyintm reserved r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:7 the phyintm bit masks the phyint bit in the macris register from being asserted. 1 r/w phyintm 6 the mdintm bit masks the mdint bit in the macris register from being asserted. 1 r/w mdintm 5 the rxerm bit masks the rxer bit in the macris register from being asserted. 1 r/w rxerm 4 the fovm bit masks the fov bit in the macris register from being asserted. 1 r/w fovm 3 the txempm bit masks the txemp bit in the macris register from being asserted. 1 r/w txempm 2 the txerm bit masks the txer bit in the macris register from being asserted. 1 r/w txerm 1 the rxintm bit masks the rxint bit in the macris register from being asserted. 1 r/w rxintm 0 june 14, 2007 450 luminary micro confidential-advance product information ethernet controller
register 4: ethernet mac receive control (macrctl), offset 0x008 this register enables software to configure the receive module and control the types of frames that are received from the physical medium. it is important to note that when the receive module is enabled, all valid frames with a broadcast address of ff-ff-ff-ff-ff-ff in the destination address field will be received and stored in the rx fifo, even if the amul bit is not set. ethernet mac receive control (macrctl) base 0x4004.8000 of fset 0x008 t ype r/w , reset 0x0000.0008 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rxen amul prms badcrc rstfifo reserved r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:5 when set, clears the receive fifo. this should be done when software initialization is performed. it is recommended that the receiver be disabled ( rxen = 0), and then the reset initiated ( rstfifo = 1). this sequence will flush and reset the rx fifo. 0x0 r/w rstfifo 4 the badcrc bit enables the rejection of frames with an incorrectly calculated crc. 0x1 r/w badcrc 3 the prms bit enables promiscuous mode, which accepts all valid frames, regardless of the destination address. 0x0 r/w prms 2 the amul bit enables the reception of multicast frames from the physical medium. 0x0 r/w amul 1 the rxen bit enables the ethernet receiver . when this bit is low , the receiver is disabled and all frames on the physical medium are ignored. 0x0 r/w rxen 0 451 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: ethernet mac t ransmit control (mactctl), offset 0x00c this register enables software to configure the transmit module, and control frames are placed onto the physical medium. ethernet mac t ransmit control (mactctl) base 0x4004.8000 of fset 0x00c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 txen p aden crc reserved duplex reserved r/w r/w r/w ro r/w ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:5 when set, enables duplex mode, allowing simultaneous transmission and reception. 0x0 r/w duplex 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 3 when set, enables the automatic generation of the crc and the placement at the end of the packet. if this bit is not set, the frames placed in the tx fifo will be sent exactly as they are written into the fifo. 0x0 r/w crc 2 when set, enables the automatic padding of packets that do not meet the minimum frame size. 0x0 r/w p aden 1 when set, enables the transmitter . when this bit is 0, the transmitter is disabled. 0x0 r/w txen 0 june 14, 2007 452 luminary micro confidential-advance product information ethernet controller
register 6: ethernet mac data (macda t a), offset 0x010 this register enables software to access the tx and rx fifos. reads from this register return the data stored in the rx fifo from the location indicated by the read pointer . w rites to this register store the data in the tx fifo at the location indicated by the write pointer . the write pointer is then auto-incremented to the next tx fifo location. there is no mechanism for randomly accessing bytes in either the rx or tx fifos. data must be read from the rx fifo sequentially and stored in a buf fer for further processing. once a read has been performed, the data in the fifo cannot be re-read. data must be written to the tx fifo sequentially . if an error is made in placing the frame into the tx fifo, the write pointer can be reset to the start of the tx fifo by writing the txer bit of the maciack register and the data re-written. ethernet mac data (macda t a) base 0x4004.8000 of fset 0x010 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 rxda t a r r r r r r r r r r r r r r r r t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rxda t a r r r r r r r r r r r r r r r r t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field the rxdata bits represent the next four bytes of data stored in the rx fifo. 0x0 r rxda t a 31:0 ethernet mac data (macda t a) base 0x4004.8000 of fset 0x010 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 txda t a w w w w w w w w w w w w w w w w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 txda t a w w w w w w w w w w w w w w w w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field the txdata bits represent the next four bytes of data to place in the tx fifo for transmission. 0x0 w txda t a 31:0 453 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 7: ethernet mac individual address 0 (macia0), offset 0x014 this register enables software to program the first four bytes of the hardware mac address of the network interface card (nic). the 6-byte iar is compared against the incoming destination address fields to determine whether the frame should be received. ethernet mac individual address 0 (macia0) base 0x4004.8000 of fset 0x014 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 macoct3 macoct4 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 macoct1 macoct2 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field the macoct4 bits represent the fourth octet of the mac address used to uniquely identify each ethernet controller . 0x0 r/w macoct4 31:24 the macoct3 bits represent the third octet of the mac address used to uniquely identify each ethernet controller . 0x0 r/w macoct3 23:16 the macoct2 bits represent the second octet of the mac address used to uniquely identify each ethernet controller . 0x0 r/w macoct2 15:8 the macoct1 bits represent the first octet of the mac address used to uniquely identify each ethernet controller . 0x0 r/w macoct1 7:0 june 14, 2007 454 luminary micro confidential-advance product information ethernet controller
register 8: ethernet mac individual address 1 (macia1), offset 0x018 this register enables software to program the last two bytes of the hardware mac address of the network interface card (nic). the 6-byte iar is compared against the incoming destination address fields to determine whether the frame should be received. ethernet mac individual address 1 (macia1) base 0x4004.8000 of fset 0x018 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 macoct5 macoct6 r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:16 the macoct6 bits represent the sixth octet of the mac address used to uniquely identify each ethernet controller . 0x0 r/w macoct6 15:8 the macoct5 bits represent the fifth octet of the mac address used to uniquely identify each ethernet controller . 0x0 r/w macoct5 7:0 455 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 9: ethernet mac threshold (macthr), offset 0x01c this register enables software to set the threshold level at which the transmission of the frame begins. if the thresh bits are set to 0x3f , which is the reset value, transmission does not start until the newtx bit is set in the mactr register . this ef fectively disables the early transmission feature. w riting the thresh bits to any value besides all 1s enables the early transmission feature. once the byte count of data in the tx fifo reaches this level, transmission of the frame begins. when thresh is set to all 0s, transmission of the frame begins after 4 bytes (a single write) are stored in the tx fifo. each increment of the thresh bit field waits for an additional 32 bytes of data (eight writes) to be stored in the tx fifo. therefore, a value of 0x01 would wait for 36 bytes of data to be written while a value of 0x02 would wait for 68 bytes to be written. in general, early transmission starts when: number of bytes 4 ( thresh x 8 + 1) reaching the threshold level has the same ef fect as setting the newtx bit in the mactr register . t ransmission of the frame begins and then the number of bytes indicated by the data length field is sent out on the physical medium. because under-run checking is not performed, it is possible that the tail pointer may reach and pass the write pointer in the tx fifo. this causes indeterminate values to be written to the physical medium rather than the end of the frame. therefore, suf ficient bus bandwidth for writing to the tx fifo must be guaranteed by the software. if a frame smaller than the threshold level needs to be sent, the newtx bit in the mactr register must be set with an explicit write. this initiates the transmission of the frame even though the threshold limit has not been reached. if the threshold level is set too small, it is possible for the transmitter to underrun. if this occurs, the transmit frame will be aborted, and a transmit error will be indicated. ethernet mac threshold (macthr) base 0x4004.8000 of fset 0x01c t ype r/w , reset 0x0000.003f 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 thresh reserved r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:6 the thresh bits represent the early transmit threshold. once the amount of data in the tx fifo exceeds this value, transmission of the packet begins. 0x3f r/w thresh 5:0 june 14, 2007 456 luminary micro confidential-advance product information ethernet controller
register 10: ethernet mac management control (macmctl), offset 0x020 this register enables software to control the transfer of data to and from the mii management registers in the ethernet phy . the address, name, type, reset configuration, and functional description of each of these registers can be found in t able 17-2 on page 445 and mii management register descriptions on page 463 . in order to initiate a read transaction from the mii management registers, the write bit must be written with a 0 during the same cycle that the start bit is written with a 1. in order to initiate a write transaction to the mii management registers, the write bit must be written with a 1 during the same cycle that the start bit is written with a 1. ethernet mac management control (macmctl) base 0x4004.8000 of fset 0x020 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 st ar t write reserved regadr reserved r/w r/w ro r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:8 the regadr bit field represents the mii management register address for the next mii management interface transaction. 0x0 r/w regadr 7:3 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 2 the write bit represents the operation of the next mii management interface transaction. if write is set, the next operation will be a write; otherwise, it will be a read. 0x0 r/w write 1 the start bit represents the initiation of the next mii management interface transaction. when a 1 is written to this bit, the mii register located at regadr will be read ( write =0) or written ( write =1). 0x0 r/w st ar t 0 457 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1 1: ethernet mac management divider (macmdv), offset 0x024 this register enables software to set the clock divider for the management data clock (mdc). this clock is used to synchronize read and write transactions between the system and the mii management registers. the frequency of the mdc clock can be calculated from the following formula: f mdc = f ipclk / (2 * (macmdvr + 1 )) the clock divider must be written with a value that ensures that the mdc clock will not exceed a frequency of 2.5 mhz. ethernet mac management divider (macmdv) base 0x4004.8000 of fset 0x024 t ype r/w , reset 0x0000.0080 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 div reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:8 the div bits are used to set the clock divider for the mdc clock used to transmit data between the mac and phy over the serial mii interface. 0x80 r/w div 7:0 june 14, 2007 458 luminary micro confidential-advance product information ethernet controller
register 12: ethernet mac management address (macmadd), offset 0x028 this register enables software to choose the address of the phy for the next mii management register transaction. ethernet mac management address (macmadd) base 0x4004.8000 of fset 0x028 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:0 459 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 13: ethernet mac management t ransmit data (macmtxd), offset 0x02c this register holds the next value to be written to the mii management registers. ethernet mac management t ransmit data (macmtxd) base 0x4004.8000 of fset 0x02c t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mdtx r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:16 the mdtx bits represent the data that will be written in the next mii management transaction. 0x0 r/w mdtx 15:0 june 14, 2007 460 luminary micro confidential-advance product information ethernet controller
register 14: ethernet mac management receive data (macmrxd), offset 0x030 this register holds the last value read from the mii management registers. ethernet mac management receive data (macmrxd) base 0x4004.8000 of fset 0x030 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mdrx r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:16 the mdrx bits represent the data that was read in the previous mii management transaction. 0x0 r/w mdrx 15:0 461 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 15: ethernet mac number of packets (macnp), offset 0x034 this register holds the number of frames that are currently in the rx fifo. when npr is all 0s, there are no frames in the rx fifo and the rxint bit is not set. when npr is any other value, there is at least one frame in the rx fifo and the rxint bit is set. ethernet mac number of packets (macnp) base 0x4004.8000 of fset 0x034 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 npr reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:6 the npr bits represent the number of packets stored in the rx fifo. while npr is greater than 0, the rxint interrupt will be asserted. 0x0 ro npr 5:0 june 14, 2007 462 luminary micro confidential-advance product information ethernet controller
register 16: ethernet mac t ransmission request (mactr), offset 0x038 this register enables software to initiate the transmission of the frame currently located in the tx fifo to the physical medium. once the frame has been transmitted to the medium from the tx fifo or a transmission error has been encountered, the newtx bit is auto-cleared by the hardware. ethernet mac t ransmission request (mactr) base 0x4004.8000 of fset 0x038 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 newtx reserved r/w ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 31:1 when set, the newtx bit initiates an ethernet transmission once the packet has been placed in the tx fifo. this bit is cleared once the transmission has been completed. if early transmission is being used (see the macthr register), this bit does not need to be set. 0x0 r/w newtx 0 17.6 mii management register descriptions the ieee 802.3 standard specifies a register set for controlling and gathering status from the phy . the registers are collectively known as the mii management registers. all addresses given are absolute. addresses not listed are reserved. 463 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 17: ethernet phy management register 0 C control (mr0), offset 0x00 this register enables software to configure the operation of the phy . the default settings of these registers are designed to initialize the phy to a normal operational mode without configuration. ethernet phy management register 0 C control (mr0) base 0x4004.8000 of fset 0x00 t ype r/w , reset 0x3100 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved col t duplex raneg iso pwrdn anegen speedsl loopbk reset r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 reset registers when set, resets the registers to their default state and reinitializes internal state machines. once the reset operation has completed, this bit is cleared by hardware. 0 r/w reset 15 loopback mode when set, enables the loopback mode of operation. the receive circuitry is isolated from the physical medium and transmissions are sent back through the receive circuitry instead of the medium. 0 r/w loopbk 14 speed select 1: enables the 100 mb/s mode of operation (100base-tx). 0: enables the 10 mb/s mode of operation (10base-t). 1 r/w speedsl 13 auto-negotiation enable when set, enables the auto-negotiation process. 1 r/w anegen 12 power down when set, places the phy into a low-power consuming state. 0 r/w pwrdn 1 1 isolate when set, isolates transmit and receive data paths and ignores all signaling on these buses. 0 r/w iso 10 restart auto-negotiation when set, restarts the auto-negotiation process. once the restart has initiated, this bit is cleared by hardware. 0 r/w raneg 9 june 14, 2007 464 luminary micro confidential-advance product information ethernet controller
description reset t ype name bit/field set duplex mode 1: enables the full-duplex mode of operation. this bit can be set by software in a manual configuration process or by the auto-negotiation process. 0: enables the half-duplex mode of operation. 1 r/w duplex 8 collision t est when set, enables the collision t est mode of operation. the colt bit asserts after the initiation of a transmission and de-asserts once the transmission is halted. 0 r/w col t 7 w rite as 0, ignore on read. 0x00 r/w reserved 6:0 465 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 18: ethernet phy management register 1 C status (mr1), offset 0x01 this register enables software to determine the capabilities of the phy and perform its initialization and operation appropriately . ethernet phy management register 1 C status (mr1) base 0x4004.8000 of fset 0x01 t ype ro, reset 0x7849 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 extd jab link anega rf aul t anegc mfps reserved 10t_h 10t_f 100x_h 100x_f reserved ro rc ro ro rc ro ro ro ro ro ro ro ro ro ro ro t ype 1 0 0 1 0 0 1 0 0 0 0 1 1 1 1 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:15 100base-tx full-duplex mode when set, indicates that the phy is capable of supporting 100base-tx full duplex mode. 1 ro 100x_f 14 100base-tx half-duplex mode when set, indicates that the phy is capable of supporting 100base-tx half-duplex mode. 1 ro 100x_h 13 10base-t full-duplex mode when set, indicates that the phy is capable of 10base-t full-duplex mode. 1 ro 10t_f 12 10base-t half-duplex mode when set, indicates that the phy is capable of supporting 10base-t half-duplex mode. 1 ro 10t_h 1 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 10:7 management frames with preamble suppressed when set, indicates that the management interface is capable of receiving management frames with the preamble suppressed. 1 ro mfps 6 auto-negotiation complete when set, indicates that the auto-negotiation process has been completed and that the extended registers defined by the auto-negotiation protocol are valid. 0 ro anegc 5 june 14, 2007 466 luminary micro confidential-advance product information ethernet controller
description reset t ype name bit/field remote fault when set, indicates that a remote fault condition has been detected. this bit remains set until it is read, even if the condition no longer exists. 0 rc rf aul t 4 auto-negotiation when set, indicates that the phy has the ability to perform auto-negotiation. 1 ro anega 3 link made when set, indicates that a valid link has been established by the phy . 0 ro link 2 jabber condition when set, indicates that a jabber condition has been detected by the phy . this bit remains set until it is read, even if the jabber condition no longer exists. 0 rc jab 1 extended capabilities when set, indicates that the phy provides an extended set of capabilities that can be accessed through the extended register set. 1 ro extd 0 467 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 19: ethernet phy management register 2 C phy identifier 1 (mr2), offset 0x02 this register , along with management register 3, provides a 32-bit value indicating the manufacturer , model, and revision information. ethernet phy management register 2 C phy identifier 1 (mr2) base 0x4004.8000 of fset 0x02 t ype ro, reset 0x000e 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 oui[21:6] ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 organizationally unique identifier[21:6] this field, along with the oui[5:0] field in management register 3 , makes up the organizationally unique identifier indicating the phy manufacturer . 0x000e ro oui[21:6] 15:0 june 14, 2007 468 luminary micro confidential-advance product information ethernet controller
register 20: ethernet phy management register 3 C phy identifier 2 (mr3), offset 0x03 this register , along with management register 2, provides a 32-bit value indicating the manufacturer , model, and revision information. ethernet phy management register 3 C phy identifier 2 (mr3) base 0x4004.8000 of fset 0x03 t ype ro, reset 0x7237 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rn mn oui[5:0] ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 1 1 1 0 1 1 0 0 0 1 0 0 1 1 1 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 organizationally unique identifier[5:0] this field, along with the oui[21:6] field in management register 2 , makes up the organizationally unique identifier indicating the phy manufacturer . 0x1c ro oui[5:0] 15:10 model number the mn field represents the model number of the phy . 0x23 ro mn 9:4 revision number the rn field represents the revision number of the phy . 0x7 ro rn 3:0 469 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 21: ethernet phy management register 4 C auto-negotiation advertisement (mr4), offset 0x04 this register provides the advertised abilities of the phy used during auto-negotiation. bits 12:5 represent the t echnology ability field bits, a[7:0]. this field can be overwritten by software to auto-negotiate to an alternate common technology . w riting to this register has no ef fect until auto-negotiation is re-initiated. ethernet phy management register 4 C auto-negotiation advertisement (mr4) base 0x4004.8000 of fset 0x04 t ype r/w , reset 0x01e1 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 s[4:0] a0 a1 a2 a3 reserved rf reserved np ro ro ro ro ro r/w r/w r/w r/w ro ro ro ro r/w ro ro t ype 1 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 next page when set, indicates the phy is capable of next page exchanges to provide more detailed information on the phy s capabilities. 0 ro np 15 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 14 remote fault when set, indicates to the link partner that a remote fault condition has been encountered. 0 r/w rf 13 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 12:9 t echnology ability field[3] when set, indicates that the phy supports the 100base-tx full-duplex signaling protocol. if software wants to ensure that this mode is not used, this bit can be written to 0 and auto-negotiation re-initiated with the raneg bit. 1 r/w a3 8 t echnology ability field[2] when set, indicates that the phy supports the 100base-t half-duplex signaling protocol. if software wants to ensure that this mode is not used, this bit can be written to 0 and auto-negotiation re-initiated. 1 r/w a2 7 june 14, 2007 470 luminary micro confidential-advance product information ethernet controller
description reset t ype name bit/field t echnology ability field[1] when set, indicates that the phy supports the 10base-t full-duplex signaling protocol. if software wants to ensure that this mode is not used, this bit can be written to 0 and auto-negotiation re-initiated. 1 r/w a1 6 t echnology ability field[0] when set, indicates that the phy supports the 10base-t half-duplex signaling protocol. if software wants to ensure that this mode is not used, this bit can be written to 0 and auto-negotiation re-initiated. 1 r/w a0 5 selector field the s[4:0] field encodes 32 possible messages for communicating between phys. this field is hard-coded to 0x01, indicating that the stellaris ? phy is ieee 802.3 compliant. 0x01 ro s[4:0] 4:0 471 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 22: ethernet phy management register 5 C auto-negotiation link partner base page ability (mr5), offset 0x05 this register provides the advertised abilities of the link partner s phy that are received and stored during auto-negotiation. ethernet phy management register 5 C auto-negotiation link partner base page ability (mr5) base 0x4004.8000 of fset 0x05 t ype ro, reset 0x0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 s[4:0] a[7:0] rf ack np ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 next page when set, indicates that the link partner s phy is capable of next page exchanges to provide more detailed information on the phy s capabilities. 0 ro np 15 acknowledge when set, indicates that the device has successfully received the link partner s advertised abilities during auto-negotiation. 0 ro ack 14 remote fault used as a standard transport mechanism for transmitting simple fault information. 0 ro rf 13 t echnology ability field the a field encodes individual technologies that are supported by the phy . see the mr4 register . 0x00 ro a[7:0] 12:5 selector field the s field encodes possible messages for communicating between phys. meaning v alue reserved 0x00 ieee std 802.3 0x01 ieee std 802.9 islan-16t 0x02 ieee std 802.5 0x03 ieee std 1394 0x04 reserved 0x05 C 0x1f 0x00 ro s[4:0] 4:0 june 14, 2007 472 luminary micro confidential-advance product information ethernet controller
register 23: ethernet phy management register 6 C auto-negotiation expansion (mr6), offset 0x06 this register enables software to determine the auto-negotiation and next page capabilities of the phy and the link partner after auto-negotiation. ethernet phy management register 6 C auto-negotiation expansion (mr6) base 0x4004.8000 of fset 0x06 t ype ro, reset 0x0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 lp anega prx reserved lpnp a pdf reserved ro rc ro ro rc ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:5 parallel detection fault when set, indicates that more than one technology has been detected at link up. this bit is cleared when read. 0 rc pdf 4 link partner is next page able when set, indicates that the link partner is next page able. 0 ro lpnp a 3 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x000 ro reserved 2 new page received when set, indicates that a new page has been received from the link partner and stored in the appropriate location. this bit remains set until the register is read. 0 rc prx 1 link partner is auto-negotiation able when set, indicates that the link partner is auto-negotiation able. 0 ro lp anega 0 473 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 24: ethernet phy management register 16 C v endor-specific (mr16), offset 0x10 this register enables software to configure the operation of vendor specific modes of the phy . ethernet phy management register 16 C v endor-specific (mr16) base 0x4004.8000 of fset 0x10 t ype r/w , reset 0x0140 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 rxcc pcsbp reserved r vspol apol reserved nl10 sqei txhim reserved inpol rptr r/w r/w ro ro r/w r/w ro ro ro ro r/w r/w r/w ro r/w r/w t ype 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 repeater mode when set, enables the repeater mode of operation. in this mode, full-duplex is not allowed and the carrier sense signal only responds to receive activity . if the phy is configured to 10base-t mode, the sqe test function is disabled. 0 r/w rptr 15 interrupt polarity 1: sets the polarity of the phy interrupt to be active high. 0: sets the polarity of the phy interrupt to active low . important: because the media access controller expects active low interrupts from the phy , this bit must always be written with a 0 to ensure proper operation. 0 r/w inpol 14 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 13 t ransmit high impedance mode when set, enables the transmitter high impedance mode. in this mode, the txop and txon transmitter pins are put into a high impedance state. the rxip and rxin pins remain fully functional. 0 r/w txhim 12 sqe inhibit t esting when set, prohibits 10base-t sqe testing. when 0, the sqe testing is performed by generating a collision pulse following the completion of the transmission of a frame. 0 r/w sqei 1 1 june 14, 2007 474 luminary micro confidential-advance product information ethernet controller
description reset t ype name bit/field natural loopback mode when set, enables the 10base-t natural loopback mode. this causes the transmission data received by the phy to be looped back onto the receive data path when 10base-t mode is enabled. 0 r/w nl10 10 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x05 ro reserved 9:6 auto-polarity disable when set, disables the phy s auto-polarity function. if this bit is 0, the phy automatically inverts the received signal due to a wrong polarity connection during auto-negotiation if the phy is in 10base-t mode. 0 r/w apol 5 receive data polarity this bit indicates whether the receive data pulses are being inverted. if the apol bit is 0, then the rvspol bit is read-only and indicates whether the auto polarity circuitry is reversing the polarity . in this case, a 1 in the rvspol bit indicates that the receive data is inverted while a 0 indicates that the receive data is not inverted. if the apol bit is set, then the rvspol bit is writable and software can force the receive data to be inverted. setting rvspol to 1 forces the receive data to be inverted while a 0 does not invert the receive data. 0 r/w r vspol 4 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 3:2 pcs bypass when set, enables the bypass of the pcs and scrambling/descrambling functions in 100base-tx mode. this mode is only valid when auto-negotiation is disabled and 100base-t mode is enabled. 0 r/w pcsbp 1 receive clock control when set, enables the receive clock control power saving mode if the phy is configured in 100base-tx mode. this mode shuts down the receive clock when no data is being received from the physical medium to save power . this mode should not be used when pcsbp is enabled and is automatically disabled when the loopbk bit in the mr0 register is set. 0 r/w rxcc 0 475 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 25: ethernet phy management register 17 C interrupt control/status (mr17), offset 0x1 1 this register provides the means for controlling and observing the events, which trigger a phy interrupt in the macris register . this register can also be used in a polling mode via the mii serial interface as a means to observe key events within the phy via one register address. bits 0 through 7 are status bits, which are each set to logic 1 based on an event. these bits are cleared after the register is read. bits 8 through 15 of this register , when set to logic 1, enable their corresponding bit in the lower byte to signal a phy interrupt in the macris register . ethernet phy management register 17 C interrupt control/status (mr17) base 0x4004.8000 of fset 0x1 1 t ype r/w , reset 0x0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 anegcomp_int rf aul t_int lschg_int lp ack_int pdf_int prx_int rxer_int jabber_int anegcomp_ie rf aul t_ie lschg_ie lp ack_ie pdf_ie prx_ie rxer_ie jabber_ie rc rc rc rc rc rc rc rc r/w r/w r/w r/w r/w r/w r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 jabber interrupt enable when set, enables system interrupts when a jabber condition is detected by the phy . 0 r/w jabber_ie 15 receive error interrupt enable when set, enables system interrupts when a receive error is detected by the phy . 0 r/w rxer_ie 14 page received interrupt enable when set, enables system interrupts when a new page is received by the phy . 0 r/w prx_ie 13 parallel detection fault interrupt enable when set, enables system interrupts when a parallel detection fault is detected by the phy . 0 r/w pdf_ie 12 lp acknowledge interrupt enable when set, enables system interrupts when flp bursts are received with the acknowledge bit during auto-negotiation. 0 r/w lp ack_ie 1 1 link status change interrupt enable when set, enables system interrupts when the link status changes from ok to f ail. 0 r/w lschg_ie 10 june 14, 2007 476 luminary micro confidential-advance product information ethernet controller
description reset t ype name bit/field remote fault interrupt enable when set, enables system interrupts when a remote fault condition is signaled by the link partner . 0 r/w rf aul t_ie 9 auto-negotiation complete interrupt enable when set, enables system interrupts when the auto-negotiation sequence has completed successfully . 0 r/w anegcomp_ie 8 jabber event interrupt when set, indicates that a jabber event has been detected by the 10base-t circuitry . 0 rc jabber_int 7 receive error interrupt when set, indicates that a receive error has been detected by the phy . 0 rc rxer_int 6 page receive interrupt when set, indicates that a new page has been received from the link partner during auto-negotiation. 0 rc prx_int 5 parallel detection fault interrupt when set, indicates that a parallel detection fault has been detected by the phy during the auto-negotiation process. 0 rc pdf_int 4 lp acknowledge interrupt when set, indicates that an flp burst has been received with the acknowledge bit set during auto-negotiation. 0 rc lp ack_int 3 link status change interrupt when set, indicates that the link status has changed from ok to f ail. 0 rc lschg_int 2 remote fault interrupt when set, indicates that a remote fault condition has been signaled by the link partner . 0 rc rf aul t_int 1 auto-negotiation complete interrupt when set, indicates that the auto-negotiation sequence has completed successfully . 0 rc anegcomp_int 0 477 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 26: ethernet phy management register 18 C diagnostic (mr18), offset 0x12 this register enables software to diagnose the results of the previous auto-negotiation. ethernet phy management register 18 C diagnostic (mr18) base 0x4004.8000 of fset 0x12 t ype ro, reset 0x0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved rx_lock rxsd ra te dplx anegf reserved ro ro ro ro ro ro ro ro ro ro ro ro rc ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:13 auto-negotiation failure when set, indicates that no common technology was found during auto-negotiation and has failed. this bit remains set until read. 0 rc anegf 12 duplex mode when set, indicates that full-duplex was the highest common denominator found during the auto-negotiation process. otherwise, half-duplex was the highest common denominator found. 0 ro dplx 1 1 rate when set, indicates that 100base-tx was the highest common denominator found during the auto-negotiation process. otherwise, 10base-tx was the highest common denominator found. 0 ro ra te 10 receive detection when set, indicates that receive signal detection has occurred (in 100base-tx mode) or that manchester encoded data has been detected (in 10base-t mode). 0 ro rxsd 9 receive pll lock when set, indicates that the receive pll has locked onto the receive signal for the selected speed of operation (10base-t or 100base-tx). 0 ro rx_lock 8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 00 ro reserved 7:0 june 14, 2007 478 luminary micro confidential-advance product information ethernet controller
register 27: ethernet phy management register 19 C t ransceiver control (mr19), offset 0x13 this register enables software to set the gain of the transmit output to compensate for transformer loss. ethernet phy management register 19 C t ransceiver control (mr19) base 0x4004.8000 of fset 0x13 t ype r/w , reset 0x4000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved txo[1:0] ro ro ro ro ro ro ro ro ro ro ro ro ro ro r/w r/w t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:16 t ransmit amplitude selection the txo field sets the transmit output amplitude to account for transmit transformer insertion loss. meaning v alue gain set for 0.0db of insertion loss 00 gain set for 0.4db of insertion loss 01 gain set for 0.8db of insertion loss 10 gain set for 1.2db of insertion loss 1 1 1 r/w txo[1:0] 15:14 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0x0 ro reserved 13:0 479 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 28: ethernet phy management register 23 C led configuration (mr23), offset 0x17 this register enables software to select the source that will cause the leds to toggle. ethernet phy management register 23 C led configuration (mr23) base 0x4004.8000 of fset 0x17 t ype r/w , reset 0x0010 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 led0[3:0] led1[3:0] reserved r/w r/w r/w r/w r/w r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 the led1 field selects the source that will toggle the led1 signal. meaning v alue link ok 0000 rx or tx activity (default led1) 0001 tx activity 0010 rx activity 001 1 collision 0100 100base-tx mode 0101 10base-t mode 01 10 full duplex 01 1 1 link ok & blink=rx or tx activity 1000 1 r/w led1[3:0] 7:4 the led0 field selects the source that will toggle the led0 signal. meaning v alue link ok (default led0) 0000 rx or tx activity 0001 tx activity 0010 rx activity 001 1 collision 0100 100base-tx mode 0101 10base-t mode 01 10 full duplex 01 1 1 link ok & blink=rx or tx activity 1000 0 r/w led0[3:0] 3:0 june 14, 2007 480 luminary micro confidential-advance product information ethernet controller
register 29: ethernet phy management register 24 Cmdi/mdix control (mr24), offset 0x18 this register enables software to control the behavior of the mdi/mdix mux and its switching capabilities. ethernet phy management register 24 Cmdi/mdix control (mr24) base 0x4004.8000 of fset 0x18 t ype r/w , reset 0x00c0 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 mdix_sd mdix_cm mdix aut o_sw pd_mode reserved r/w r/w r/w r/w ro r/w r/w r/w ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:8 parallel detection mode when set, enables the parallel detection mode and allows auto-switching to work when auto-negotiation is not enabled. 0 r/w pd_mode 7 auto-switching enable when set, enables auto-switching of the mdi/mdix mux. 0 r/w aut o_sw 6 auto-switching configuration when set, indicates that the mdi/mdix mux is in the crossover (mdix) configuration. when 0, it indicates that the mux is in the pass-through (mdi) configuration. when the auto_sw bit is 1, the mdix bit is read-only . when the auto_sw bit is 0, the mdix bit is read/write and can be configured manually . 0 r/w mdix 5 auto-switching complete when set, indicates that the auto-switching sequence has completed. if 0, it indicates that the sequence has not completed or that auto-switching is disabled. 0 ro mdix_cm 4 auto-switching seed this field provides the initial seed for the switching algorithm. this seed directly af fects the number of attempts [5,4] respectively to write bits [3:0]. a 0 sets the seed to 0x5. 0 r/w mdix_sd 3:0 481 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
18 analog comparators acmp an analog comparator is a peripheral that compares two analog voltages, and provides a logical output that signals the comparison result. the lm3s8938 controller provides three independent integrated analog comparators that can be configured to drive an output or generate an interrupt or adc event. note: not all comparators have the option to drive an output pin. see the comparator operating mode tables for more information. a comparator can compare a test voltage against any one of these voltages: an individual external reference voltage a shared single external reference voltage a shared internal reference voltage the comparator can provide its output to a device pin, acting as a replacement for an analog comparator on the board, or it can be used to signal the application via interrupts or triggers to the adc to cause it to start capturing a sample sequence. the interrupt generation and adc triggering logic is separate. this means, for example, that an interrupt can be generated on a rising edge and the adc triggered on a falling edge. june 14, 2007 482 luminary micro confidential-advance product information analog comparators
18.1 block diagram figure 18-1. analog comparator module block diagram 18.2 functional description important: it is recommended that the digital-input enable (the gpioden bit in the gpio module) for the analog input pin be disabled to prevent excessive current draw from the i/o pads. the comparator compares the vin- and vin+ inputs to produce an output, vout . vin- < vin+, vout = 1 vin- > vin+, vout = 0 as shown in figure 18-2 on page 484 , the input source for vin- is an external input. in addition to an external input, input sources for vin+ can be the +ve input of comparator 0 or an internal reference. 483 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller interr upt c2+ c2- output +v e input (alter nate) +v e input interr upt -v e input ref erence input compar ator 2 a cst a t2 a cctl2 interr upt c1- c1+ output +v e input (alter nate) +v e input interr upt -v e input ref erence input compar ator 1 a cst a t1 a cctl1 c1o v oltage ref a crefctl output +v e input (alter nate) +v e input interr upt -v e input ref erence input compar ator 0 a cst a t0 a cctl0 c0+ inter nal b us interr upt c0- c0o c2o tr igger tr igger tr igger tr igger tr igger tr igger
figure 18-2. structure of comparator unit a comparator is configured through two status/control registers ( acctl and acst a t ). the internal reference is configured through one control register ( acrefctl ). interrupt status and control is configured through three registers ( acmis , acris , and acinten ). the operating modes of the comparators are shown in the comparator operating mode tables. t ypically , the comparator output is used internally to generate controller interrupts. it may also be used to drive an external pin or generate an analog-to-digital converter (adc) trigger . important: certain register bit values must be set before using the analog comparators. the proper pad configuration for the comparator input and output pins are described in the comparator operating mode tables. t able 18-1. comparator 0 operating modes comparator 0 accntl0 adc t rigger interrupt output vin+ vin- asrcp yes yes c0o c0+ c0- 00 yes yes c0o c0+ c0- 01 yes yes c0o v ref c0- 10 yes yes c0o reserved c0- 1 1 t able 18-2. comparator 1 operating modes comparator 1 accntl1 adc t rigger interrupt output vin+ vin- asrcp yes yes c1o/c1+ c1o/c1+ a c1- 00 yes yes c1o/c1+ c0+ c1- 01 yes yes c1o/c1+ v ref c1- 10 yes yes c1o/c1+ reserved c1- 1 1 a. c1o and c1+ signals share a single pin and may only be used as one or the other . june 14, 2007 484 luminary micro confidential-advance product information analog comparators a cst a t a cctl intgen t r iggen 2 1 0 cinv output -v e input +v e input interr upt inter nal b us tr igger +v e input (alter nate) ref erence input
t able 18-3. comparator 2 operating modes comparator 2 accntl2 adc t rigger interrupt output vin+ vin- asrcp yes yes c2o/c2+ c2o/c2+ a c2- 00 yes yes c2o/c2+ c0+ c2- 01 yes yes c2o/c2+ v ref c2- 10 yes yes c2o/c2+ reserved c2- 1 1 a. c2o and c2+ signals share a single pin and may only be used as one or the other . 18.2.1 internal reference programming the structure of the internal reference is shown in figure 18-3 on page 485 . this is controlled by a single configuration register ( acrefctl ). t able 18-4 on page 485 shows the programming options to develop specific internal reference values, to compare an external voltage against a particular voltage generated internally . figure 18-3. comparator internal reference structure t able 18-4. internal reference v oltage and acrefctl field v alues output reference v oltage based on vref field v alue acrefctl register rng bit v alue en bit v alue 0 v (gnd) for any value of vref; however , it is recommended that rng=1 and vref=0 for the least noisy ground reference. rng=x en=0 485 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller 8r r r 8r r r ??? ??? 0 decoder 1 15 14 a vdd en inter nal ref erence vref rng
output reference v oltage based on vref field v alue acrefctl register rng bit v alue en bit v alue t otal resistance in ladder is 32 r. the range of internal reference in this mode is 0.825-2.37 v . rng=0 en=1 t otal resistance in ladder is 24 r. v ref = 0.1375 x v ref the range of internal reference for this mode is 0.0-2.0625 v . rng=1 18.3 initialization and configuration the following example shows how to configure an analog comparator to read back its output value from an internal register . 1. enable the analog comparator 0 clock by writing a value of 0x0010.0000 to the rcgc1 register in the system control module. 2. in the gpio module, enable the gpio port/pin associated with c0- as a gpio input. 3. configure the internal voltage reference to 1.65 v by writing the acrefctl register with the value 0x0000.030c. 4. configure comparator 0 to use the internal voltage reference and to not invert the output on the c0o pin by writing the acctl0 register with the value of 0x0000.040c. 5. delay for some time. 6. read the comparator output value by reading the acst a t0 register s oval value. change the level of the signal input on c0- to see the oval value change. 18.4 register map t able 18-5 on page 487 lists the comparator registers. the of fset listed is a hexadecimal increment to the register s address, relative to the analog comparator base address of 0x4003.c000. june 14, 2007 486 luminary micro confidential-advance product information analog comparators v r e f a v d d r v r e f r t - - - - - - - - - - - - - - - - - = v r e f 0 . 8 2 5 0 . 1 0 3 v r e f + = v r e f a v d d v re f 8 + ( ) 3 2 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - = v r e f a v d d r v r e f r t - - - - - - - - - - - - - - - - - = v r e f a v d d v re f ( ) 2 4 - - - - - - - - - - - - - - - - - - - - - =
t able 18-5. analog comparators register map see page description reset t ype name offset 488 analog comparator masked interrupt status 0x0000.0000 r/w1c acmis 0x00 489 analog comparator raw interrupt status 0x0000.0000 ro acris 0x04 490 analog comparator interrupt enable 0x0000.0000 r/w acinten 0x08 491 analog comparator reference v oltage control 0x0000.0000 r/w acrefctl 0x10 492 analog comparator status 0 0x0000.0000 ro acst a t0 0x20 493 analog comparator control 0 0x0000.0000 r/w acctl0 0x24 492 analog comparator status 1 0x0000.0000 ro acst a t1 0x40 493 analog comparator control 1 0x0000.0000 r/w acctl1 0x44 492 analog comparator status 2 0x0000.0000 ro acst a t2 0x60 493 analog comparator control 2 0x0000.0000 r/w acctl2 0x64 18.5 register descriptions the remainder of this section lists and describes the analog comparator registers, in numerical order by address of fset. 487 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 1: analog comparator masked interrupt status (acmis), offset 0x00 this register provides a summary of the interrupt status (masked) of the comparator . analog comparator masked interrupt status (acmis) base 0x4003.c000 of fset 0x00 t ype r/w1c, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 in0 in1 in2 reserved r/w1c r/w1c r/w1c ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:3 comparator 2 masked interrupt status gives the masked interrupt state of this interrupt. w rite 1 to this bit to clear the pending interrupt. 0 r/w1c in2 2 comparator 1 masked interrupt status gives the masked interrupt state of this interrupt. w rite 1 to this bit to clear the pending interrupt. 0 r/w1c in1 1 comparator 0 masked interrupt status gives the masked interrupt state of this interrupt. w rite 1 to this bit to clear the pending interrupt. 0 r/w1c in0 0 june 14, 2007 488 luminary micro confidential-advance product information analog comparators
register 2: analog comparator raw interrupt status (acris), offset 0x04 this register provides a summary of the interrupt status (raw) of the comparator . analog comparator raw interrupt status (acris) base 0x4003.c000 of fset 0x04 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 in0 in1 in2 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:3 when set, indicates that an interrupt has been generated by comparator 2. 0 ro in2 2 when set, indicates that an interrupt has been generated by comparator 1. 0 ro in1 1 when set, indicates that an interrupt has been generated by comparator 0. 0 ro in0 0 489 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 3: analog comparator interrupt enable (acinten), offset 0x08 this register provides the interrupt enable for the comparator . analog comparator interrupt enable (acinten) base 0x4003.c000 of fset 0x08 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 in0 in1 in2 reserved r/w r/w r/w ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:3 when set, enables the controller interrupt from the comparator 2 output 0 r/w in2 2 when set, enables the controller interrupt from the comparator 1 output. 0 r/w in1 1 when set, enables the controller interrupt from the comparator 0 output. 0 r/w in0 0 june 14, 2007 490 luminary micro confidential-advance product information analog comparators
register 4: analog comparator reference v oltage control (acrefctl), offset 0x10 this register specifies whether the resistor ladder is powered on as well as the range and tap. analog comparator reference v oltage control (acrefctl) base 0x4003.c000 of fset 0x10 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 vref reserved rng en reserved r/w r/w r/w r/w ro ro ro ro r/w r/w ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:10 the en bit specifies whether the resistor ladder is powered on. if 0, the resistor ladder is unpowered. if 1, the resistor ladder is connected to the analog v dd . this bit is reset to 0 so that the internal reference consumes the least amount of power if not used and programmed. 0 r/w en 9 the rng bit specifies the range of the resistor ladder . if 0, the resistor ladder has a total resistance of 32 r. if 1, the resistor ladder has a total resistance of 24 r. 0 r/w rng 8 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 7:4 the vref bit field specifies the resistor ladder tap that is passed through an analog multiplexer . the voltage corresponding to the tap position is the internal reference voltage available for comparison. see t able 18-4 on page 485 for some output reference voltage examples. 0 r/w vref 3:0 491 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
register 5: analog comparator status 0 (acst a t0), offset 0x20 register 6: analog comparator status 1 (acst a t1), offset 0x40 register 7: analog comparator status 2 (acst a t2), offset 0x60 these registers specify the current output value of the comparator . analog comparator status 0 (acst a t0) base 0x4003.c000 of fset 0x20 t ype ro, reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved ov al reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:2 the oval bit specifies the current output value of the comparator . 0 ro ov al 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 0 june 14, 2007 492 luminary micro confidential-advance product information analog comparators
register 8: analog comparator control 0 (acctl0), offset 0x24 register 9: analog comparator control 1 (acctl1), offset 0x44 register 10: analog comparator control 2 (acctl2), offset 0x64 these registers configure the comparator s input and output. analog comparator control 0 (acctl0) base 0x4003.c000 of fset 0x24 t ype r/w , reset 0x0000.0000 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 reserved ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 reserved cinv isen isl v al tsen tsl v al reserved asrcp t oen reserved ro r/w r/w r/w r/w r/w r/w r/w ro r/w r/w r/w ro ro ro ro t ype 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 reset description reset t ype name bit/field software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 31:12 the toen bit enables the adc event transmission to the adc. if 0, the event is suppressed and not sent to the adc. if 1, the event is transmitted to the adc. 0 r/w t oen 1 1 the asrcp field specifies the source of input voltage to the vin+ terminal of the comparator . the encodings for this field are as follows: function asrcp pin value 00 pin value of c0+ 01 internal voltage reference 10 reserved 1 1 0 r/w asrcp 10:9 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 8 the tslval bit specifies the sense value of the input that generates an adc event if in level sense mode. if 0, an adc event is generated if the comparator output is low . otherwise, an adc event is generated if the comparator output is high. 0 r/w tsl v al 7 493 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description reset t ype name bit/field the tsen field specifies the sense of the comparator output that generates an adc event. the sense conditioning is as follows: function tsen level sense, see tslval 00 falling edge 01 rising edge 10 either edge 1 1 0 r/w tsen 6:5 the islval bit specifies the sense value of the input that generates an interrupt if in level sense mode. if 0, an interrupt is generated if the comparator output is low . otherwise, an interrupt is generated if the comparator output is high. 0 r/w isl v al 4 the isen field specifies the sense of the comparator output that generates an interrupt. the sense conditioning is as follows: function isen level sense, see islval 00 falling edge 01 rising edge 10 either edge 1 1 0 r/w isen 3:2 the cinv bit conditionally inverts the output of the comparator . if 0, the output of the comparator is unchanged. if 1, the output of the comparator is inverted prior to being processed by hardware. 0 r/w cinv 1 software should not rely on the value of a reserved bit. t o provide compatibility with future products, the value of a reserved bit should be preserved across a read-modify-write operation. 0 ro reserved 0 june 14, 2007 494 luminary micro confidential-advance product information analog comparators
19 pin diagram figure 19-1 on page 495 shows the pin diagram and pin-to-signal-name mapping. figure 19-1. pin connection diagram 495 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
20 signal t ables the following tables list the signals available for each pin. functionality is enabled by software with the gpioafsel register . important: all multiplexed pins are gpios by default, with the exception of the five jt ag pins ( pb7 and pc[3:0] ) which default to the jt ag functionality . t able 20-1 on page 496 shows the pin-to-signal-name mapping, including functional characteristics of the signals. t able 20-2 on page 500 lists the signals in alphabetical order by signal name. t able 20-3 on page 504 groups the signals by functionality , except for gpios. t able 20-4 on page 508 lists the gpio pins and their alternate functionality . t able 20-1. signals by pin number description buffer t ype pin t ype pin name pin number analog-to-digital converter input 0. analog i adc0 1 analog-to-digital converter input 1. analog i adc1 2 the positive supply (3.3 v) for the analog circuits (adc, analog comparators, etc.). these are separated from vdd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - vdda 3 the ground reference for the analog circuits (adc, analog comparators, etc.). these are separated from gnd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - gnda 4 analog-to-digital converter input 2. analog i adc2 5 analog-to-digital converter input 3. analog i adc3 6 low drop-out regulator output voltage. this pin requires an external capacitor between the pin and gnd of 1 f or greater . when the on-chip ldo is used to provide power to the logic, the ldo pin must also be connected to the vdd25 pins at the board level in addition to the decoupling capacitor(s). power - ldo 7 positive supply for i/o and some logic. power - vdd 8 ground reference for logic and i/o pins. power - gnd 9 can module 0 receive ttl i can0rx 10 gpio port d bit 0 ttl i/o pd0 can module 0 transmit ttl o can0tx 1 1 gpio port d bit 1 ttl i/o pd1 gpio port d bit 2 ttl i/o pd2 12 uar t module 1 receive. when in irda mode, this signal has irda modulation. ttl i u1rx gpio port d bit 3 ttl i/o pd3 13 uar t module 1 transmit. when in irda mode, this signal has irda modulation. ttl o u1tx june 14, 2007 496 luminary micro confidential-advance product information signal t ables
description buffer t ype pin t ype pin name pin number positive supply for most of the logic function, including the processor core and most peripherals. power - vdd25 14 ground reference for logic and i/o pins. power - gnd 15 xt alp of the ethernet phy ttl o xtalpphy 16 xt aln of the ethernet phy ttl i xtalnphy 17 gpio port g bit 1 ttl i/o pg1 18 uar t 2 t ransmit. when in irda mode, this signal has irda modulation. ttl o u2tx gpio port g bit 0 ttl i/o pg0 19 uar t 2 receive. when in irda mode, this signal has irda modulation. ttl i u2rx positive supply for i/o and some logic. power - vdd 20 ground reference for logic and i/o pins. power - gnd 21 analog comparator 2 negative input analog i c2- 22 gpio port c bit 7 ttl i/o pc7 analog comparator positive input analog i c2+ 23 analog comparator 2 output ttl o c2o gpio port c bit 6 ttl i/o pc6 analog comparator positive input analog i c1+ 24 analog comparator 1 output ttl o c1o gpio port c bit 5 ttl i/o pc5 capture/compare/pwm 5 ttl i/o ccp5 25 gpio port c bit 4 ttl i/o pc4 gpio port a bit 0 ttl i/o pa0 26 uar t module 0 receive. when in irda mode, this signal has irda modulation. ttl i u0rx gpio port a bit 1 ttl i/o pa1 27 uar t module 0 transmit. when in irda mode, this signal has irda modulation. ttl o u0tx gpio port a bit 2 ttl i/o pa2 28 ssi module 0 clock ttl i/o ssi0clk gpio port a bit 3 ttl i/o pa3 29 ssi module 0 frame ttl i/o ssi0fss gpio port a bit 4 ttl i/o pa4 30 ssi module 0 receive ttl i ssi0rx gpio port a bit 5 ttl i/o pa5 31 ssi module 0 transmit ttl o ssi0tx positive supply for i/o and some logic. power - vdd 32 ground reference for logic and i/o pins. power - gnd 33 i2c module 1 clock od i/o i2c1scl 34 gpio port a bit 6 ttl i/o pa6 i2c module 1 data od i/o i2c1sda 35 gpio port a bit 7 ttl i/o pa7 497 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description buffer t ype pin t ype pin name pin number vcc of the ethernet phy ttl i vccphy 36 rxin of the ethernet phy analog i rxin 37 positive supply for most of the logic function, including the processor core and most peripherals. power - vdd25 38 ground reference for logic and i/o pins. power - gnd 39 rxip of the ethernet phy analog i rxip 40 gnd of the ethernet phy ttl i gndphy 41 gnd of ethernet phy ttl i gndphy 42 txop of ethernet phy analog o txop 43 positive supply for i/o and some logic. power - vdd 44 ground reference for logic and i/o pins. power - gnd 45 txon of ethernet phy analog o txon 46 gpio port f bit 0 ttl i/o pf0 47 main oscillator crystal input or an external clock reference input. analog i osc0 48 main oscillator crystal output. analog o osc1 49 an external input that brings the processor out of hibernate mode when asserted. od i wake 50 an output that indicates the processor is in hibernate mode. ttl o hib 51 hibernation module oscillator crystal input or an external clock reference input. note that this is either a 4.19-mhz crystal or a 32.768-khz oscillator for the hibernation module r tc. see the clksel bit in the hibctl register . analog i xosc0 52 hibernation module oscillator crystal output. analog o xosc1 53 ground reference for logic and i/o pins. power - gnd 54 power source for the hibernation module. it is normally connected to the positive terminal of a battery and serves as the battery backup/hibernation module power-source supply . power - vbat 55 positive supply for i/o and some logic. power - vdd 56 ground reference for logic and i/o pins. power - gnd 57 mdio of ethernet phy ttl i/o mdio 58 mii led 0 ttl o led0 59 gpio port f bit 3 ttl i/o pf3 mii led 1 ttl o led1 60 gpio port f bit 2 ttl i/o pf2 gpio port f bit 1 ttl i/o pf1 61 positive supply for most of the logic function, including the processor core and most peripherals. power - vdd25 62 ground reference for logic and i/o pins. power - gnd 63 system reset input. ttl i rst 64 june 14, 2007 498 luminary micro confidential-advance product information signal t ables
description buffer t ype pin t ype pin name pin number cpu mode bit 0. input must be set to logic 0 (grounded); other encodings reserved. ttl i/o cmod0 65 capture/compare/pwm 0 ttl i/o ccp0 66 gpio port b bit 0 ttl i/o pb0 capture/compare/pwm 2 ttl i/o ccp2 67 gpio port b bit 1 ttl i/o pb1 positive supply for i/o and some logic. power - vdd 68 ground reference for logic and i/o pins. power - gnd 69 i2c module 0 clock od i/o i2c0scl 70 gpio port b bit 2 ttl i/o pb2 i2c module 0 data od i/o i2c0sda 71 gpio port b bit 3 ttl i/o pb3 capture/compare/pwm 3 ttl i/o ccp3 72 gpio port e bit 0 ttl i/o pe0 gpio port e bit 1 ttl i/o pe1 73 capture/compare/pwm 4 ttl i/o ccp4 74 gpio port e bit 2 ttl i/o pe2 capture/compare/pwm 1 ttl i/o ccp1 75 gpio port e bit 3 ttl i/o pe3 cpu mode bit 1. input must be set to logic 0 (grounded); other encodings reserved. ttl i/o cmod1 76 gpio port c bit 3 ttl i/o pc3 77 jt ag tdo and swo ttl o swo jt ag tdo and swo ttl o tdo gpio port c bit 2 ttl i/o pc2 78 jt ag tdi ttl i tdi gpio port c bit 1 ttl i/o pc1 79 jt ag tms and swdio ttl i/o swdio jt ag tms and swdio ttl i/o tms gpio port c bit 0 ttl i/o pc0 80 jt ag/swd clk ttl i swclk jt ag/swd clk ttl i tck positive supply for i/o and some logic. power - vdd 81 ground reference for logic and i/o pins. power - gnd 82 vcc of the ethernet phy ttl i vccphy 83 vcc of the ethernet phy ttl i vccphy 84 gnd of the ethernet phy ttl i gndphy 85 gnd of the ethernet phy ttl i gndphy 86 ground reference for logic and i/o pins. power - gnd 87 positive supply for most of the logic function, including the processor core and most peripherals. power - vdd25 88 gpio port b bit 7 ttl i/o pb7 89 jt ag trstn ttl i trst 499 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description buffer t ype pin t ype pin name pin number analog comparator 0 positive input analog i c0+ 90 analog comparator 0 output ttl o c0o gpio port b bit 6 ttl i/o pb6 analog comparator 1 negative input analog i c1- 91 gpio port b bit 5 ttl i/o pb5 analog comparator 0 negative input analog i c0- 92 gpio port b bit 4 ttl i/o pb4 positive supply for i/o and some logic. power - vdd 93 ground reference for logic and i/o pins. power - gnd 94 analog-to-digital converter input 7. analog i adc7 95 analog-to-digital converter input 6. analog i adc6 96 the ground reference for the analog circuits (adc, analog comparators, etc.). these are separated from gnd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - gnda 97 the positive supply (3.3 v) for the analog circuits (adc, analog comparators, etc.). these are separated from vdd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - vdda 98 analog-to-digital converter input 5. analog i adc5 99 analog-to-digital converter input 4. analog i adc4 100 t able 20-2. signals by signal name description buffer t ype pin t ype pin number pin name analog-to-digital converter input 0. analog i 1 adc0 analog-to-digital converter input 1. analog i 2 adc1 analog-to-digital converter input 2. analog i 5 adc2 analog-to-digital converter input 3. analog i 6 adc3 analog-to-digital converter input 4. analog i 100 adc4 analog-to-digital converter input 5. analog i 99 adc5 analog-to-digital converter input 6. analog i 96 adc6 analog-to-digital converter input 7. analog i 95 adc7 analog comparator 0 positive input analog i 90 c0+ analog comparator 0 negative input analog i 92 c0- analog comparator 0 output ttl o 90 c0o analog comparator positive input analog i 24 c1+ analog comparator 1 negative input analog i 91 c1- analog comparator 1 output ttl o 24 c1o analog comparator positive input analog i 23 c2+ analog comparator 2 negative input analog i 22 c2- analog comparator 2 output ttl o 23 c2o can module 0 receive ttl i 10 can0rx can module 0 transmit ttl o 1 1 can0tx june 14, 2007 500 luminary micro confidential-advance product information signal t ables
description buffer t ype pin t ype pin number pin name capture/compare/pwm 0 ttl i/o 66 ccp0 capture/compare/pwm 1 ttl i/o 75 ccp1 capture/compare/pwm 2 ttl i/o 67 ccp2 capture/compare/pwm 3 ttl i/o 72 ccp3 capture/compare/pwm 4 ttl i/o 74 ccp4 capture/compare/pwm 5 ttl i/o 25 ccp5 cpu mode bit 0. input must be set to logic 0 (grounded); other encodings reserved. ttl i/o 65 cmod0 cpu mode bit 1. input must be set to logic 0 (grounded); other encodings reserved. ttl i/o 76 cmod1 ground reference for logic and i/o pins. power - 9 gnd ground reference for logic and i/o pins. power - 15 gnd ground reference for logic and i/o pins. power - 21 gnd ground reference for logic and i/o pins. power - 33 gnd ground reference for logic and i/o pins. power - 39 gnd ground reference for logic and i/o pins. power - 45 gnd ground reference for logic and i/o pins. power - 54 gnd ground reference for logic and i/o pins. power - 57 gnd ground reference for logic and i/o pins. power - 63 gnd ground reference for logic and i/o pins. power - 69 gnd ground reference for logic and i/o pins. power - 82 gnd ground reference for logic and i/o pins. power - 87 gnd ground reference for logic and i/o pins. power - 94 gnd the ground reference for the analog circuits (adc, analog comparators, etc.). these are separated from gnd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - 4 gnda the ground reference for the analog circuits (adc, analog comparators, etc.). these are separated from gnd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - 97 gnda gnd of the ethernet phy ttl i 41 gndphy gnd of ethernet phy ttl i 42 gndphy gnd of the ethernet phy ttl i 85 gndphy gnd of the ethernet phy ttl i 86 gndphy an output that indicates the processor is in hibernate mode. ttl o 51 hib i2c module 0 clock od i/o 70 i2c0scl i2c module 0 data od i/o 71 i2c0sda i2c module 1 clock od i/o 34 i2c1scl i2c module 1 data od i/o 35 i2c1sda 501 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description buffer t ype pin t ype pin number pin name low drop-out regulator output voltage. this pin requires an external capacitor between the pin and gnd of 1 f or greater . when the on-chip ldo is used to provide power to the logic, the ldo pin must also be connected to the vdd25 pins at the board level in addition to the decoupling capacitor(s). power - 7 ldo mii led 0 ttl o 59 led0 mii led 1 ttl o 60 led1 mdio of ethernet phy ttl i/o 58 mdio main oscillator crystal input or an external clock reference input. analog i 48 osc0 main oscillator crystal output. analog o 49 osc1 gpio port a bit 0 ttl i/o 26 pa0 gpio port a bit 1 ttl i/o 27 pa1 gpio port a bit 2 ttl i/o 28 pa2 gpio port a bit 3 ttl i/o 29 pa3 gpio port a bit 4 ttl i/o 30 pa4 gpio port a bit 5 ttl i/o 31 pa5 gpio port a bit 6 ttl i/o 34 pa6 gpio port a bit 7 ttl i/o 35 pa7 gpio port b bit 0 ttl i/o 66 pb0 gpio port b bit 1 ttl i/o 67 pb1 gpio port b bit 2 ttl i/o 70 pb2 gpio port b bit 3 ttl i/o 71 pb3 gpio port b bit 4 ttl i/o 92 pb4 gpio port b bit 5 ttl i/o 91 pb5 gpio port b bit 6 ttl i/o 90 pb6 gpio port b bit 7 ttl i/o 89 pb7 gpio port c bit 0 ttl i/o 80 pc0 gpio port c bit 1 ttl i/o 79 pc1 gpio port c bit 2 ttl i/o 78 pc2 gpio port c bit 3 ttl i/o 77 pc3 gpio port c bit 4 ttl i/o 25 pc4 gpio port c bit 5 ttl i/o 24 pc5 gpio port c bit 6 ttl i/o 23 pc6 gpio port c bit 7 ttl i/o 22 pc7 gpio port d bit 0 ttl i/o 10 pd0 gpio port d bit 1 ttl i/o 1 1 pd1 gpio port d bit 2 ttl i/o 12 pd2 gpio port d bit 3 ttl i/o 13 pd3 gpio port e bit 0 ttl i/o 72 pe0 gpio port e bit 1 ttl i/o 73 pe1 gpio port e bit 2 ttl i/o 74 pe2 gpio port e bit 3 ttl i/o 75 pe3 june 14, 2007 502 luminary micro confidential-advance product information signal t ables
description buffer t ype pin t ype pin number pin name gpio port f bit 0 ttl i/o 47 pf0 gpio port f bit 1 ttl i/o 61 pf1 gpio port f bit 2 ttl i/o 60 pf2 gpio port f bit 3 ttl i/o 59 pf3 gpio port g bit 0 ttl i/o 19 pg0 gpio port g bit 1 ttl i/o 18 pg1 system reset input. ttl i 64 rst rxin of the ethernet phy analog i 37 rxin rxip of the ethernet phy analog i 40 rxip ssi module 0 clock ttl i/o 28 ssi0clk ssi module 0 frame ttl i/o 29 ssi0fss ssi module 0 receive ttl i 30 ssi0rx ssi module 0 transmit ttl o 31 ssi0tx jt ag/swd clk ttl i 80 swclk jt ag tms and swdio ttl i/o 79 swdio jt ag tdo and swo ttl o 77 swo jt ag/swd clk ttl i 80 tck jt ag tdi ttl i 78 tdi jt ag tdo and swo ttl o 77 tdo jt ag tms and swdio ttl i/o 79 tms jt ag trstn ttl i 89 trst txon of ethernet phy analog o 46 txon txop of ethernet phy analog o 43 txop uar t module 0 receive. when in irda mode, this signal has irda modulation. ttl i 26 u0rx uar t module 0 transmit. when in irda mode, this signal has irda modulation. ttl o 27 u0tx uar t module 1 receive. when in irda mode, this signal has irda modulation. ttl i 12 u1rx uar t module 1 transmit. when in irda mode, this signal has irda modulation. ttl o 13 u1tx uar t 2 receive. when in irda mode, this signal has irda modulation. ttl i 19 u2rx uar t 2 t ransmit. when in irda mode, this signal has irda modulation. ttl o 18 u2tx power source for the hibernation module. it is normally connected to the positive terminal of a battery and serves as the battery backup/hibernation module power-source supply . power - 55 vbat vcc of the ethernet phy ttl i 36 vccphy vcc of the ethernet phy ttl i 83 vccphy vcc of the ethernet phy ttl i 84 vccphy positive supply for i/o and some logic. power - 8 vdd positive supply for i/o and some logic. power - 20 vdd positive supply for i/o and some logic. power - 32 vdd 503 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description buffer t ype pin t ype pin number pin name positive supply for i/o and some logic. power - 44 vdd positive supply for i/o and some logic. power - 56 vdd positive supply for i/o and some logic. power - 68 vdd positive supply for i/o and some logic. power - 81 vdd positive supply for i/o and some logic. power - 93 vdd positive supply for most of the logic function, including the processor core and most peripherals. power - 14 vdd25 positive supply for most of the logic function, including the processor core and most peripherals. power - 38 vdd25 positive supply for most of the logic function, including the processor core and most peripherals. power - 62 vdd25 positive supply for most of the logic function, including the processor core and most peripherals. power - 88 vdd25 the positive supply (3.3 v) for the analog circuits (adc, analog comparators, etc.). these are separated from vdd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - 3 vdda the positive supply (3.3 v) for the analog circuits (adc, analog comparators, etc.). these are separated from vdd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - 98 vdda an external input that brings the processor out of hibernate mode when asserted. od i 50 wake hibernation module oscillator crystal input or an external clock reference input. note that this is either a 4.19-mhz crystal or a 32.768-khz oscillator for the hibernation module r tc. see the clksel bit in the hibctl register . analog i 52 xosc0 hibernation module oscillator crystal output. analog o 53 xosc1 xt aln of the ethernet phy ttl i 17 xtalnphy xt alp of the ethernet phy ttl o 16 xtalpphy t able 20-3. signals by function, except for gpio description buffer t ype pin t ype pin number pin name function analog-to-digital converter input 0. analog i 1 adc0 adc analog-to-digital converter input 1. analog i 2 adc1 analog-to-digital converter input 2. analog i 5 adc2 analog-to-digital converter input 3. analog i 6 adc3 analog-to-digital converter input 4. analog i 100 adc4 analog-to-digital converter input 5. analog i 99 adc5 analog-to-digital converter input 6. analog i 96 adc6 analog-to-digital converter input 7. analog i 95 adc7 june 14, 2007 504 luminary micro confidential-advance product information signal t ables
description buffer t ype pin t ype pin number pin name function analog comparator 0 positive input analog i 90 c0+ analog comparators analog comparator 0 negative input analog i 92 c0- analog comparator 0 output ttl o 90 c0o analog comparator positive input analog i 24 c1+ analog comparator 1 negative input analog i 91 c1- analog comparator 1 output ttl o 24 c1o analog comparator positive input analog i 23 c2+ analog comparator 2 negative input analog i 22 c2- analog comparator 2 output ttl o 23 c2o can module 0 receive ttl i 10 can0rx controller area network can module 0 transmit ttl o 1 1 can0tx gnd of the ethernet phy ttl i 41 gndphy ethernet phy gnd of ethernet phy ttl i 42 gndphy gnd of the ethernet phy ttl i 85 gndphy gnd of the ethernet phy ttl i 86 gndphy mii led 0 ttl o 59 led0 mii led 1 ttl o 60 led1 mdio of ethernet phy ttl i/o 58 mdio rxin of the ethernet phy analog i 37 rxin rxip of the ethernet phy analog i 40 rxip txon of ethernet phy analog o 46 txon txop of ethernet phy analog o 43 txop vcc of the ethernet phy ttl i 36 vccphy vcc of the ethernet phy ttl i 83 vccphy vcc of the ethernet phy ttl i 84 vccphy xt aln of the ethernet phy ttl i 17 xtalnphy xt alp of the ethernet phy ttl o 16 xtalpphy capture/compare/pwm 0 ttl i/o 66 ccp0 general-purpose t imers capture/compare/pwm 1 ttl i/o 75 ccp1 capture/compare/pwm 2 ttl i/o 67 ccp2 capture/compare/pwm 3 ttl i/o 72 ccp3 capture/compare/pwm 4 ttl i/o 74 ccp4 capture/compare/pwm 5 ttl i/o 25 ccp5 i2c module 0 clock od i/o 70 i2c0scl i2c i2c module 0 data od i/o 71 i2c0sda i2c module 1 clock od i/o 34 i2c1scl i2c module 1 data od i/o 35 i2c1sda 505 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description buffer t ype pin t ype pin number pin name function jt ag/swd clk ttl i 80 swclk jt ag/swd/swo jt ag tms and swdio ttl i/o 79 swdio jt ag tdo and swo ttl o 77 swo jt ag/swd clk ttl i 80 tck jt ag tdi ttl i 78 tdi jt ag tdo and swo ttl o 77 tdo jt ag tms and swdio ttl i/o 79 tms june 14, 2007 506 luminary micro confidential-advance product information signal t ables
description buffer t ype pin t ype pin number pin name function ground reference for logic and i/o pins. power - 9 gnd power ground reference for logic and i/o pins. power - 15 gnd ground reference for logic and i/o pins. power - 21 gnd ground reference for logic and i/o pins. power - 33 gnd ground reference for logic and i/o pins. power - 39 gnd ground reference for logic and i/o pins. power - 45 gnd ground reference for logic and i/o pins. power - 54 gnd ground reference for logic and i/o pins. power - 57 gnd ground reference for logic and i/o pins. power - 63 gnd ground reference for logic and i/o pins. power - 69 gnd ground reference for logic and i/o pins. power - 82 gnd ground reference for logic and i/o pins. power - 87 gnd ground reference for logic and i/o pins. power - 94 gnd the ground reference for the analog circuits (adc, analog comparators, etc.). these are separated from gnd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - 4 gnda the ground reference for the analog circuits (adc, analog comparators, etc.). these are separated from gnd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - 97 gnda an output that indicates the processor is in hibernate mode. ttl o 51 hib low drop-out regulator output voltage. this pin requires an external capacitor between the pin and gnd of 1 f or greater . when the on-chip ldo is used to provide power to the logic, the ldo pin must also be connected to the vdd25 pins at the board level in addition to the decoupling capacitor(s). power - 7 ldo power source for the hibernation module. it is normally connected to the positive terminal of a battery and serves as the battery backup/hibernation module power-source supply . power - 55 vbat positive supply for i/o and some logic. power - 8 vdd positive supply for i/o and some logic. power - 20 vdd positive supply for i/o and some logic. power - 32 vdd positive supply for i/o and some logic. power - 44 vdd positive supply for i/o and some logic. power - 56 vdd positive supply for i/o and some logic. power - 68 vdd positive supply for i/o and some logic. power - 81 vdd positive supply for i/o and some logic. power - 93 vdd positive supply for most of the logic function, including the processor core and most peripherals. power - 14 vdd25 positive supply for most of the logic function, including the processor core and most peripherals. power - 38 vdd25 positive supply for most of the logic function, including the processor core and most peripherals. power - 62 vdd25 507 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
description buffer t ype pin t ype pin number pin name function vdd25 positive supply for most of the logic function, including the processor core and most peripherals. power - 88 the positive supply (3.3 v) for the analog circuits (adc, analog comparators, etc.). these are separated from vdd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - 3 vdda the positive supply (3.3 v) for the analog circuits (adc, analog comparators, etc.). these are separated from vdd to minimize the electrical noise contained on vdd from af fecting the analog functions. power - 98 vdda an external input that brings the processor out of hibernate mode when asserted. od i 50 wake ssi module 0 clock ttl i/o 28 ssi0clk ssi ssi module 0 frame ttl i/o 29 ssi0fss ssi module 0 receive ttl i 30 ssi0rx ssi module 0 transmit ttl o 31 ssi0tx cpu mode bit 0. input must be set to logic 0 (grounded); other encodings reserved. ttl i/o 65 cmod0 system control & clocks cpu mode bit 1. input must be set to logic 0 (grounded); other encodings reserved. ttl i/o 76 cmod1 main oscillator crystal input or an external clock reference input. analog i 48 osc0 main oscillator crystal output. analog o 49 osc1 system reset input. ttl i 64 rst jt ag trstn ttl i 89 trst hibernation module oscillator crystal input or an external clock reference input. note that this is either a 4.19-mhz crystal or a 32.768-khz oscillator for the hibernation module r tc. see the clksel bit in the hibctl register . analog i 52 xosc0 hibernation module oscillator crystal output. analog o 53 xosc1 uar t module 0 receive. when in irda mode, this signal has irda modulation. ttl i 26 u0rx uar t uar t module 0 transmit. when in irda mode, this signal has irda modulation. ttl o 27 u0tx uar t module 1 receive. when in irda mode, this signal has irda modulation. ttl i 12 u1rx uar t module 1 transmit. when in irda mode, this signal has irda modulation. ttl o 13 u1tx uar t 2 receive. when in irda mode, this signal has irda modulation. ttl i 19 u2rx uar t 2 t ransmit. when in irda mode, this signal has irda modulation. ttl o 18 u2tx t able 20-4. gpio pins and alternate functions multiplexed function multiplexed function pin number gpio pin u0rx 26 pa0 june 14, 2007 508 luminary micro confidential-advance product information signal t ables
multiplexed function multiplexed function pin number gpio pin u0tx 27 pa1 ssi0clk 28 pa2 ssi0fss 29 pa3 ssi0rx 30 pa4 ssi0tx 31 pa5 i2c1scl 34 pa6 i2c1sda 35 pa7 ccp0 66 pb0 ccp2 67 pb1 i2c0scl 70 pb2 i2c0sda 71 pb3 c0- 92 pb4 c1- 91 pb5 c0o c0+ 90 pb6 trst 89 pb7 swclk tck 80 pc0 swdio tms 79 pc1 tdi 78 pc2 swo tdo 77 pc3 ccp5 25 pc4 c1o c1+ 24 pc5 c2o c2+ 23 pc6 c2- 22 pc7 can0rx 10 pd0 can0tx 1 1 pd1 u1rx 12 pd2 u1tx 13 pd3 ccp3 72 pe0 73 pe1 ccp4 74 pe2 ccp1 75 pe3 47 pf0 61 pf1 led1 60 pf2 led0 59 pf3 u2rx 19 pg0 u2tx 18 pg1 509 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
21 operating characteristics t able 21-1. t emperature characteristics unit v alue symbol characteristic c -40 to +85 t a operating temperature range a a. maximum storage temperature is 150c. t able 21-2. thermal characteristics unit v alue symbol characteristic c/w 55.3 ja thermal resistance (junction to ambient) a c t a + (p a vg ? ja ) t j a verage junction temperature b a. junction to ambient thermal resistance ja numbers are determined by a package simulator . b. power dissipation is a function of temperature. june 14, 2007 510 luminary micro confidential-advance product information operating characteristics
22 electrical characteristics 22.1 dc characteristics 22.1.1 maximum ratings the maximum ratings are the limits to which the device can be subjected without permanently damaging the device. note: the device is not guaranteed to operate properly at the maximum ratings. t able 22-1. maximum ratings unit v alue symbol characteristic a max min v 4 0 v dd i/o supply voltage (v dd ) v 4 0 v dd25 core supply voltage (v dd25 ) v 4 0 v dda analog supply voltage (v dda ) v 4 0 v ba t battery supply voltage (v ba t ) v 4 0 v ccphy ethernet phy supply voltage (v ccphy ) v 5.5 -0.3 v in input voltage ma 25 - i maximum current per output pins a. v oltages are measured with respect to gnd. important: this device contains circuitry to protect the inputs against damage due to high-static voltages or electric fields; however , it is advised that normal precautions be taken to avoid application of any voltage higher than maximum-rated voltages to this high-impedance circuit. reliability of operation is enhanced if unused inputs are connected to an appropriate logic voltage level (for example, either gnd or v dd ). 22.1.2 recommended dc operating conditions t able 22-2. recommended dc operating conditions unit max nom min parameter name parameter v 3.6 3.3 3.0 i/o supply voltage v dd v 2.75 2.5 2.25 core supply voltage v dd25 v 3.6 3.3 3.0 analog supply voltage v dda v 3.6 3.0 2.3 battery supply voltage v ba t v 3.6 3.3 3.0 ethernet phy supply voltage v ccphy v 5.0 - 2.0 high-level input voltage v ih v 1.3 - -0.3 low-level input voltage v il v v dd - 0.8 * v dd high-level input voltage for schmitt trigger inputs v sih v 0.2 * v dd - 0 low-level input voltage for schmitt trigger inputs v sil v - - 2.4 high-level output voltage v oh v 0.4 - - low-level output voltage v ol 51 1 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
unit max nom min parameter name parameter high-level source current, v oh =2.4 v i oh ma - - 2.0 2-ma drive ma - - 4.0 4-ma drive ma - - 8.0 8-ma drive low-level sink current, v ol =0.4 v i ol ma - - 2.0 2-ma drive ma - - 4.0 4-ma drive ma - - 8.0 8-ma drive 22.1.3 on-chip low drop-out (ldo) regulator characteristics t able 22-3. ldo regulator characteristics unit max nom min parameter name parameter v 2.75 2.5 2.25 programmable internal (logic) power supply output value v ldoout % - 2% - output voltage accuracy s 100 - - power-on time t pon s 200 - - t ime on t on s 100 - - t ime of f t off mv - 50 - step programming incremental voltage v step f - 1 - external filter capacitor size for internal power supply c ldo 22.1.4 power specifications the power measurements specified in the tables that follow are run on the core processor using sram with the following specifications (except as noted): v dd = 3.3 v v dd25 = 2.50 v v ba t = 3.0 v v dda = 3.3 v v ddphy = 3.3 v t emperature = 25c clock source (mosc) =3.579545 mhz crystal oscillator main oscillator (mosc) = enabled internal oscillator (iosc) = disabled june 14, 2007 512 luminary micro confidential-advance product information electrical characteristics
22.1.5 flash memory characteristics t able 22-4. flash memory characteristics unit max nom min parameter name parameter cycles - 100,000 10,000 number of guaranteed program/erase cycles before failure a pe cyc years - - 10 data retention at average operating temperature of 85?c t ret s - - 20 w ord program time t prog ms - - 20 page erase time t erase ms - - 200 mass erase time t me a. a program/erase cycle is defined as switching the bits from 1-> 0 -> 1. 22.2 ac characteristics 22.2.1 load conditions unless otherwise specified, the following conditions are true for all timing measurements. t iming measurements are for 4-ma drive strength. figure 22-1. load conditions 22.2.2 clocks t able 22-5. phase locked loop (pll) characteristics unit max nom min parameter name parameter mhz 8.192 - 3.579545 crystal reference a f ref_crystal mhz 8.192 - 3.579545 external clock reference a f ref_ext mhz - 400 - pll frequency b f pll ms 0.5 - - pll lock time t ready a. the exact value is determined by the crystal value programmed into the xtal field of the run-mode clock configuration (rcc) register . b. pll frequency is automatically calculated by the hardware based on the xtal field of the rcc register . t able 22-6. clock characteristics unit max nom min parameter name parameter mhz 15.6 12 8.4 internal 12 mhz oscillator frequency f iosc khz 39 30 21 internal 30 khz oscillator frequency f iosc30khz mhz - 4.194304 - hibernation module oscillator frequency f xosc mhz - 4.194304 - crystal reference for hibernation oscillator f xosc_xt al khz - 32.768 - external clock reference for hibernation module f xosc_ext 513 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller c l = 50 pf gnd pin
unit max nom min parameter name parameter mhz 8 - 1 main oscillator frequency f mosc ns 1000 - 125 main oscillator period t mosc_per mhz 8 - 1 crystal reference using the main oscillator (pll in byp ass mode) a f ref_crystal_bypass mhz 50 - 0 external clock reference (pll in byp ass mode) a f ref_ext_bypass mhz 50 - 0 system clock f system_clock a. the adc must be clocked from the pll or directly from a 14-mhz to 18-mhz clock source to operate properly . t able 22-7. crystal characteristics units v alue parameter name mhz 3.5 4 6 8 frequency ppm 50 50 50 50 frequency tolerance ppm/yr 5 5 5 5 aging parallel parallel parallel parallel oscillation mode ppm 25 25 25 25 t emperature stability (0 - 85 c) pf 63.5 55.6 37.0 27.8 motional capacitance (typ) mh 32.7 28.6 19.1 14.3 motional inductance (typ) ? 220 200 160 120 equivalent series resistance (max) pf 10 10 10 10 shunt capacitance (max) pf 16 16 16 16 load capacitance (typ) w 100 100 100 100 drive level (typ) 22.2.3 t emperature sensor t able 22-8. t emperature sensor characteristics unit max nom min parameter name parameter v 2.7 - 0.3 output voltage v tso ?c 3.5 - - output voltage temperature accuracy t tserr ?c 1 - - output temperature nonlinearity t tsnl 22.2.4 analog-to-digital converter t able 22-9. adc characteristics unit max nom min parameter name parameter v 3.0 - - maximum single-ended, full-scale analog input voltage v adcin v 0 - - minimum single-ended, full-scale analog input voltage v 1.5 - - maximum dif ferential, full-scale analog input voltage v -1.5 - - minimum dif ferential, full-scale analog input voltage pf - 1 - equivalent input capacitance c adcin bits - 10 - resolution n mhz 18 16 14 adc internal clock frequency f adc t adc cycles a 16 - - conversion time t adcconv k samples/s 1 125 1000 875 conversion rate f adcconv june 14, 2007 514 luminary micro confidential-advance product information electrical characteristics
unit max nom min parameter name parameter lsb 1 - - integral nonlinearity inl lsb 1 - - dif ferential nonlinearity dnl lsb 1 - - of fset off lsb 1 - - gain gain a. t adc = 1/f adc clock 22.2.5 analog comparator t able 22-10. analog comparator characteristics unit max nom min parameter name parameter mv 25 10 - input of fset voltage v os v v dd -1.5 - 0 input common mode voltage range v cm db - - 50 common mode rejection ratio c mrr s 1 - - response time t r t s 10 - - comparator mode change to output v alid t mc t able 22-1 1. analog comparator v oltage reference characteristics unit max nom min parameter name parameter lsb - v dd /32 - resolution high range r hr lsb - v dd /24 - resolution low range r lr lsb 1/2 - - absolute accuracy high range a hr lsb 1/4 - - absolute accuracy low range a lr 22.2.6 i 2 c t able 22-12. i 2 c characteristics unit max nom min parameter name parameter parameter no. system clocks - - 36 start condition hold time t sch i1 a system clocks - - 36 clock low period t lp i2 a ns (see note b) - - i2cscl / i2csda rise time (v il =0.5 v to v ih =2.4 v) t sr t i3 b system clocks - - 2 data hold time t dh i4 a ns 10 9 - i2cscl / i2csda fall time (v ih =2.4 v to v il =0.5 v) t sft i5 c system clocks - - 24 clock high time t ht i6 a system clocks - - 18 data setup time t ds i7 a system clocks - - 36 start condition setup time (for repeated start condition only) t scsr i8 a system clocks - - 24 stop condition setup time t scs i9 a a. v alues depend on the value programmed into the tpr bit in the i 2 c master t imer period (i2cmtpr) register; a tpr programmed for the maximum i2cscl frequency (tpr=0x2) results in a minimum output timing as shown in the table above. the i 2 c interface is designed to scale the actual data transition time to move it to the middle of the i2cscl low period. the actual position is af fected by the value programmed into the tpr ; however , the numbers given in the above values are minimum values. b. because i2cscl and i2csda are open-drain-type outputs, which the controller can only actively drive low , the time i2cscl or i2csda takes to reach a high level depends on external signal capacitance and pull-up resistor values. c. specified at a nominal 50 pf load. 515 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
figure 22-2. i 2 c t iming 22.2.7 ethernet controller t able 22-13. 100base-tx t ransmitter characteristics a unit max nom min parameter name mvpk 1050 - 950 peak output amplitude mvpk 1.02 - 0.98 output amplitude symmetry % 5 - - output overshoot ns 5 - 3 rise/fall time ps 500 - - rise/fall time imbalance ps - - - duty cycle distortion ns 1.4 - - jitter a. measured at the line side of the transformer . t able 22-14. 100base-tx t ransmitter characteristics (informative) a unit max nom min parameter name db - - 16 return loss s - - 350 open-circuit inductance a. the specifications in this table are included for information only . they are mainly a function of the external transformer and termination resistors used for measurements. t able 22-15. 100base-tx receiver characteristics unit max nom min parameter name mvppd 700 600 signal detect assertion threshold mvppd - 425 350 signal detect de-assertion threshold k? - - 20 dif ferential input resistance ns - - 4 jitter tolerance (pk-pk) % +75 - -75 baseline wander tracking s 1000 - - signal detect assertion time s 4 - - signal detect de-assertion time t able 22-16. 10base-t t ransmitter characteristics a unit max nom min parameter name v 2.8 - 2.2 peak dif ferential output signal db - - 27 harmonic content ns - 100 - link pulse width june 14, 2007 516 luminary micro confidential-advance product information electrical characteristics i2cscl i2csda i1 i2 i4 i6 i7 i8 i5 i3 i9
unit max nom min parameter name ns - 300 350 - start-of-idle pulse width a. the manchester-encoded data pulses, the link pulse and the start-of-idle pulse are tested against the templates and using the procedures found in clause 14 of ieee 802.3 . t able 22-17. 10base-t t ransmitter characteristics (informative) a unit max nom min parameter name db - - 15 output return loss db - - 29-17log(f/10) output impedance balance mv 50 - - peak common-mode output voltage mv 100 - - common-mode rejection ns 1 - - common-mode rejection jitter a. the specifications in this table are included for information only . they are mainly a function of the external transformer and termination resistors used for measurements. t able 22-18. 10base-t receiver characteristics unit max nom min parameter name bt - 10 - dll phase acquisition time ns - - 30 jitter tolerance (pk-pk) mvppd 700 600 500 input squelched threshold mvppd 425 350 275 input unsquelched threshold k? - 20 - dif ferential input resistance - - 10 -10 - bit error ratio v - - 25 common-mode rejection t able 22-19. isolation t ransformers a condition v alue name +/- 5% 1 ct : 1 ct t urns ratio @ 10 mv , 10 khz 350 uh (min) open-circuit inductance @ 1 mhz (min) 0.40 uh (max) leakage inductance 25 pf (max) inter-winding capacitance 0.9 ohm (max) dc resistance 0-65 mhz 0.4 db (typ) insertion loss v rms 1500 hipot a. t wo simple 1:1 isolation transformers are required at the line interface. t ransformers with integrated common-mode chokes are recommended for exceeding fcc requirements. this table gives the recommended line transformer characteristics. note: the 100base-tx amplitude specifications assume a transformer loss of 0.4 db. for the transmit line transformer with higher insertion losses, up to 1.2 db of insertion loss can be compensated by selecting the appropriate setting in the t ransmit amplitude selection ( txo ) bits in the mr19 register . 517 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
t able 22-20. ethernet reference crystal a condition v alue name mhz 25.00000 frequency pf 4 c load capacitance b ppm 50 frequency tolerance ppm/yr 2 aging ppm 5 t emperature stability (0 to 70) parallel resonance, fundamental mode oscillation mode parameters at 25 c 2 c; drive level = 0.5 mw w 50-100 drive level (typ) pf 10 shunt capacitance (max) ff 10 motional capacitance (min) ? 60 serious resistance (max) > 5 db below main within 500 khz spurious response (max) a. if the internal crystal oscillator is used, select a crystal with the following characteristics. b. equivalent dif ferential capacitance across xtlp/xtln. c. if crystal with a larger load is used, external shunt capacitors to ground should be added to make up the equivalent capacitance dif ference. figure 22-3. external xtlp oscillator characteristics t able 22-21. external xtlp oscillator characteristics unit max nom min symbol parameter name - 0.8 - - xtln il v xtln input low v oltage - - 25.0 - xtlp f xtlp frequency a - - 40 - t clkper xtlp period b % 60 60 - 40 40 xtlp dc xtlp duty cycle ns 4.0 - - t r , t f rise/fall t ime ns 0.1 - - absolute jitter a. ieee 802.3 frequency tolerance 50 ppm. june 14, 2007 518 luminary micro confidential-advance product information electrical characteristics t clkper t r t clkhi t clklo t f
b. ieee 802.3 frequency tolerance 50 ppm. 22.2.8 hibernation module the hibernation module requires special system implementation considerations since it is intended to power-down all other sections of its host device. the system power-supply distribution and interfaces of the system must be driven to 0 v dc or powered down with the same regulator controlled by hib . the regulators controlled by hib are expected to have a settling time of 250 s or less. t able 22-22. hibernation module characteristics unit max nom min parameter name parameter parameter no s - 200 - internal 32.768 khz clock reference rising edge to /hib asserted t hib_low h1 s - 30 - internal 32.768 khz clock reference rising edge to /hib deasserted t hib_high h2 s - - 62 /w ake assertion time t w ake_asser t h3 s 124 - 62 /w ake assert to /hib desassert t w aket ohib h4 ms - - 20 xosc settling time a t xosc_settle h5 s - - 92 t ime for a write to non-volatile registers in hib module to complete t hib_reg_write h6 a. this parameter is highly sensitive to pcb layout and trace lengths, which may make this parameter time longer . care must be taken in pcb design to minimize trace lengths and rlc (resistance, inductance, capacitance). figure 22-4. hibernation module t iming 22.2.9 synchronous serial interface (ssi) t able 22-23. ssi characteristics unit max nom min parameter name parameter parameter no. system clocks 65024 - 2 ssiclk cycle time t clk_per s1 t clk_per - 1/2 - ssiclk high time t clk_high s2 t clk_per - 1/2 - ssiclk low time t clk_low s3 ns 26 7.4 - ssiclk rise/fall time t clkrf s4 ns 20 - 0 data from master valid delay time t dmd s5 ns - - 20 data from master setup time t dms s6 ns - - 40 data from master hold time t dmh s7 ns - - 20 data from slave setup time t dss s8 519 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller 32.768 khz ( internal) /hib h4 h1 /w ake h2 h3
unit max nom min parameter name parameter parameter no. ns - - 40 data from slave hold time t dsh s9 figure 22-5. ssi t iming for ti frame format (frf=01), single t ransfer t iming measurement figure 22-6. ssi t iming for microwire frame format (frf=10), single t ransfer june 14, 2007 520 luminary micro confidential-advance product information electrical characteristics ssiclk ssifss ssitx ssirx msb lsb s2 s3 s1 s4 4 to 16 bits 0 ssiclk ssifss ssitx ssirx msb lsb msb lsb s2 s3 s1 8-bit control 4 to 16 bits output data
figure 22-7. ssi t iming for spi frame format (frf=00), with sph=1 22.2.10 jt ag and boundary scan t able 22-24. jt ag characteristics unit max nom min parameter name parameter parameter no. mhz 10 - 0 tck operational clock frequency f tck j1 ns - - 100 tck operational clock period t tck j2 ns - t tck - tck clock low time t tck_low j3 ns - t tck - tck clock high time t tck_high j4 ns 10 - 0 tck rise time t tck_r j5 ns 10 - 0 tck fall time t tck_f j6 ns - - 20 tms setup time to tck rise t tms_su j7 ns - - 20 tms hold time from tck rise t tms_hld j8 ns - - 25 tdi setup time to tck rise t tdi_su j9 ns - - 25 tdi hold time from tck rise t tdi_hld j10 ns 35 23 - 2-ma drive tck fall to data v alid from high-z j1 1 t tdo_zdv ns 26 15 4-ma drive ns 25 14 8-ma drive ns 29 18 8-ma drive with slew rate control ns 35 21 - 2-ma drive tck fall to data v alid from data v alid j12 t tdo_dv ns 25 14 4-ma drive ns 24 13 8-ma drive ns 28 18 8-ma drive with slew rate control 521 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller ssiclk ( spo=1) ssitx ( master) ssirx ( slave) lsb ssiclk ( spo=0) s2 s1 s4 ssifss lsb s3 msb s5 s6 s7 s9 s8 msb
unit max nom min parameter name parameter parameter no. ns 1 1 9 - 2-ma drive tck fall to high-z from data v alid j13 t tdo_dvz ns 9 7 4-ma drive ns 8 6 8-ma drive ns 9 7 8-ma drive with slew rate control ns - - 100 trst assertion time t trst j14 ns - - 10 trst setup time to tck rise t trst_su j15 figure 22-8. jt ag t est clock input t iming figure 22-9. jt ag t est access port (t ap) t iming figure 22-10. jt ag trst t iming 22.2.1 1 general-purpose i/o note: all gpios are 5 v-tolerant. june 14, 2007 522 luminary micro confidential-advance product information electrical characteristics tdo output v alid tck tdo output v alid j12 tdo tdi tms tdi input v alid tdi input v alid j13 j9 j10 tms input v alid j9 j10 tms input v alid j1 1 j7 j8 j8 j7 tck j14 j15 trst tck j6 j5 j3 j4 j2
t able 22-25. gpio characteristics unit max nom min condition parameter name parameter ns 26 17 - 2-ma drive gpio rise t ime (from 20% to 80% of v dd ) t gpior ns 13 9 4-ma drive ns 9 6 8-ma drive ns 12 10 8-ma drive with slew rate control ns 25 17 - 2-ma drive gpio fall t ime (from 80% to 20% of v dd ) t gpiof ns 12 8 4-ma drive ns 10 6 8-ma drive ns 13 1 1 8-ma drive with slew rate control 22.2.12 reset t able 22-26. reset characteristics unit max nom min parameter name parameter parameter no. v - 2.0 - reset threshold v th r1 v 2.95 2.9 2.85 brown-out threshold v bth r2 ms - 10 - power-on reset timeout t por r3 s - 500 - brown-out timeout t bor r4 ms 1 1 - 6 internal reset timeout after por t irpor r5 s 1 - 0 internal reset timeout after bor a t irbor r6 ms 1 - 0 internal reset timeout after hardware reset ( rst pin) t irhwr r7 s 20 - 2.5 internal reset timeout after software-initiated system reset a t irswr r8 s 20 - 2.5 internal reset timeout after watchdog reset a t ir wdr r9 ms 100 - - supply voltage (v dd ) rise time (0v-3.3v) t vddrise r10 s - - 2 minimum rst pulse width t min r1 1 a. 20 * t mosc_per figure 22-1 1. external reset t iming ( rst ) 523 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller rst /reset ( internal) r7 r1 1
figure 22-12. power-on reset t iming figure 22-13. brown-out reset t iming figure 22-14. software reset t iming figure 22-15. w atchdog reset t iming june 14, 2007 524 luminary micro confidential-advance product information electrical characteristics r8 sw reset /reset ( internal) wdog reset ( internal) /reset ( internal) r9 vdd /bor ( internal) /reset ( internal) r2 r4 r6 vdd /por ( internal) /reset ( internal) r3 r1 r5
23 package information figure 23-1. 100-pin lqfp package notes 1. all dimensions shown in mm. 2. dimensions shown are nominal with tolerances indicated. 3. foot length 'l' is measured at gage plane 0.25 mm above seating plane. 4. l/f: eftec 64t cu or equivalent, 0.127 mm (0.005") or 0.152 mm (0.006") thick. 5. use variation bed for body dimensions. body +2.00 mm footprint, 1.4 mm package thickness 100l leads symbols 1.60 max. a 0.05 min./0.15 max. a 1 525 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
1.40 0.05 a 2 16.00 0.20 d 14.00 0.05 d 1 16.00 0.20 e 14.00 0.05 e 1 0.60 0.15/-0.10 l 0.50 basic e 0.22 0.05 b 0?~7? 0.08 max. ddd 0.08 max. ccc ms-026 jedec reference drawing bed v ariation designator june 14, 2007 526 luminary micro confidential-advance product information package information
24 ordering and contact information 24.1 ordering information t able 24-1. part ordering information description orderable part number stellaris ? lm3s8938 microcontroller lm3s8938-iqc50 24.2 company information luminary micro, inc. designs, markets, and sells arm cortex-m3-based microcontrollers (mcus). austin, t exas-based luminary micro is the lead partner for the cortex-m3 processor , delivering the world's first silicon implementation of the cortex-m3 processor . luminary micro's introduction of the stellaris? family of products provides 32-bit performance for the same price as current 8- and 16-bit microcontroller designs. with entry-level pricing at $1.00 for an arm technology-based mcu, luminary micro's stellaris product line allows for standardization that eliminates future architectural upgrades or software tool changes. luminary micro, inc. 108 wild basin, suite 350 austin, tx 78746 main: +1-512-279-8800 fax: +1-512-279-8879 http://www .luminarymicro.com sales@luminarymicro.com 24.3 support information for support on luminary micro products, contact: support@luminarymicro.com +1-512-279-8800, ext. 3 527 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller l m 3 s n n n n C g p p s s C r r m part number t emperature package speed revision shipping medium i = -40 c to 85 c t = t ape-and-reel omitted = default shipping (tray or tube) omitted = default to current shipping revision a 0 = first all-layer mask a 1 = metal layers update to a0 a 2 = metal layers update to a1 b 0 = second all-layer mask revision rn = 28-pin soic qn = 48-pin lqfp qc = 100-pin lqfp 20 = 20 mhz 25 = 25 mhz 50 = 50 mhz
a serial flash loader a.1 serial flash loader the stellaris ? serial flash loader is a preprogrammed flash-resident utility used to download code to the flash memory of a device without the use of a debug interface. the serial flash loader uses a simple packet interface to provide synchronous communication with the device. the flash loader runs of f the crystal and does not enable the pll, so its speed is determined by the crystal used. the two serial interfaces that can be used are the uar t0 and ssi interfaces. for simplicity , both the data format and communication protocol are identical for both serial interfaces. a.2 interfaces once communication with the flash loader is established via one of the serial interfaces, that interface is used until the flash loader is reset or new code takes over . for example, once you start communicating using the ssi port, communications with the flash loader via the uar t are disabled until the device is reset. a.2.1 uart the universal asynchronous receivers/t ransmitters (uar t) communication uses a fixed serial format of 8 bits of data, no parity , and 1 stop bit. the baud rate used for communication is automatically detected by the flash loader and can be any valid baud rate supported by the host and the device. the auto detection sequence requires that the baud rate should be no more than 1/32 the crystal frequency of the board that is running the serial flash loader . this is actually the same as the hardware limitation for the maximum baud rate for any uar t on a stellaris ? device. in order to determine the baud rate, the serial flash loader needs to determine the relationship between its own crystal frequency and the baud rate. this is enough information for the flash loader to configure its uar t to the same baud rate as the host. this automatic baud-rate detection allows the host to use any valid baud rate that it wants to communicate with the device. the method used to perform this automatic synchronization relies on the host sending the flash loader two bytes that are both 0x55. this generates a series of pulses to the flash loader that it can use to calculate the ratios needed to program the uar t to match the host s baud rate. after the host sends the pattern, it attempts to read back one byte of data from the uar t . the flash loader returns the value of 0xcc to indicate successful detection of the baud rate. if this byte is not received after at least twice the time required to transfer the two bytes, the host can resend another pattern of 0x55, 0x55, and wait for the 0xcc byte again until the flash loader acknowledges that it has received a synchronization pattern correctly . for example, the time to wait for data back from the flash loader should be calculated as at least 2*(20(bits/sync)/baud rate (bits/sec)). for a baud rate of 1 15200, this time is 2*(20/1 15200) or 0.35 ms. a.2.2 ssi the synchronous serial interface (ssi) port also uses a fixed serial format for communications, with the framing defined as motorola format with sph set to 1 and spo set to 1. see the section on ssi formats for more details on this transfer protocol. like the uar t , this interface has hardware requirements that limit the maximum speed that the ssi clock can run. this allows the ssi clock to be at most 1/12 the crystal frequency of the board running the flash loader . since the host device is the master , the ssi on the flash loader device does not need to determine the clock as it is provided directly by the host. june 14, 2007 528 luminary micro confidential-advance product information serial flash loader
a.3 packet handling all communications, with the exception of the uar t auto-baud, are done via defined packets that are acknowledged (ack) or not acknowledged (nak) by the devices. the packets use the same format for receiving and sending packets, including the method used to acknowledge successful or unsuccessful reception of a packet. a.3.1 packet format all packets sent and received from the device use the following byte-packed format. struct { unsigned char ucsize; unsigned char ucchecksum; unsigned char data[]; }; ucsize the first byte received holds the total size of the transfer including the size and checksum bytes. ucchecksum this holds a simple checksum of the bytes in the data buf fer only . the algorithm is data[0]+data[1]++ data[ ucsize -3]. data this is the raw data intended for the device, which is formatted in some form of command interface. there should be ucsize C2 bytes of data provided in this buf fer to or from the device. a.3.2 sending packets the actual bytes of the packet can be sent individually or all at once; the only limitation is that commands that cause flash memory access should limit the download sizes to prevent losing bytes during flash programming. this limitation is discussed further in the commands that interact with the flash. once the packet has been formatted correctly by the host, it should be sent out over the uar t or ssi interface. then the host should poll the uar t or ssi interface for the first non-zero data returned from the device. the first non-zero byte will either be an ack (0xcc) or a nak (0x33) byte from the device indicating the packet was received successfully (ack) or unsuccessfully (nak). this does not indicate that the actual contents of the command issued in the data portion of the packet were valid, just that the packet was received correctly . a.3.3 receiving packets the flash loader sends a packet of data in the same format that it receives a packet. the flash loader may transfer leading zero data before the first actual byte of data is sent out. the first non-zero byte is the size of the packet followed by a checksum byte, and finally followed by the data itself. there is no break in the data after the first non-zero byte is sent from the flash loader . once the device communicating with the flash loader receives all the bytes, it must either ack or nak the packet to indicate that the transmission was successful. the appropriate response after sending a nak to the flash loader is to resend the command that failed and request the data again. if needed, the host may send leading zeros before sending down the ack/nak signal to the flash loader , as the flash loader only accepts the first non-zero data as a valid response. this zero padding is needed by the ssi interface in order to receive data to or from the flash loader . 529 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
a.4 commands the next section defines the list of commands that can be sent to the flash loader . the first byte of the data should always be one of the defined commands, followed by data or parameters as determined by the command that is sent. a.4.1 command_ping (0x20) this command simply accepts the command and sets the global status to success. the format of the packet is as follows: byte[0] = 0x03; byte[1] = checksum(byte[2]); byte[2] = command_ping; the ping command has 3 bytes and the value for command_ping is 0x20 and the checksum of one byte is that same byte, making byte[1] also 0x20. since the ping command has no real return status, the receipt of an ack can be interpreted as a successful ping to the flash loader . a.4.2 command_get_st a tus (0x23) this command returns the status of the last command that was issued. t ypically , this command should be sent after every command to ensure that the previous command was successful or to properly respond to a failure. the command requires one byte in the data of the packet and should be followed by reading a packet with one byte of data that contains a status code. the last step is to ack or nak the received data so the flash loader knows that the data has been read. byte[0] = 0x03 byte[1] = checksum(byte[2]) byte[2] = command_get_status a.4.3 command_download (0x21) this command is sent to the flash loader to indicate where to store data and how many bytes will be sent by the command_send_data commands that follow . the command consists of two 32-bit values that are both transferred msb first. the first 32-bit value is the address to start programming data into, while the second is the 32-bit size of the data that will be sent. this command also triggers an erase of the full area to be programmed so this command takes longer than other commands. this results in a longer time to receive the ack/nak back from the board. this command should be followed by a command_get_status to ensure that the program address and program size are valid for the device running the flash loader . the format of the packet to send this command is a follows: byte[0] = 11 byte[1] = checksum(bytes[2:10]) byte[2] = command_download byte[3] = program address [31:24] byte[4] = program address [23:16] byte[5] = program address [15:8] byte[6] = program address [7:0] byte[7] = program size [31:24] byte[8] = program size [23:16] byte[9] = program size [15:8] byte[10] = program size [7:0] june 14, 2007 530 luminary micro confidential-advance product information serial flash loader
a.4.4 command_send_da t a (0x24) this command should only follow a command_download command or another command_send_data command if more data is needed. consecutive send data commands automatically increment address and continue programming from the previous location. the caller should limit transfers of data to a maximum 8 bytes of packet data to allow the flash to program successfully and not overflow input buf fers of the serial interfaces. the command terminates programming once the number of bytes indicated by the command_download command has been received. each time this function is called it should be followed by a command_get_status to ensure that the data was successfully programmed into the flash. if the flash loader sends a nak to this command, the flash loader does not increment the current address to allow retransmission of the previous data. byte[0] = 11 byte[1] = checksum(bytes[2:10]) byte[2] = command_send_data byte[3] = data[0] byte[4] = data[1] byte[5] = data[2] byte[6] = data[3] byte[7] = data[4] byte[8] = data[5] byte[9] = data[6] byte[10] = data[7] a.4.5 command_run (0x22) this command is used to tell the flash loader to execute from the address passed as the parameter in this command. this command consists of a single 32-bit value that is interpreted as the address to execute. the 32-bit value is transmitted msb first and the flash loader responds with an ack signal back to the host device before actually executing the code at the given address. this allows the host to know that the command was received successfully and the code is now running. byte[0] = 7 byte[1] = checksum(bytes[2:6]) byte[2] = command_run byte[3] = execute address[31:24] byte[4] = execute address[23:16] byte[5] = execute address[15:8] byte[6] = execute address[7:0] a.4.6 command_reset (0x25) this command is used to tell the flash loader device to reset. this is useful when downloading a new image that overwrote the flash loader and wants to start from a full reset. unlike the command_run command, this allows the initial stack pointer to be read by the hardware and set up for the new code. it can also be used to reset the flash loader if a critical error occurs and the host device wants to restart communication with the flash loader . byte[0] = 3 byte[1] = checksum(byte[2]) byte[2] = command_reset 531 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
the flash loader responds with an ack signal back to the host device before actually executing the software reset to the device running the flash loader . this allows the host to know that the command was received successfully and the part will be reset. june 14, 2007 532 luminary micro confidential-advance product information serial flash loader
b register quick reference 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 system control base: 0x400f .e000 class ver 0x000 did0 ro minor major 0x030 pborctl r/w borior 0x034 ldopctl r/w v adj 0x050 ris ro borris plllris 0x054 imc r/w borim plllim 0x058 misc r/w1c bormis plllmis 0x05c resc r/w ext por bor wdt sw ldo usesysdiv sysdiv acg 0x060 rcc r/w moscdis ioscdis oscsrc xt al byp ass pwrdn 0x064 pllcfg ro r f od sysdiv2 usercc2 0x070 rcc2 r/w oscsrc2 byp ass2 pwrdn2 dsdivoride 0x144 dslpclkcfg r/w dsoscsrc p ar tno f am ver 0x004 did1 ro qual rohs pkg temp pincount sramsz 0x008 dc0 ro flashsz saradc0 can0 0x010 dc1 ro jt ag swd swo wdt pll tempsns hib mpu maxadcspd sysdiv timer0 timer1 timer2 timer3 comp0 comp1 comp2 0x014 dc2 ro uar t0 uar t1 uar t2 ssi0 i2c0 i2c1 adc0 adc1 adc2 adc3 adc4 adc5 adc6 adc7 ccp0 ccp1 ccp2 ccp3 ccp4 ccp5 0x018 dc3 ro c0minus c0plus c0o c1minus c1plus c1o c2minus c2plus c2o e1588 emac0 ephy0 0x01c dc4 533 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ro gpioa gpiob gpioc gpiod gpioe gpiof gpiog saradc0 can0 0x100 rcgc0 r/w wdt hib maxadcspd saradc0 can0 0x1 10 scgc0 r/w wdt hib maxadcspd saradc0 can0 0x120 dcgc0 r/w wdt hib maxadcspd timer0 timer1 timer2 timer3 comp0 comp1 comp2 0x104 rcgc1 r/w uar t0 uar t1 uar t2 ssi0 i2c0 i2c1 timer0 timer1 timer2 timer3 comp0 comp1 comp2 0x1 14 scgc1 r/w uar t0 uar t1 uar t2 ssi0 i2c0 i2c1 timer0 timer1 timer2 timer3 comp0 comp1 comp2 0x124 dcgc1 r/w uar t0 uar t1 uar t2 ssi0 i2c0 i2c1 emac0 ephy0 0x108 rcgc2 r/w gpioa gpiob gpioc gpiod gpioe gpiof gpiog emac0 ephy0 0x1 18 scgc2 r/w gpioa gpiob gpioc gpiod gpioe gpiof gpiog emac0 ephy0 0x128 dcgc2 r/w gpioa gpiob gpioc gpiod gpioe gpiof gpiog saradc0 can0 0x040 srcr0 r/w wdt hib timer0 timer1 timer2 timer3 comp0 comp1 comp2 0x044 srcr1 r/w uar t0 uar t1 uar t2 ssi0 i2c0 i2c1 emac0 ephy0 0x048 srcr2 r/w gpioa gpiob gpioc gpiod gpioe gpiof gpiog hibernation module r tcc 0x000 hibrtcc ro r tcc r tcm0 0x004 hibrtcm0 r/w r tcm0 r tcm1 0x008 hibrtcm1 r/w r tcm1 r tcld 0x00c hibrtcld r/w r tcld 0x010 hibctl r/w r tcen hibreq clksel r tcwen pinwen lowba ten clk32en v abor t 0x014 hibim june 14, 2007 534 luminary micro confidential-advance product information register quick reference
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r/w r tcal t0 r tcal t1 lowba t extw 0x018 hibris ro r tcal t0 r tcal t1 lowba t extw 0x01c hibmis ro r tcal t0 r tcal t1 lowba t extw 0x020 hibic w1c r tcal t0 r tcal t1 lowba t extw 0x024 hibrtct r/w trim r td 0x030- 0x12c hibda t a r/w r td internal memory base: 0x400f .d000 base: 0x400f .e000 offset 0x000 fma r/w offset da t a 0x004 fmd r/w da t a wrkey 0x008 fmc r/w write erase merase comt 0x00c fcris ro aris pris 0x010 fcim r/w amask pmask 0x014 fcmisc r/w1c amisc pmisc 0x140 usecrl r/w usec read_enable 0x130 and 0x200 fmpre0 r/w read_enable prog_enable 0x134 and 0x400 fmppe0 r/w prog_enable da t a notwritten 0x1d0 user_dbg r/w dbg0 dbg1 init1 da t a da t a notwritten 0x1e0 user_reg0 r/w da t a 535 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 da t a notwritten 0x1e4 user_reg1 r/w da t a read_enable 0x204 fmpre1 r/w read_enable read_enable 0x208 fmpre2 r/w read_enable read_enable 0x20c fmpre3 r/w read_enable prog_enable 0x404 fmppe1 r/w prog_enable prog_enable 0x408 fmppe2 r/w prog_enable prog_enable 0x40c fmppe3 r/w prog_enable general-purpose input/outputs (gpios) base: 0x4000.4000 base: 0x4000.5000 base: 0x4000.6000 base: 0x4000.7000 base: 0x4002.4000 base: 0x4002.5000 base: 0x4002.6000 0x000 gpioda t a r/w da t a 0x400 gpiodir r/w dir 0x404 gpiois r/w is 0x408 gpioibe r/w ibe 0x40c gpioiev r/w iev 0x410 gpioim r/w ime 0x414 gpioris ro ris 0x418 gpiomis ro mis 0x41c gpioicr june 14, 2007 536 luminary micro confidential-advance product information register quick reference
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 w1c ic 0x420 gpioafsel r/w afsel 0x500 gpiodr2r r/w dr v2 0x504 gpiodr4r r/w dr v4 0x508 gpiodr8r r/w dr v8 0x50c gpioodr r/w ode 0x510 gpiopur r/w pue 0x514 gpiopdr r/w pde 0x518 gpioslr r/w srl 0x51c gpioden r/w den lock 0x520 gpiolock r/w lock 0x524 gpiocr - cr 0xfd0 gpioperiphid4 ro pid4 0xfd4 gpioperiphid5 ro pid5 0xfd8 gpioperiphid6 ro pid6 0xfdc gpioperiphid7 ro pid7 0xfe0 gpioperiphid0 ro pid0 0xfe4 gpioperiphid1 ro pid1 0xfe8 gpioperiphid2 ro pid2 537 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 0xfec gpioperiphid3 ro pid3 0xff0 gpiopcellid0 ro cid0 0xff4 gpiopcellid1 ro cid1 0xff8 gpiopcellid2 ro cid2 0xffc gpiopcellid3 ro cid3 general-purpose t imers base: 0x4003.0000 base: 0x4003.1000 base: 0x4003.2000 base: 0x4003.3000 0x000 gptmcfg r/w gptmcfg 0x004 gptmt amr r/w t amr t acmr t aams 0x008 gptmtbmr r/w tbmr tbcmr tbams 0x00c gptmctl r/w t aen t ast all t aevent r tcen t aote t apwml tben tbst all tbevent tbote tbpwml 0x018 gptmimr r/w t a t oim camim caeim r tcim tbt oim cbmim cbeim 0x01c gptmris ro t a t oris camris caeris r tcris tbt oris cbmris cberis 0x020 gptmmis ro t a t omis cammis caemis r tcmis tbt omis cbmmis cbemis 0x024 gptmicr w1c t a t ocint camcint caecint r tccint tbt ocint cbmcint cbecint t ailrh 0x028 gptmt ailr r/w t ailrl 0x02c gptmtbilr r/w tbilrl t amrh 0x030 gptmt ama tchr r/w t amrl 0x034 gptmtbma tchr june 14, 2007 538 luminary micro confidential-advance product information register quick reference
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r/w tbmrl 0x038 gptmt apr r/w t apsr 0x03c gptmtbpr r/w tbpsr 0x040 gptmt apmr r/w t apsmr 0x044 gptmtbpmr r/w tbpsmr t arh 0x048 gptmt ar ro t arl 0x04c gptmtbr ro tbrl w atchdog t imer base: 0x4000.0000 wdtload 0x000 wdtload r/w wdtload wdtv alue 0x004 wdtv alue ro wdtv alue 0x008 wdtctl r/w inten resen wdtintclr 0x00c wdticr wo wdtintclr 0x010 wdtris ro wdtris 0x014 wdtmis ro wdtmis 0x418 wdttest r/w st all wdtlock 0xc00 wdtlock r/w wdtlock 0xfd0 wdtperiphid4 ro pid4 0xfd4 wdtperiphid5 ro pid5 0xfd8 wdtperiphid6 ro pid6 539 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 0xfdc wdtperiphid7 ro pid7 0xfe0 wdtperiphid0 ro pid0 0xfe4 wdtperiphid1 ro pid1 0xfe8 wdtperiphid2 ro pid2 0xfec wdtperiphid3 ro pid3 0xff0 wdtpcellid0 ro cid0 0xff4 wdtpcellid1 ro cid1 0xff8 wdtpcellid2 ro cid2 0xffc wdtpcellid3 ro cid3 analog-to-digital converter (adc) base: 0x4003.8000 0x000 adcactss r/w asen0 asen1 asen2 asen3 0x004 adcris ro inr0 inr1 inr2 inr3 0x008 adcim r/w mask0 mask1 mask2 mask3 0x00c adcisc r/w1c in0 in1 in2 in3 0x010 adcost a t r/w1c ov0 ov1 ov2 ov3 0x014 adcemux r/w em0 em1 em2 em3 0x018 adcust a t r/w1c uv0 uv1 uv2 uv3 0x020 adcsspri r/w ss0 ss1 ss2 ss3 0x028 adcpssi june 14, 2007 540 luminary micro confidential-advance product information register quick reference
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 wo ss0 ss1 ss2 ss3 0x030 adcsac r/w a vg mux4 mux5 mux6 mux7 0x040 adcssmux0 r/w mux0 mux1 mux2 mux3 d4 end4 ie4 ts4 d5 end5 ie5 ts5 d6 end6 ie6 ts6 d7 end7 ie7 ts7 0x044 adcssctl0 r/w d0 end0 ie0 ts0 d1 end1 ie1 ts1 d2 end2 ie2 ts2 d3 end3 ie3 ts3 0x048 adcssfifo0 ro da t a 0x068 adcssfifo1 ro da t a 0x088 adcssfifo2 ro da t a 0x04c adcssfst a t0 ro tptr hptr empty full 0x06c adcssfst a t1 ro tptr hptr empty full 0x08c adcssfst a t2 ro tptr hptr empty full 0x060 adcssmux1 r/w mux0 mux1 mux2 mux3 0x064 adcssctl1 r/w d0 end0 ie0 ts0 d1 end1 ie1 ts1 d2 end2 ie2 ts2 d3 end3 ie3 ts3 0x080 adcssmux2 r/w mux0 mux1 mux2 mux3 0x084 adcssctl2 r/w d0 end0 ie0 ts0 d1 end1 ie1 ts1 d2 end2 ie2 ts2 d3 end3 ie3 ts3 0x0a0 adcssmux3 r/w mux0 0x0a4 adcssctl3 r/w d0 end0 ie0 ts0 0x0a8 adcssfifo3 ro 0x0ac adcssfst a t3 ro 0x100 adctmlb r/w mux ts diff cont cnt 541 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 0x100 adctmlb r/w lb universal asynchronous receivers/t ransmitters (uart s) base: 0x4000.c000 base: 0x4000.d000 base: 0x4000.e000 0x000 uartdr ro da t a fe pe be oe 0x004 uartrsr/ uartecr r/w fe pe be oe 0x004 uartrsr/ uartecr r/w da t a 0x018 uartfr ro busy rxfe txff rxff txfe 0x020 uartilpr r/w ilpdvsr 0x024 uartibrd r/w divint 0x028 uartfbrd r/w divfrac 0x02c uartlcrh r/w brk pen eps stp2 fen wlen sps 0x030 uartctl r/w uar ten siren sirlp lbe txe rxe 0x034 uartifls r/w txiflsel rxiflsel 0x038 uartim r/w rxim txim r tim feim peim beim oeim 0x03c uartris ro rxris txris r tris feris peris beris oeris 0x040 uartmis ro rxmis txmis r tmis femis pemis bemis oemis 0x044 uarticr w1c rxic txic r tic feic peic beic oeic 0xfd0 uartperiphid4 ro pid4 0xfd4 uartperiphid5 june 14, 2007 542 luminary micro confidential-advance product information register quick reference
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ro pid5 0xfd8 uartperiphid6 ro pid6 0xfdc uartperiphid7 ro pid7 0xfe0 uartperiphid0 ro pid0 0xfe4 uartperiphid1 ro pid1 0xfe8 uartperiphid2 ro pid2 0xfec uartperiphid3 ro pid3 0xff0 uartpcellid0 ro cid0 0xff4 uartpcellid1 ro cid1 0xff8 uartpcellid2 ro cid2 0xffc uartpcellid3 ro cid3 synchronous serial interface (ssi) base: 0x4000.8000 0x000 ssicr0 r/w dss frf spo sph scr 0x004 ssicr1 r/w lbm sse ms sod 0x008 ssidr r/w da t a 0x00c ssisr ro tfe tnf rne rff bsy 0x010 ssicpsr r/w cpsdvsr 0x014 ssiim r/w rorim r tim rxim txim 0x018 ssiris ro rorris r tris rxris txris 543 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 0x01c ssimis ro rormis r tmis rxmis txmis 0x020 ssiicr w1c roric r tic 0xfd0 ssiperiphid4 ro pid4 0xfd4 ssiperiphid5 ro pid5 0xfd8 ssiperiphid6 ro pid6 0xfdc ssiperiphid7 ro pid7 0xfe0 ssiperiphid0 ro pid0 0xfe4 ssiperiphid1 ro pid1 0xfe8 ssiperiphid2 ro pid2 0xfec ssiperiphid3 ro pid3 0xff0 ssipcellid0 ro cid0 0xff4 ssipcellid1 ro cid1 0xff8 ssipcellid2 ro cid2 0xffc ssipcellid3 ro cid3 inter-integrated circuit (i 2 c) interface base: 0x4002.0000 base: 0x4002.0800 base: 0x4002.1000 base: 0x4001.1800 0x000 i2cmsa r/w r/s sa 0x004 i2cmcs r/w busy error adrack da t ack arblst idle busbsy 0x004 i2cmcs june 14, 2007 544 luminary micro confidential-advance product information register quick reference
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r/w run st ar t st op ack 0x008 i2cmdr r/w da t a 0x00c i2cmtpr r/w tpr 0x010 i2cmimr r/w im 0x014 i2cmris ro ris 0x018 i2cmmis ro mis 0x01c i2cmicr wo ic 0x020 i2cmcr r/w lpbk mfe sfe 0x000 i2csoar r/w oar 0x004 i2cscsr ro rreq treq fbr 0x004 i2cscsr ro da 0x008 i2csdr r/w da t a 0x00c i2csimr r/w im 0x010 i2csris ro ris 0x014 i2csmis ro mis 0x018 i2csicr wo ic controller area network (can) module base: 0x4004.0000 0x000 canctl r/w init ie sie eie dar cce t est 0x004 cansts r/w lec txok rxok epass ew arn bof f 545 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 0x008 canerr ro tec rec rp 0x00c canbit r/w brp sjw tseg1 tseg2 0x010 canint ro intid 0x014 cantst r/w basic silent lback tx rx 0x018 canbrpe r/w brpe 0x020 canif1crq r/w mnum busy 0x080 canif2crq r/w mnum busy 0x024 canif1cmsk r/w datab dataa txrqst/newdat clrintpnd control arb mask wrnrd 0x084 canif2cmsk r/w datab dataa txrqst/newdat clrintpnd control arb mask wrnrd 0x028 canif1msk1 r/w msk 0x088 canif2msk1 r/w msk 0x02c canif1msk2 r/w msk mdir mxtd 0x08c canif2msk2 r/w msk mdir mxtd 0x030 canif1arb1 r/w id 0x090 canif2arb1 r/w id 0x034 canif1arb2 r/w id dir xtd msgv al 0x094 canif2arb2 r/w id dir xtd msgv al 0x038 canif1mctl r/w dlc eob txrqst rmten rxie txie umask intpnd msglst newdat 0x098 canif2mctl june 14, 2007 546 luminary micro confidential-advance product information register quick reference
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 r/w dlc eob txrqst rmten rxie txie umask intpnd msglst newdat 0x03c canif1da1 r/w data 0x09c canif2da1 r/w data 0x040 canif1da2 r/w data 0x0a0 canif2da2 r/w data 0x044 canif1db1 r/w data 0x0a4 canif2db1 r/w data 0x048 canif1db2 r/w data 0x0a8 canif2db2 r/w data 0x100 cantxrq1 ro txrqst 0x104 cantxrq2 ro txrqst 0x120 cannwda1 ro newdat 0x124 cannwda2 ro newdat 0x140 canmsg1int ro intpnd 0x144 canmsg2int ro intpnd 0x160 canmsg1v al ro msgv al 0x164 canmsg2v al ro msgv al ethernet controller base: 0x4004.8000 0x000 macris ro rxint txer txemp fov rxer mdint phyint 547 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 0x000 maciack w1c rxint txer txemp fov rxer mdint 0x004 macim r/w rxintm txerm txempm fovm rxerm mdintm phyintm 0x008 macrctl r/w rxen amul prms badcrc rstfifo 0x00c mactctl r/w txen p aden crc duplex rxda t a 0x010 macda t a r/w rxda t a txda t a 0x010 macda t a r/w txda t a macoct3 macoct4 0x014 macia0 r/w macoct1 macoct2 0x018 macia1 r/w macoct5 macoct6 0x01c macthr r/w thresh 0x020 macmctl r/w st ar t write regadr 0x024 macmdv r/w div 0x028 macmadd ro 0x02c macmtxd r/w mdtx 0x030 macmrxd r/w mdrx 0x034 macnp ro npr 0x038 mactr r/w newtx 0x00 mr0 r/w col t duplex raneg iso pwrdn anegen speedsl loopbk reset 0x01 mr1 ro extd jab link anega rf aul t anegc mfps 10t_h 10t_f 100x_h 100x_f 0x02 mr2 june 14, 2007 548 luminary micro confidential-advance product information register quick reference
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 ro oui[21:6] 0x03 mr3 ro rn mn oui[5:0] 0x04 mr4 r/w s[4:0] a0 a1 a2 a3 rf np 0x05 mr5 ro s[4:0] a[7:0] rf ack np 0x06 mr6 ro lp anega prx lpnp a pdf 0x10 mr16 r/w rxcc pcsbp r vspol apol nl10 sqei txhim inpol rptr 0x1 1 mr17 r/w anegcomp_int rf aul t_int lschg_int lp ack_int pdf_int prx_int rxer_int jabber_int anegcomp_ie rf aul t_ie lschg_ie lp ack_ie pdf_ie prx_ie rxer_ie jabber_ie 0x12 mr18 ro rx_lock rxsd ra te dplx anegf 0x13 mr19 r/w txo[1:0] 0x17 mr23 r/w led0[3:0] led1[3:0] 0x18 mr24 r/w mdix_sd mdix_cm mdix aut o_sw pd_mode analog comparators base: 0x4003.c000 0x00 acmis r/w1c in0 in1 in2 0x04 acris ro in0 in1 in2 0x08 acinten r/w in0 in1 in2 0x10 acrefctl r/w vref rng en 0x20 acst a t0 ro ov al 0x40 acst a t1 ro ov al 0x60 acst a t2 ro ov al 549 june 14, 2007 luminary micro confidential-advance product information lm3s8938 microcontroller
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 offset name 0 1 2 3 4 5 6 7 8 9 10 1 1 12 13 14 15 0x24 acctl0 r/w cinv isen isl v al tsen tsl v al asrcp t oen 0x44 acctl1 r/w cinv isen isl v al tsen tsl v al asrcp t oen 0x64 acctl2 r/w cinv isen isl v al tsen tsl v al asrcp t oen june 14, 2007 550 luminary micro confidential-advance product information register quick reference

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