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rev. c information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. no license is granted by implication or otherwise under any patent or patent rights of analog devices. a admc326 one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781/329-4700 www.analog.com fax: 781/326-8703 ? analog devices, inc., 2001 28-lead rom-based dsp motor controller functional block diagram serial port sport1 9-bit pio 2 8-bit aux pwm watch- dog timer program rom 4k 24 arithmetic units shifter mac alu adsp-2100 base architecture program sequencer data address generators dag 1 dag 2 memory block program ram 512 24 timer 6 analog inputs 16-bit 3-phase pwm program memory address data memory address data memory data program memory data por data memory 512 16 vref target applications washing machines, refrigerator compressors, fans, pumps, industrial variable speed drives, automotive motor types ac induction motors permanent magnet synchronous motors (pmsm) brushless dc motors (bdcm) features 20 mips fixed-point dsp core single cycle instruction execution (50 ns) adsp-21xx family code compatible independent computational units alu multiplier/accumulator barrel shifter multifunction instructions single cycle context switch powerful program sequencer zero overhead looping conditional instruction execution two independent data address generators memory configuration 512 24-bit program memory ram 4k 24-bit program memory rom 512 16-bit data memory ram three-phase 16-bit pwm generator 16-bit center-based pwm generator programmable dead time and narrow pulse deletion edge resolution to 50 ns 150 hz minimum switching frequency double/single duty cycle update mode control programmable pwm pulsewidth special crossover function for brushless dc motors individual enable and disable for each pwm output high frequency chopping mode for transformer coupled gate drives external pwmtrip pin integrated adc subsystem six analog inputs acquisition synchronized to pwm switching frequency internal voltage reference 9-pin digital i/o port bit configurable as input or output change of state interrupt support two 8-bit auxiliary pwm timers synthesized analog output programmable frequency 0% to 100% duty cycle two programmable operational modes independent mode/offset mode 16-bit watchdog timer programmable 16-bit internal timer with prescaler double buffered synchronous serial port hardware support for uart emulation integrated power-on reset function 28-lead soic or pdip package options
C2C rev. c admc326?pecifications (v dd = 5 v 5%, gnd = 0 v, t a = ?0 c to +105 c for admc326y, t a = ?0 c to +125 c for admc326t, clkin = 10 mhz, unless otherwise noted.) analog-to-digital converter parameter min typ max unit conditions/comments signal input 0.3 3.5 v v1, v2, v3, vaux0, vaux1, vaux2 resolution 1 12 bits linearity error 2 2 4 bits zero offset 2 ?0 0 +20 mv channel-to-channel comparator match 2 20 mv comparator delay 600 ns adc hi-level input current 2 +10 av in = 3.5 v adc lo-level input current 2 ?0 av in = 0.0 v notes 1 resolution varies with pwm switching frequency (double update mode) 78.1 khz = 8 bits, 4.9 khz = 12 bits. 2 2.44 khz sample frequency, v1, v2, vaux0, vaux1, vaux2. specifications subject to change without notice. electrical characteristics parameter min typ max unit conditions/comments v il lo-level input voltage 0.8 v v ih hi-level input voltage 2 v v ol low level output voltage 1 0.4 v i ol = 2 ma v ol low level output voltage 2 0.8 v i ol = 2 ma v oh high level output voltage 4 v i oh = ?.5 ma i il low level input current 3 ?20 av in = 0 v i il low level input current ?0 av in = 0 v i ih high level input current 4 90 av in = v dd i ih high level input current 10 av in = v dd i ozh hi-level three-state leakage current 5 90 av in = v dd i ozl lo-level three-state leakage current 5 ?0 av in = 0 i il lo-level pwmtrip current ?0 a@ v dd = max, v in = 0 v i dd supply current (idle) 6 35 ma i dd supply current (dynamic) 6 60 ma notes 1 output pins pio0?io8, ah, al, bh, bl, ch, cl. 2 xtal pin. 3 internal pull-up, reset . 4 internal pull-down, pwmtrip , pio0?io8. 5 three-stateable pins dt1, rfs1, tfs1, sclk1. 6 outputs not switching. specifications subject to change without notice. current source 1 parameter min typ max unit conditions/comments programming resolution 3 bits default current 2 70 83 95 a iconst_trim = 0x00 tuned current 95 100 105 a notes 1 for adc calibration. 2 0.3 v to 3.5 v iconst voltage. specifications subject to change without notice.
C3C rev. c admc326 voltage reference parameter min typ max unit conditions/comments voltage level (v ref ) 2.40 2.50 2.60 v 2.45 2.50 2.55 v t a = 25 c to 125 c soic 1 output voltage drift 35 ppm/ c notes 1 this specification for voltage level (v ref ) is for soic package only, at specified temperature range. specifications subject to change without notice. power-on reset parameter min typ max unit conditions/comments reset threshold (v rst ) 3.2 3.7 4.2 v hysteresis (v hyst ) 100 mv reset active timeout period ( t rst ) 3.2 1 ms notes 1 2 16 clkout cycles. specifications subject to change without notice.
admc326 C4C rev. c timing parameters parameter min max unit clock signals signal t ck is defined as 0.5 t ckin . the admc326 uses an input clock with a frequency equal to half the instruction rate; a 10 mhz input clock (which is equivalent to 100 ns) yields a 50 ns processor cycle (equivalent to 20 mhz). when t ck values are within the range of 0.5 t ckin period, they should be substituted for all relevant timing parameters to obtain specification value. example: t ckh = 0.5 t ck ?10 ns = 0.5 (50 ns) ?10 ns = 15 ns. timing requirements: t ckin clkin period 100 150 ns t ckil clkin width low 20 ns t ckih clkin width high 20 ns switching characteristics: t ckl clkout width low 0.5 t ck ?10 ns t ckh clkout width high 0.5 t ck ?10 ns t ckoh clkin high to clkout high 0 20 ns control signals timing requirement: t rsp reset width low 5 t ck 1 ns pwm shutdown signals timing requirement: t pwmtpw pwmtrip width low t ck ns notes 1 applies after power-up sequence is complete. specifications subject to change without notice. clkin clkout t ckl t ckil t ckh t ckih t ckin t ckoh figure 1. clock signals
admc326 C5C rev. c parameter min max unit serial ports timing requirements: t sck sclk period 100 ns t scs dr/tfs/rfs setup before sclk low 15 ns t sch dr/tfs/rfs hold after sclk low 20 ns t scp sclk in width 40 ns switching characteristics : t cc clkout high to sclk out 0.25 t ck 0.25 t ck + 20 ns t scde sclk high to dt enable 0 ns t scdv sclk high to dt valid 30 ns t rh tfs/rfs out hold after sclk high 0 ns t rd tfs/rfs out delay from sclk high 30 ns t scdh dt hold after sclk high 0 ns t scdd sclk high to dt disable 30 ns t tde tfs (alt) to dt enable 0 ns t tdv tfs (alt) to dt valid 25 ns t rdv rfs (multichannel, frame delay zero) to dt valid 30 ns specifications subject to change without notice. t cc t cc t scs t rd t rh t scdv t scde t scdd t tdv t rdv clkout sclk dr rfs in tfs in rfs out tfs out dt tfs (alternate frame mode) rfs (multichannel mode, frame delay 0 [mfd = 0]) t scp t sck t scp t sch t scdh t tde figure 2. serial port timing
admc326 C6C rev. c caution esd (electrostatic discharge) sensitive device. electrostatic charges as high as 4000 v readily accumulate on the human body and test equipment and can discharge without detection. although the admc326 features proprietary esd protection circuitry, permanent damage may occur on devices subjected to high-energy electrostatic discharges. therefore, proper esd precautions are recommended to avoid performance degradation or loss of functionality. absolute maximum ratings * supply voltage (v dd ) . . . . . . . . . . . . . . . . . . ?.3 v to +7.0 v input voltage . . . . . . . . . . . . . . . . . . . . . ?.3 v to v dd + 0.3 v output voltage swing . . . . . . . . . . . . . . ?.3 v to v dd + 0.3 v operating temperature range (ambient) admc326y . . . . . . . . . . . . . . . . . . . . . . ?0 c to +105 c admc326t . . . . . . . . . . . . . . . . . . . . . . ?0 c to +125 c storage temperature range . . . . . . . . . . . . ?5 c to +150 c lead temperature (5 sec) . . . . . . . . . . . . . . . . . . . . . . . 280 c * stresses greater than those listed may cause permanent damage to the device. these are stress ratings only; functional operation of the device at these or any other conditions greater than those indicated in the operational sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. ordering guide temperature instruction package package model range rate (mhz) description option admc326yr-xxx-yy ?0 c to +105 c 20 28-lead wide body (soic) r-28 admc326tr-xxx-yy ?0 c to +125 c 20 28-lead wide body (soic) r-28 ADMC326YN-XXX-YY ?0 c to +105 c 20 28-lead wide body (pdip) n-28 admc326tn-xxx-yy ?0 c to +125 c 20 28-lead wide body (pdip) n-28 notes xxx = customer identification code. yy = rom identification code. to place an order for a custom rom-coded admc326 processor, please request a copy of the admc rom ordering package, available f rom your analog devices sales representative. analog devices assesses a charge for each rom mask generated in addition to a minimum order quantity. please consult your sales representative for details. pin function descriptions pin no. pin name pin type pa porta 1 pio6 / clkout i/o 2 pio5/rfs1 i/o 3 pio4/dr1a i/o 4 pio3/sclk1 i/o 5 pio2/dr1b i/o 6 pio1/dt1 i/o 7 pio0/tfs1 i/o 8 clkin i 9 xtal o 10 v dd sup 11 pwmtrip i 12 v3 i 13 v2 i 14 v1 i 15 vaux0 i 16 vaux1 i 17 vaux2 i 18 iconst o 19 gnd gnd 20 reset i 21 ch o 22 cl o 23 bh o 24 bl o 25 ah o 26 al o 27 pio8/aux0 i/o 28 pio7/aux1 i/o pin configuration 28 27 26 25 24 23 22 21 20 19 18 17 16 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 v1 v2 v3 v dd xtal clkin pio6/clkout pio5/rfs1 pio4/dr1a pio3/sclk1 pio0/tfs1 pio1/dt1 pio2/dr1b vaux0 vaux1 vaux2 iconst gnd reset ch pio7/aux1 pio8/aux0 al ah cl bh bl top view (not to scale) admc326 pwmtrip warning! esd sensitive device
admc326 C7C rev. c general description the admc326 is a low cost, single-chip dsp-based controller, suitable for permanent magnet synchronous motors, ac induction motors and brushless dc motors. the admc326 integrates a 20 mips, fixed-point dsp core with a complete set of motor control and system peripherals that permits fast, efficient development of m otor controllers. the dsp core of the admc326 is the adsp-2171, which is completely code compatible with the adsp-21xx dsp family and combines three computational units, data address genera tors and a program sequencer. the computational units comprise an alu, a multiplier/accumulator (mac) and a barrel shifter. the adsp-2171 adds new instructions for bit manipulation, multipli- cation ( squared), biased rounding and global interrupt masking. the system peripherals are the power-on reset circuit (por), the watchdog timer and a synchronous serial port. the serial port is configurable and double buffered, with hardware support for uart and sci port emulation. the admc326 provides 512 24-bit program memory ram, 4k 24-bit program memory rom and 512 16-bit data memory ram. the program memory rom contains the user- specified program code and is defined using a single metal layer mask. the program and data memory ram can be used for dynamic data storage. the motor control peripherals of the admc326 comprise a 12-bit analog data acquisition system with six analog input channels and an internal voltage reference. in addition, a three- phase, 16-bit, center-based pwm generation unit can be used to produce h igh accuracy pwm signals with minimal processor overhead. the admc326 also contains two auxiliary pwm outputs, and nine lines of digital i/o. because the admc326 has a limited number of pins, a number of functions such as the auxiliary pwm and the serial commu- nication port are multiplexed with the nine programmable input/ output (pio) pins. the pin functions can be independently selected to allow maximum flexibility for different applications. bus exchange companding circuitry data address generator #2 data address generator #1 14 14 24 16 6 r bus 16 dma bus pma bus dmd bus pmd bus instruction register input regs output regs shifter control logic dm ram 512 16 pm rom 4k 24 pm ram 512 24 serial port receive reg transmit reg timer input regs output regs mac input regs output regs alu program sequencer figure 3. dsp core block diagram
admc326 C8C rev. c dsp core architecture overview figure 3 is an overall block diagram of the dsp core of the admc326, w hich is based on the fixed-point adsp-2171. the flexible architecture and comprehensive instruction set of the adsp-2171 allow the processor to perform multiple operations in parallel. in one processor cycle (50 ns with a 10 mhz clkin) the dsp core can: ? generate the next program address. ? fetch the next instruction. ? perform one or two data moves. ? update one or two data address pointers. ? perform a computational operation. this all takes place while the processor continues to: ? receive and transmit through the serial port. ? decrement the interval timer. ? generate three-phase pwm waveforms for a power inverter. ? generate two signals using the 8-bit auxiliary pwm timers. ? acquire four analog signals. ? decrement the watchdog timer. the processor contains three independent computational units: the arithmetic and logic unit (alu), the multiplier/accumulator (mac) and the shifter. the computational units process 16-bit data directly and have provisions to support multiprecision com- putations. the alu performs a standard set of arithmetic and logic operations as well as providing support for division primi- tives. the mac performs single-cycle multiply, multiply/add, and multiply/subtract operations with 40 bits of accumulation. the shifter performs logical and arithmetic shifts, normalization, denormalization and derive-exponent operations. the shifter can be used to efficiently implement numeric format control, including floating-point representations. the internal result (r) bus directly connects the computational units so that the output of any unit may be the input of any unit on the next cycle. a powerful program sequencer and two dedicated data address generators ensure efficient delivery of operands to these compu- tational units. the sequencer supports conditional jumps and subroutine calls and returns in a single cycle. with internal loop counters and loop stacks, the admc326 executes looped code with zero overhead; no explicit jump instructions are required to maintain the loop. two data address generators (dags) provide addresses for simultaneous dual operand fetches from data memory and pro- gram memory. each dag maintains and updates four address pointers (i registers). whenever the pointer is used to access data (indirect addressing), it is post-modified by the value in one of four modify (m registers). a length value may be associ- ated with each pointer (l registers) to implement automatic modulo addressing for circular buffers. the circular buffering feature is also used by the serial ports for automatic data trans- fers to and from on-chip memory. dag1 generates only data memory address and provides an optional bit-reversal capability. dag2 may generate either program or data memory addresses but has no bit-reversal capability. efficient data transfer is achieved with the use of five internal buses: ? program memory address (pma) bus. ? program memory data (pmd) bus. ? data memory address (dma) bus. ? data memory data (dmd) bus. ? result (r) bus. program memory can store both instructions and data, permit- ting the admc326 to fetch two operands in a single cycle one from program memory and one from data memory. the admc326 can fetch an operand from on-chip program memory and the next instruction in the same cycle. the admc326 writes data from its 16-bit registers to the 24-bit program memory using the px register to provide the lower eight bits. when it reads data (not instructions) from 24-bit pro- gram memory to a 16-bit data register, the lower eight bits are placed in the px register. the admc326 can respond to a number of distinct dsp core and peripheral interrupts. the dsp interrupts comprise a serial port receive interrupt, a serial port transmit interrupt, a timer interrupt, and two software interrupts. additionally, the motor control peripherals include two pwm interrupts and a pio interrupt. the serial port (sport1) provides a complete synchronous serial interface with optional companding in hardware and a wide variety of framed and unframed data transmit and receive modes of operation. sport1 can generate an internal program- mable serial clock or accept an external serial clock. a programmable interval counter is also included in the dsp core and can be used to generate periodic interrupts. a 16-bit count register (tcount) is decremented every n processor cycles, where n? is a scaling value stored in the 8-bit tscale register. when the value of the counter reaches zero, an interrupt is generated, and the count register is reloaded from a 16-bit period register (tperiod). the admc326 instruction set provides flexible data moves and multifunction (one or two data moves with a c omputation) instructions. each instruction is executed in a single 50 ns pro- cessor cycle (for a 10 mhz clkin). the a dmc326 assembly language uses an algebraic syntax for ease of coding and read ability. a comprehensive set of development tools supports program development. for further information on the dsp core, refer to the adsp-2100 family user? manual, third edition, with par- ticular reference to the adsp-2171. serial port the admc326 incorporates a complete synchronous serial port (sport1) for serial communication and multiprocessor communication. the following is a brief list of capabilities of the admc326 sport1. refer to the adsp-2100 family user? manual , third edition, for further details. ? sport1 is bidirectional and has a separate, double-buffered transmit and receive section. ? sport1 can use an external serial clock or generate its own serial clock internally. ? sport1 has independent framing for the receive and trans- mit sections. sections run in a frameless mode or with frame synchronization signals internally or externally generated. frame synchronization signals are active high or inverted, with either of two pulsewidths and timings. ? sport1 supports serial data word lengths from 3 bits to 16 bits and provides optional a-law and -law companding according to itu (formerly ccitt) recommendation g.711.
admc326 C9C rev. c ? sport1 receive and transmit sections can generate unique interrupts on completing a data word transfer. ? sport1 can receive and transmit an entire circular buffer of data with only one overhead cycle per data word. an interrupt is generated after a data buffer transfer. ? sport1 can be configured to have two external interrupts (irq0 and irq1), and the flag in and flag out signals. the internally generated serial clock may still be used in this configuration. ? sport1 has two data receive pins (dr1a and dr1b), which are internally multiplexed onto the one dr1 port of the sport1. the particular data receive pin selected is deter- mined by a bit in the modectrl register. pin function description the admc326 is available in a 28-lead soic package and a 28-lead pdip package. table i describes the pins. table i. pin list group # of input/ name pins output function reset 1 i processor reset input sport1 1 6 i/o serial port 1 pins (tfs1, rfs1, dt1, dr1a, dr1b, sclk1) clkout 1 1 o processor clock output clkin, xtal 2 i, o external clock or quartz crystal connection point pio0?io8 1 9 i/o digital i/o port pins aux0?ux1 1 2 o auxiliary pwm outputs ah?l 6 o pwm outputs pwmtrip 1 i pwm trip signal v1, v2, v3 3 i analog inputs vaux0?aux2 3 i auxiliary analog input iconst 1 o adc constant current source v dd 1 power supply gnd 1 ground note 1 multipl exed pins, selectable individually through the piosel ect and piodata1 registers. interrupt overview the admc326 can respond to 16 different interrupt sources with minimal overhead, five of which are internal dsp core interr upts and 11 are from the motor control peripherals. the five dsp core interrupts are sport1 receive (or irq0 ) and trans- mit (or irq1 ), the internal timer, and two software interrupts. the motor control peripheral interrupts are the nine program- mable i/os and two from the pwm (pwmsync pulse and pwmtrip ). all motor control interrupts are multiplexed into the dsp core through the peripheral irq2 interrupt. the interrupts are internally prioritized and individually maskable. a detailed description of the entire interrupt system of the admc326 is presented later, following a more detailed description of each peripheral block. memory map the admc326 has two distinct memory types: program memory and data memory. in general, program memory contains user code and coefficients, while the data memory is used to store variables and data during program execution. both program memory ram and rom are provided on the admc326. pro- gram memory ram is arranged as one contiguous 512 24-bit block, starting at address 0x0000. program memory rom is a 4k 24-bit block located at address 0x0800. data memory is arranged as a 512 16-bit block starting at address 0x3800. the motor control peripherals are memory mapped into a region of the data memory space starting at 0x2000. the complete program and data memory maps are given in tables ii and iii, respectively. table ii. program memory map memory address range type function 0x0000?x002f ram interrupt vector table 0x0030?x01ff ram user program memory 0x0200?x07ff reserved 0x0800?x17ff rom user program memory 0x1800?x3fff reserved table iii. data memory map memory address range type function 0x0000?x1fff reserved 0x2000?x20ff memory mapped registers 0x2100?x37ff reserved 0x3800?x39ff ram user data memory 0x3a00?x3bff ram reserved 0x3c00?x3fff memory mapped registers system interface figure 4 shows a basic system configuration for the admc326 with an external crystal. admc326 xtal clkin 10mhz clkout reset 33pf 33pf figure 4. basic system configuration clock signals the admc326 can be clocked either by a crystal or a ttl- compatible clock signal. for normal operation, the clkin input cannot be halted, changed during operation, or operated below the specified minimum frequency. if an external clock is used, it should be a ttl-compatible signal running at half the instruction rate. the signal is connected to the clkin pin of the admc326. in this mode, with an external clock signal, the xtal pin must be left unconnected. the admc326 uses an input clock with a frequency equal to half the instruction rate; a 10 mhz input clock yields a 50 ns processor cycle (which is equivalent to 20 mhz). normally, instructions are executed in a single processor cycle. all device timing is relative to the internal instruction rate, which is indicated by the clkout signal when enabled. because the admc326 includes an on-chip oscillator feedback circuit, an external crystal may be used instead of a clock source, as
admc326 C10C rev. c shown in figure 4. the crystal should be connected across the clkin and xtal pins, with two capacitors as shown in figure 4. a parallel-resonant, fundamental frequency, microprocessor -grade crystal should be used. a clock output signal ( clkout) is generated by the processor at the processor? cycle rate of twice the input frequency. reset the admc326 dsp core and peripherals must be correctly reset when the device is powered up to assure p roper initialization. the admc326 contains an integrated power-on reset (por) circuit that provides a complete system reset on power-up and power-down. the por circuit monitors the voltage on the admc326 v dd pin and holds the dsp core and peripherals in reset while v dd is less than the threshold voltage level, v rst . when this voltage is exceeded, the admc326 is held in reset for an additional 2 16 dsp clock cycles (t rst in figure 5). on power-down, when the voltage on the v dd pin falls below v rst ? hyst , the admc326 will be reset. also, if the external reset pin is actively pulled low at any time after power-up, a complete hardware reset of the admc326 is initiated. v rst v dd reset v rst v hyst t rst figure 5. power-on reset operation the admc326 reset sets all internal stack pointers to the empty stack condition, masks all interrupts, clears the mstat register and performs a full reset of all of the motor control peripherals. following a power-up, it is possible to initiate a dsp core and motor control peripheral reset by pulling the reset pin low. the reset signal must meet the minimum pulsewidth specifi- cation, t rsp . following the reset sequence, the dsp core starts executing code from the internal pm rom located at 0x0800. dsp control registers the dsp core has a system control register, syscntl, memory mapped at dm (0x3fff). sport1 is configured as a serial port when bit 10 is set, or as flags and interrupt lines when this bit is cleared. for proper operation of the admc326, all other bits in this register must be cleared. the dsp core has a wait state control register, memwait, memory mapped at dm (0x3ffe). the default value of this register is 0xffff. for proper operation of the admc326 this register must be set to 0x8000. the configuration of both the syscntl and memwait registers of the admc326 are shown at the end of this data sheet. three-phase pwm controller overview the pwm generator block of the admc326 is a flexible, pro- grammable, three-phase pwm waveform generator that can be programmed to generate the required switching patterns to drive a three-phase voltage source inverter for ac induction motors (acim) or permanent magnet synchronous motors (pmsm). in addition, the pwm block contains special functions that consid- erably simplify the generation of the required pwm switching patterns for control of electronically commutated motors (ecm) or brushless dc motors (bdcm). the pwm generator produces three pairs of active high pwm signals on the six pwm output pins (ah, al, bh, bl, ch, and cl). the six pwm output signals consist of three high side drive signals (ah, bh, and ch) and three low side drive signals (al, bl, and cl). the switching frequency, dead time and minimum pulsewidths of the generated pwm patterns are pro- grammable using respectively the pwmtm, pwmdt, and pwmpd registers. in addition, three registers (pwmcha, pwmchb, and pwmchc) control the duty cycles of the three pairs of pwm signals. each of the six pwm output signals can be enabled or disabled by separate output enable bits of the pwmseg register. in addition, three control bits of the pwmseg register permit crossover of the two signals of a pwm pair for easy control of ecm or bdcm. in crossover mode, the pwm signal destined for the high side switch is diverted to the complementary low side output, and the signal destined for the low side switch is diverted to the corresponding high side output signal. in many applications, there is a need to provide an isolation barrier in the gate-drive circuits that turn on the power devices of the inverter. in general, there are two common isolation tech- niques: optical isolation using optocouplers, and transformer isolation using pulse transformers. the pwm controller of the admc326 permits mixing of the output pwm signals with a high frequency chopping signal to permit an easy interface to such pulse transformers. the features of this gate-drive chop- ping mode can be controlled by the pwmgate register. there is an 8-bit value within the pwmgate register that directly controls the chopping frequency. in addition, high frequency chopping can be independently enabled for the high side and the low side outputs using separate control bits in the pwmgate register. the pwm generator is capable of operating in two distinct modes: single update mode or double update mode. in single update mode, the duty cycle values are programmable only once per pwm period, so that the resultant pwm patterns are sym- metrical about the midpoint of the pwm period. in the double update mode, a second updating of the pwm duty cycle values is implemented at the midpoint of the pwm period. in this mode, it is possible to produce asymmetrical pwm patterns that pro- duce lower harmonic distortion in three-phase pwm inverters. this technique also permits the closed-loop controller to change the average voltage applied to the machine winding at a faster rate, allowing wider closed-loop bandwidths to be achieved. the operating mode of the pwm block (single or double update m ode) is selected by a control bit in modectrl register. the pwm generator of the admc326 also provides an internal signal that synchronizes the pwm switching frequency to the a/d operation. in single update mode, a pwmsync pulse is produced at the start of each pwm period. in double update mode, an additional pwmsync pulse is produced at the mid- point of each pwm period. the width of the pwmsync pulse is programmable through the pwmsyncwt register. the pwm signals produced by the admc326 can be shut off in a number of different ways. first, there is a dedicated asyn- chronous pwm shutdown pin, pwmtrip , which, when brought lo, instantaneously places all six pwm outputs in the off
admc326 C11C rev. c state. because this hardware shutdown mechanism is asynchro- nous, and the associated pwm disable circuitry does not use clocked logic, the pwm will shut down even if the dsp clock is not running. the pwm system may also be shut down from software by writing to the pwmswt register. status information about the pwm system of the admc326 is available to the user in the sysstat register. in particular, the state of pwmtrip is available, as well as a status bit that indi- cates whether operation is in the first half or the second half of the pwm period. a functional block diagram of the pwm controller is shown in figure 6. the generation of the six output pwm signals on pins ah to cl is controlled by four important blocks: ? the three-phase pwm timing unit, which is the core of the pwm controller, generates three pairs of complemented and dead-time-adjusted center-based pwm signals. ? the output control unit allows the redirection of the outputs of the three-phase timing unit for each channel to either the high side or the low side output. in addition, the output con- trol unit allows individual enabling/disabling of each of the six pwm output signals. ? the gate drive unit provides the high chopping frequency and its subsequent mixing with the pwm signals. ? the pwm shutdown controller manages the three pwm shutdown modes (via the pwmtrip pin, the analog block or the pwmswt register) and generates the correct reset signal for the timing unit. ? the pwm controller is driven by a clock at the same fre- quency as the dsp instruction rate, clkout, and is capable of generating two interrupts to the dsp core. one interrupt is generated on the occurrence of a pwmsync pulse, and the other is generated on the occurrence of any pwm shut- down action. pwmtrip or pwmswt (0) pwm shutdown controller pwmtrip pwmseg (8...0) output control unit gate drive unit clk pwm duty cycle registers pwm configuration registers to interrupt controller three-phase pwm timing unit clk reset sync sync pwmsync clkout ah al bh bl ch cl pwmgate (9...0) pwmtm (15...0) pwmdt (9...0) pwmpd (15...0) pwmsyncwt (7...0) modectrl (6) pwmcha (15...0) pwmchb (15...0) pwmchc (15...0) figure 6. overview of the pwm controller of the admc326 three-phase timing unit the 16-bit three-phase timing unit is the core of the pwm con- troller and produces three pairs of pulsewidth modulated signals with high resolution and minimal processor overhead. there are four main con?uration registers (pwmtm, pwmdt, pwmpd and pwmsyncwt) that determine the fundamental charac- teristics of the pwm outputs. in addition, the operating mode of the pwm (single or double update mode) is selected by bit 6 of the modectrl register. these registers, in conjunction with the three 16-bit duty cycle registers (pwmcha, pwmchb and pwmchc), control the output of the three-phase timing unit. pwm switching frequency: pwmtm register the pwm switching frequency is controlled by the pwm period register, pwmtm. the fundamental timing unit of the pwm controller is t ck = 1/f clkout where f clkout is the clkout f requency (dsp instruction rate). therefore, for a 20 mhz clkout, the fundamental time increment is 50 ns. the value written to the pwmtm register is effectively the number of t ck clock increments in half a pwm period. the required pwmtm value is a function of the desired pwm switching frequency (f pwm ) and is given by: pwmtm f f f f clkout pwm clkin pwm = = 2 therefore, the pwm switching period, t s , can be written as: t pwmtm t sck = 2 for example, for a 20 mhz clkout and a desired pwm switching frequency of 10 khz (t s = 100 s), the correct value to load into the pwmtm register is: pwmtm x e = = 20 10 21010 1000 0 3 8 6 3
admc326 C12C rev. c the largest value that can be written to the 16-bit pwmtm register is 0x ffff = 65,535, which corresponds to a minimum pwm switching frequency of: fhz pwm ,min , = = 20 10 2 65 535 153 6 for a clkout frequency of 20 mhz. pwm switching dead time: pwmdt register the second important pwm block parameter that must be initialized is the switching dead time. this is a short delay time introduced between turning off one pwm signal (for example ah) and turning on its complementary signal, al. this short time delay is introduced to permit the power switch being turned off to completely recover its blocking capability before the complementary switch is turned on. this time delay prevents a potentially destructive short-circuit condition from developing across the dc link capacitor of a typical voltage source inverter. dead time is controlled by the pwmdt register. the dead time is inserted into the three pairs of pwm output signals. the dead time, t d , is related to the value in the pwmdt register by: t pwmdt t pwmdt f dck clkout == 22 therefore, a pwmdt value of 0x00a (= 10), introduces a 1 s delay between the turn-off of any pwm signal (for example ah) and the turn-on of its complementary signal (al). the amount of the dead time can therefore be programmed in increments of 2 t ck (or 100 ns for a 20 mhz clkout). the pwmdt register is a 10-bit register. for a clkout rate of 20 mhz its maximum value of 0x3ff (= 1023) corresponds to a maximum programmed dead time of: t dmax = 1023 2 t ck = 1023 2 50 10 9 sec = 102 s the dead time can be programmed to zero by writing 0 to the pwmdt register. pwm operating mode: modectrl and sysstat registers the pwm controller of the admcf326 can operate in two dis- tinct modes: single update mode and double update mode. the operating mode of the pwm controller is determined by the state of bit 6 of the modectrl register. if this bit is cleared, the pwm operates in the single update mode. setting bit 6 p laces the pwm in the double update mode. by default, following either a peripheral reset or power-on, bit 6 of the modectrl register is cleared. this means that the default operating mode is single update mode. in single update mode, a single pwmsync pulse is produced in each pwm period. the rising edge of this signal marks the start of a new pwm cycle and is used to latch new values from the pwm con guration registers (pwmtm, pwmdt, pwmpd and pwmsyncwt) and the pwm duty cycle registers (pwmcha, pwmchb and pwmchc) into the three-phase timing unit. the pwmseg register is also latched into the output control unit on the rising edge of the pwmsync pulse. in effect, this means that the parameters of the pwm signals can be updated only once per pwm period at the start of each cycle. thus, the generated pwm patterns are symmetrical about the midpoint of the switching period. in double update mode, there is an additional pwmsync pulse produced at the midpoint of each pwm period. the rising edge of this new pwmsync pulse is again used to latch new values of the pwm con guration registers, duty cycle registers and the pwmseg register. as a result, it is possible to alter both the characteristics (switching frequency, dead time, min imum pulse- width and pwmsync pulsewidth) and the output duty cycles at the midpoint of each pwm cycle. consequently, it is pos- sible to produce pwm switching patterns that are no longer symmetrical about the midpoint of the period (asymmetrical pwm patterns). in the double update mode, operation in the rst half or the second half of the pwm c ycle is indicated by bit 3 of the sysstat register. in double update mode, this bit is cleared during operation in the rst half of each pwm period (between the rising edge of the original pwmsync pulse and the rising edge of the new p wmsync pulse, which is introduced in double update mode). bit 3 of the sysstat register is set during the second half of each pwm period. if required, a user may determine the status of this bit during a pwmsync inter- rupt service routine. the advantages of the double update mode are that lower har- monic voltages can be produced by the pwm process and wider control bandwidths are possible. however, for a given pwm switching frequency, the pwmsync pulses occur at twice the rate in the double update mode. because new duty cycle values must be computed in each pwmsync interrupt service routine, there is a larger computational burden on the dsp in the double update mode. width of the pwmsync pulse: pwmsyncwt register the pwm controller of the admcf326 produces an internal pwm synchronization pulse at a rate equal to the pwm switching frequency in single update mode and at twice the pwm frequency in the double update mode. this pwmsync synchronizes the operation of the pwm unit with the a/d converter system. the width of this pwmsync pulse is programmable by the pwmsyncwt register. the width of the pwmsync pulse, t pwmsync , is given by: t t pwmsyncwt pwmsync ck = + () 1 which means that the width of the pulse is programmable from t ck to 256 t ck (corresponding to 50 ns to 12.8 s for a clkout rate of 20 mhz). following a reset, the pwmsyncwt register con- tains 0x27 (= 39) so that the default pwmsync width is 2.0 s. pwm duty cycles: pwmcha, pwmchb, pwmchc registers the duty cycles of the six pwm output signals are controlled by the three duty cycle registers, pwmcha, pwmchb, and pwmchc. the integer value in the register pwmcha controls the duty cycle of the signals on ah and al. pwmchb controls the duty cycle of the signals on bh and bl, and pwmchc controls the duty cycle of the signals on ch and cl. the duty cycle registers are programmed in integer counts of the funda- mental time unit, t ck , and de ne the desired on-time of the high-side pwm signal produced by the three-phase timing unit over half the pwm period. the switching signals produced by the three-phase timing unit are also adjusted to incorporate the programmed dead time value in the pwmdt register.
admc326 C13C rev. c the pwm is center-based. this means that in single update mode the resulting output waveforms are symmetrical and centered in the pwmsync period. figure 7 presents a typical pwm timing diagram illustrating the pwm-related registers (pwmcha, pwmtm, pwmdt, and pwmsyncwt) control over the waveform timing in both half cycles of the pwm period. the magnitude of each parameter in the timing diagram is determined by multiplying the integer value in each register by t ck (typically 50 ns). it may be seen in the timing diagram how dead time is incorporated into the waveforms by moving the switching edges away from the instants set by the pwmcha register. pwmcha 2 pwmdt pwmsyncwt + 1 pwmcha pwmtm pwmtm ah al pwmsync sysstat (3) 2 pwmdt figure 7. typical pwm outputs of three-phase timing unit in single update mode each swit ching edge is moved by an eq ual amount (pwmdt t ck ) to preserve the symmetrical output patterns. the pwmsync pulse, whose width is set by the pwmsyncwt register, is also shown. bit 3 of the sysstat register indicates which half cycle is active. this can be useful in double update mode, as will be discussed later. the resultant on-times of the pwm signals shown in figure 7 may be written as: t pwmcha pwmdt t t pwmtm pwmcha pwmdt t ah ck al ck = = 2 2 ( ) ( ) the corresponding duty cycles are: d t t pwmcha pwmdt pwmtm d t t pwmtm pwmcha pwmdt pwmtm ah ah s al al s == == obviously, negative values of t ah and t al are not permitted because the minimum permissible value is zero, corresponding to a 0% duty cycle. in a similar fashion, the maximum value is t s , corresponding to a 100% duty cycle. the output signals from the timing unit for operation in double update mode are shown in figure 8. this illustrates a completely general case where the switching frequency, dead time and duty cycle are all changed in the second half of the pwm period. of course, the same value for any or all of these quantities could be used in both halves of the pwm cycle. however, it can be seen that there is no guarantee that symmetrical pwm signals will be produced by the timing unit in this double update mode. addi- tionally, it is seen that the dead time is inserted into the pwm signals in the same way as in the single update mode. pwmcha 2 pwmsyncwt 2 + 1 pwmcha 1 pwmtm 1 pwmtm 2 pwmsyncwt 1 + 1 ah al pwmsync sysstat (3) 2 pwmdt 1 2 pwmdt 2 figure 8. typical pwm outputs of three-phase timing unit in double update mode in general, the on-times of the pwm signals in double update mode are defined by: t ah = ( pwmcha 1 + pwmcha 2 pwmdt 1 pwmdt 2 ) t ck t al = ( pwmtm 1 + pwmtm 2 pwmcha 1 pwmcha 2 pwmdt 1 pwmdt 2 ) t ck where the subscript 1 refers to the value of that register during the first half cycle and the subscript 2 refers to the value during the second half cycle. the corresponding duty cycles are: d t t pwmcha pwmcha pwmtm pwmtm pwmdt pwmdt pwmtm pwmtm d t t pwmtm pwmtm pwmcha pwmtm pwmtm pwcha pwmdt pwmdt pwmtm pwmtm ah ah s al al s = = + () + () + () + () = = ++ () + () ? ++ () + () 12 12 12 12 12 1 12 212 12 because for the completely general case in double update mode, the switching period is given by: t s = ( pwmtm 1 + pwmtm 2 ) t ck again, the values of t ah and t al are constrained to lie between zero and t s . pwm signals similar to those illustrated in figure 7 and figure 8 can be produced on the bh, bl, ch, and cl outputs by programming the pwmchb and pwmchc registers in a manner id entical to that described for pwmcha. the pwm controller does not produce any pwm outputs until all of the pwmtm, pwmcha, pwmchb, and pwmchc registers have been written to at least once. after these registers have been written, the counters in the three-phase timing unit are enabled. writing to these registers also starts the main pwm timer. if during initialization, the pwmtm register is written
admc326 C14C rev. c after the pwmcha, pwmchb, and pwmchc registers, then the first pwmsync pulse (and interrupt if enabled) will be generated (1.5 t ck pwmtm) seconds after the initial write to the pwmtm register in single update mode. in d ouble update mode, the first pwmsync pulse will be generated (t ck pwmtm) seconds after the initial write to the pwmtm register in single update mode. effective pwm resolution in single update mode, the same values of pwmcha, pwmchb and pwmchc are used to define the on-times in both half cycles of the pwm period. as a result, the effective resolution of the pwm generation process is 2 t ck (or 100 ns for a 20 mhz clkout) since incrementing one of the duty cycle registers by one changes the resultant on-time of the associated pwm sig- nals by t ck in each half period (or 2 t ck for the full period). in double update mode, improved resolution is possible since different values of the duty cycles registers are used to define the on-times in both the first and second halves of the pwm period. as a result, it is possible to adjust the on-time over the whole period in increments of t ck . this corresponds to an effective pwm resolution of t ck in double update mode (or 50 ns for a 20 mhz clkout). the achievable pwm switching frequency at a given pwm resolution is tabulated in table iv. table iv. achievable pwm resolution in single and double update modes resolution single update mode double update mode (bit) pwm frequency (khz) pwm frequency (khz) 8 39.1 78.1 9 19.5 39.1 10 9.8 19.5 11 4.9 9.8 12 2.4 4.9 minimum pulsewidth: pwmpd register in many power converter switching applications, it is desirable to eliminate pwm switching pulses shorter than a certain width. it takes a finite time to both turn on and turn off modern power semiconductor devices. therefore, if the width of any of the pwm pulses is shorter than some minimum value, it may be desirable to completely eliminate the pwm switching for that particular cycle. the allowable minimum on-time for any of the six pwm out- puts for half a pwm period that can be produced by the pwm controller may be programmed using the pwmpd register. the minimum on-time is programmed in increments of t ck so that the minimum on-time that will be produced for any half pwm period, t min , is related to the value in the pwmpd register by: t min = pwmpd t ck a pwmpd value of 0x002 defines a permissible minimum on-time of 100 ns for a 20 mhz clkout. in each half cycle of the pwm, the timing unit checks the on-time of each of the six pwm signals. if any of the times is found to be less than the value specified by the pwmpd register, the corresponding pwm signal is turned off for the entire half period, and its complementary signal is turned completely on. consider the example where pwmtm = 200, pwmcha = 5, pwmdt = 3, and pwmpd = 10 with a clkout of 20 mhz while operating in single update mode. for this case, the pwm switching frequency is 50 khz and the dead time is 300 ns. the minimum permissible on-time of any pwm signal over one-half of any period is 500 ns. clearly, for this example, the dead-time adjusted on-time of the ah signal for one-half a pwm period is (5 3) 50 ns = 100 ns. because this is less than the minimum permissible value, output ah of the timing unit will remain off (0% duty cycle). additionally, the al signal will be turned on for the entire half period (100% duty cycle). output control unit: pwmseg register the operation of the output cont rol unit is managed by the 9-bit read/write pwmseg register. this register sets two distinct features of the output control unit that are directly useful in the control of ecm or bdcm. the pwmseg register contains three crossover bits, one for each pair of pwm outputs. setting bit 8 of the pwmseg register enables the crossover mode for the ah/al pair of pwm signals; setting bit 7 enables crossover on the bh/bl pair of pwm signals; and setting bit 6 enables crossover on the ch/cl pair of pwm signals. if crossover mode is enabled for any pair of pwm signals, the high-side pwm signal from the timing unit (for example ah) is diverted to the associated low-side output of the output control unit so that the signal will ultimately appear at the al pin. of course, the corresponding low-side output of the timing unit is also diverted to the complementary high-side output of the output control unit so that the signal appears at pin ah. following a reset, the three crossover bits are cleared so that the crossover mode is disabled on all three pairs of pwm signals. the pwmseg register also contains six bits (bits 0 to 5) that can be used to individually enable or disable each of the six pwm outputs. if the associated bit of the pwmseg register is set, the corresponding pwm output is disabled regardless of the value of the corresponding duty cycle register. this pwm output signal will remain in the off state as long as the corresponding enable/disable bit of the pwmseg register is set. the pwm output enable function gates the crossover function. after a reset, all six enable bits of the pwmseg register are cleared, thereby enabling all pwm outputs by default. in a manner identical to the duty cycle registers, the pwmseg is latched on the rising edge of the pwmsync signal so that ch anges to this register only become effective at the start of each pwm cycle in single update mode. in double update mode, the pwmseg reg- ister can also be updated at the midpoint of the pwm cycle. in the control of an ecm, only two inverter legs are switched at any time, and often the high-side device in one leg must be switched on at the same time as the low-side driver in a second leg. therefore, by programming identical duty cycles for two pwm channels (for example, let pwmcha = pwmchb) and setting bit 7 of the pwmseg register to crossover the bh/bl pair of pwm signals, it is possible to turn on the high-side switch of phase a and the low-side switch of phase b at the same time. in the control of an ecm, one inverter leg (phase c in this example) is disabled for a number of pwm cycles. this disable may be implemented by disabling both the ch and cl pwm outputs by setting bits 0 and 1 of the pwmseg register. t his is illus- trated in figure 9 where it can be seen that both the ah and bl signals are identical, because pwmcha = pwmchb, and the crossover bit for phase b is set. in addition, the other four signals (al, bh, ch, and cl) have been disabled by setting the appropriate enable/disable bits of the pwmseg register.
admc326 C15C rev. c for the situation illustrated in figure 9, the appropriate value for the pwmseg register is 0x00a7. in ecm operation, because each inverter leg is disabled for certain periods of time, the pwmseg register is changed based upon the position of the rotor shaft (motor commutation). ah al bh bl ch cl pwmtm pwmtm pwmcha = pwmchb pwmcha = pwmchb 2 pwmdt 2 pwmdt figure 9. an example of pwm signals suitable for ecm control. pwmcha = pwmchb, bh/bl are a crossover pair. al, bh, ch and cl outputs are disabled. operation is in single update mode. gate drive unit: pwmgate register the gate drive unit of the pwm controller adds features that simplify the design of isolated gate drive circuits for pwm inverters. if a transformer-coupled power device gate drive amplifier is used, the active pwm signal must be chopped at a high frequency. the pwmgate register allows the program- ming of this high frequency chopping mode. the chopped active pwm signals may be required for the high-side drivers only, for the low-side drivers only, or for both the high-side and low-side switches. therefore, independent control of this mode for both high- and low-side switches is included with two separate con- trol bits in the pwmgate register. typical pwm output signals with high-frequency chopping enabled on both high-side and low-side signals are shown in figure 10. chopping of the high-side pwm outputs (ah, bh, and ch) is enabled by setting bit 8 of the pwmgate register. chopping of the low-side pwm outputs (al, bl, and cl) is enabled by setting bit 9 of the pwmgate register. the high chopping frequency is controlled by the 8-bit word (gdclk) written to bits 0 to 7 of the pwmgate register. the period and the frequency of this high frequency carrier are: t gdclk t f f gdclk chop ck chop clkout = + () [] = + () [] 41 41 the gdclk value may range from 0 to 255, corresponding to a programmable chopping frequency rate from 19.5 khz to 5 mhz for a 20 mhz clkout rate. the gate drive features must be programmed before operation of the pwm controller and typically are not changed during normal operation of the pwm controller. following a reset, by default, all bits of the pwmgate register are cleared so that high frequency chop- ping is disabled. pwmtm pwmtm [4 (gdclk+1) t ck ] 2 pwmdt 2 pwmdt pwmcha pwmcha figure 10. typical pwm signals with high frequency gate chopping enabled on both high-side and low-side switches (gdclk is the integer equivalent of the value in bits 0 to 7 of the pwmgate register.) pwm shutdown in the event of external fault conditions, it is essential that the pwm system be instantaneously shut down. two methods of sensing a fault condition are provided by the admc326. for the first method, a low level on the pwmtrip pin initiates an instantaneous, asynchronous (independent of dsp clock) s hut- down of the pwm controller. this places all six pwm outputs in the off state, disables the pwmsync pulse and associated interrupt signal and generates a pwmtrip interrupt signal. the pwmtrip pin has an internal pull-down resistor so that even if the pin becomes disconnected, the pwm outputs will be disabled. the state of the pwmtrip pin can be read from bit 0 of the sysstat register. the second method for detecting a fault condition is through the i sense pin in the analog block of the admc326. the i sense pin monitors the feedback signals from a dc bus current sensing resistor that represents the total current in the motor. when the voltage of i sense goes below i sense trip threshold, pwmtrip will be internally pulled low. the negative edge of the internal pwmtrip will generate a shutdown in the same manner as a negative edge on pin pwmtrip . it is possible through software to initiate a pwm shutdown by writing to the 1-bit read/write pwmswt register (0x2061). writing to this bit generates a pwm shutdown in a manner identical to the pwmtrip or i sense pins. following a pwm shutdown, it is possible to determine if the shutdown was gener- ated from hardware or software by reading the same pwmswt register. reading this register also clears it. restarting the pwm after a fault condition is detected requires clearing the fault and reinitializing the pwm. clearing the fault requires that pwmtrip returns to a hi state and i sense returns to a voltage greater than the i sense trip threshold. after the fault has been cleared, the pwm can be restarted by writing to registers pwmtm, pwmcha, pwmchb and pwmchc. a fter the fault is cleared and the pwm registers are initialized, internal timing of the three-phase timing unit will resume, and the new duty cycle values will be latched on the next rising edge of pwmsync. pwm registers the configuration of the pwm registers is described at the end of the data sheet. the parameters of the 16-bit pwm timer is tabulated in table v. adc overview the adc of the admc326 is based upon the single slope conversion technique. this approach offers an inherently monotonic conversion process and, to within the noise and sta- bility of its components, there will be no missing codes.
admc326 C16C rev. c table vi. adc auxiliary channel selection modectrl (1) modectrl (0) select adcmux1 adcmux0 vaux0 0 0 vaux1 0 1 vaux2 1 0 calibration (v ref )1 1 the single slope technique has been adapted on the admc326 for four channels that are simultaneously converted. refer to figure 11 for the functional schematic of the adc. three of the main inputs (v1, v2, and v3) are directly connected as high impedance voltage inputs. the fourth channel has been configured with a serially-connected 4-to-1 multiplexer. table vi shows the multiplexer input selection codes. one of these auxiliary multi- plexed channels is used to calibrate the ramp against the internal voltage reference (v ref ). vaux0 v2l vauxl pwmsync (convst) adc registers v1l v3l v2 (cap reset) clk modectrl<7> 12-bit adc timer block v ref comp adc registers adc1 adc2 adc3 adcaux modectrl<0..1> external charging cap v c iconst iconst_trim<2:0> vaux1 vaux2 comp comp comp v1 c gnd 4-to-1 mux v3 figure 11. adc overview comparing each adc input to a reference ramp voltage, and tim- ing the comparison of the two signals, performs the conversion process. the actual conversion point is the time point intersec- tion of the input voltage and the ramp voltage (v c ) as shown in figure 12. this time is converted to counts by the 12-bit adc timer block and is stored in the adc registers. the ramp volt- age used to perform the conversion is generated by driving a table v. fundamental characteristics of pwm generation unit of admc326 16-bit pwm timer parameter min typ max unit counter resolution 16 bits edge resolution (single update mode) 100 ns edge resolution (double update mode) 50 ns programmable dead time range 0 100 s programmable dead time increments 100 ns programmable pulse deletion range 0 100 s programmable pulse deletion increments 100 ns pwm frequency range 150 hz pwmsync pulsewidth (t crst ) 0.05 12.5 s gate drive chop frequency range 0.02 5 mhz fixed current into an off-chip capacitor, where the cap acitor voltage is v c = (i/c) t following reset, v c = 0 at t = 0. this reset and the start of the conversion process are initiated by the pwmsync pulse, as shown in figure 12. the width of the pw msync pulse is controlled by the pwmsyncwt register and should be programmed according to fig ure 13 to ensure comp lete reset ting. in order to compensate for ic process manufacturing tolerances (and to adjust for capacitor tolerances), the current source of the admc326 is software progr ammable. the software setting of the magnitude of the iconst c urrent generator is accomplished by selecting one of eight steps over an approximately 20% cur- rent range. v1 pwmsync v vil comparator output t t crst t pwm t crst t vil v c v cmax figure 12. analog input block operation the adc system consists of four comparators and a single timer, which may be clocked at either the dsp rate or half the dsp rate depending on the setting of the adccnt bit (bit 7) of the modectrl register. when this bit is cleared, the timers count at a slower rate of clkin. when this bit is set, they count at clkout or twice the rate of clkin. adc1, adc2, adc3, and adcaux are the registers that capture the conversion times, which are effectively the timer value when the associated com- parator trips.
admc326 C17C rev. c charging capacitor nf 0 2 decimal counts 50 100 150 200 46810 0 figure 13. pwmsyncwt program value adc resolution the adc is intrinsically linked to the pwm block through the pwmsync pulse controlling the adc conversion process. because of this link, the effective resolution of the adc is a function of both the pwm switching frequency and the rate at which the adc counter timer is clocked. for a clkout period of t ck and a pwm period of t pwm , the maximum count of the adc is given by: max count = min (4095, ( t pwm t crst )/2 t ck ) for modectrl bit 7 = 0 max count = min (4095, ( t pwm t crst )/ t ck ) for modectrl bit 7 = 1 where t pwm is equal to the pwm period if operating in single update mode, or it is equal to half that period if operating in double update mode. for an assumed clkout frequency of 20 mhz and pwmsync pulsewidth of 2.0 s, the effective resolution of the adc block is tabulated for various pwm switching frequencies in table vii. table vii. adc resolution examples pwm modectrl[7] = 0 modectrl[7] = 1 freq. max effective max effective (khz) count resolution count resolution 2.4 4095 12 4095 12 4 2480 >11 4095 12 8 1230 >10 2460 >11 18 535 >9 1070 >10 25 380 >8 760 >9 charging capacitor selection the charging capacitor value is selected based on the sample (pwm) frequency desired. a selected capacitor value that is too small will reduce the available resolution of the adc by having the ramp voltage rise rapidly and convert too quickly, not utilizing all possible counts available in the pwm cycle. too large a capacitor may not convert in the available pwm cycle, returning 0xfff. to select a charging capacitor use figure 14, select the s ampling frequency desired, then determine if the cur- rent source is to be tuned to a nominal 100 a or left in the default (0x0 code) trim state, then determine the proper charge capacitor from the appropriate curve. pwm frequency khz 100 1 1 100 10 c nom nf 10 default iconst tuned iconst figure 14. timing capacitor selection programmable current source the admc326 has an internal current source that is used to charge an external capacitor, generating the voltage ramp used for conversion. the magnitude of the output of the current source circuit is subject to manufacturing variations and can vary from one device to the next. therefore, the admc326 incudes a pro- gramma ble current source whose output can always be tuned to within 5% of the target 100 a. a 3-bit register, iconst_trim, allows the user to make this adjustment. the output current is proportional to the value written to the register: 0x0 produces the minimum output, and 0x7 produces the maximum output. the default value of iconst_trim after reset is 0x0. adc reference ramp calibration the peak of the adc ramp voltage should be as close as pos- sible to 3.5 v to achieve the optimum adc resolution and signal range. when the current source is in the default state, the peak of the adc ramp slope will be lower than this 3.5 v target ramp. when the current source value is increased, the adc ramp slope will become closer to the target value. the tuned ramp slope is the one closest to the target ramp. a simple calibration procedure using the internal 2.5 v reference voltage allows the selection of the iconst_trim register value to reach this tuned ramp slope: 1. a high quality linear adc capacitor is selected using figure 14 for a tuned iconst. 2. program pwmsyncwt to proper count as in figure 13. 3. the adc max count is calculated, as described in the adc resolution section. 4. the target reference conversion count is calculated as target = (max count) (2.5 v/3.5 v). 5. reset or software sets the iconst_trim register to zero. 6. select the calibration v ref in software on adc multiplexer and wait one pwm cycle for updated adc value. 7. the calibration channel value is compared with the target reference conversion. 8. if this value is greater than the target, the iconst_trim value is incremented by one, and step 7 is repeated. 9. if the calibration channel value is less than the target, the calibration is completed.
admc326 C18C rev. c v ref 3.5v 0.3v minimum ramp target ramp figure 15. current ramp adc registers the configuration of all registers of the adc system is shown at the end of the data sheet. auxiliary pwm timers overview the admc326 provides two variable frequency, variable duty cycle, 8-bit, auxiliary pwm outputs that are available at the aux1 and aux0 pins when enabled. these auxiliary pwm outputs can be used to provide switching signals to other cir- cuits in a typical motor control system such as power factor corrected front-end converters or other switching power con- verters. alternatively, by addition of a suitable filter network, the auxiliary pwm output signals can be used as simple single- bit digital-to-analog converters. the auxiliary pwm system of the admc326 can operate in two different modes: independent mode, or offset mode. the operating mode of the auxiliary pwm system is controlled by bit 8 of the modectrl register. setting bit 8 of the modectrl register places the auxiliary pwm system in the independent mode. in this mode, the two auxiliary pwm generators are completely independent and separate switching frequencies and duty cycles may be programmed for each auxiliary pwm out put. in this mode, the 8-bit auxtm0 register sets the switching fre- quency of the signal at the aux0 output pin. similarly, the 8-bit auxtm1 register sets the switching frequency of the sig- nal at the aux1 pin. the fundamental time increment for the auxiliary pwm outputs is twice the dsp instruction rate (or 2 t ck ) and the corresponding switching periods are given by: t aux 0 = 2 ( auxtm 0 + 1) t ck t aux 1 = 2 ( auxtm 1 + 1) t ck since the values in both auxtm 0 and auxtm 1 can range from 0 to 0xff, the achievable switching frequency of the auxil- iary pwm signals may range from 39.1 khz to 10 mhz for a clkout frequency of 20 mhz. the on-time of the two auxiliary pwm signals is programmed by the two 8-bit auxch0 and auxch1 registers, according to: t on , aux 0 = 2 ( auxch 0) t ck t on , aux 1 = 2 ( auxch 1) t ck so that output duty cycles from 0% to 100% are possible. duty cycles of 100% are produced if the on-time value exceeds the period value. typical auxiliary pwm waveforms in independent mode are shown in figure 16(a). when bit 8 of the modectrl register is cleared, the auxiliary pwm channels are placed in offset mode. in offset mode, the switching frequency of the two signals on the aux0 and aux1 pins are identical and controlled by auxtm0 in a manner similar to that previously described for independent mode. in addition, the on times of both the aux0 and aux1 signals are controlled by the auxch0 and auxch1 registers as before. however, in this mode the auxtm1 register defines the offset time from the rising edge of the signal on the aux0 pin to that on the aux1 pin according to: t offset = 2 ( auxtm 1 + 1) t ck for correct operation in this mode, the value written to the auxtm 1 register must be less than the value written to the auxtm 0 register. typical auxiliary pwm waveforms in offset mode are shown in figure 16(b). again, duty cycles from 0% to 100% are possible in this mode. in both operating modes, the resolution of the auxiliary pwm system is eight bits only at the minimum switching frequency (auxtm0 = auxtm1 = 255 in independent mode, auxtm0 = 255 in offset mode). obviously, as the switching frequency is increased, the resolution is reduced. values can be written to the auxiliary pwm registers at any time. however, new duty cycle values written to the auxch0 and auxch1 registers only become effective at the start of the next cycle. writing to the auxtm0 or auxtm1 registers causes the internal timers to be reset to 0 and new pwm cycles to begin. by default following a reset, bit 8 of the modectrl register is cleared, thus enabling offset mode. in addition, the registers auxtm0 and auxtm1 default to 0xff, corresponding to the minimum switching frequency and zero offset. the on-time reg- isters auxch0 and auxch1 default to 0x00. auxiliary pwm interface, registers and pins the registers of the auxiliary pwm system are summarized at the end of the data sheet. aux0 aux1 2 (auxtm0 + 1) 2 (auxtm1 + 1) 2 auxch1 2 auxch1 2 auxch0 (a) independent mode aux0 aux1 2 (auxtm1 + 1) 2 (auxtm0 + 1) 2 auxch0 2 (auxtm0 + 1) 2 auxch1 (b) offset mode figure 16. typical auxiliary pwm signals. (all times in increments of t ck )
admc326 C19C rev. c pwm dac equation the auxiliary pwm output can be filtered in order to produce a low frequency analog signal between 0 v to v dd . for example, a 2-pole filter with a 1.2 khz cutoff frequency will sufficiently atten uate the pwm carrier. figure 17 shows how the filter would be applied. c1 c2 r1 r2 r1 = r2 = 13k c1 = c2 = 10nf auxpwm figure 17. auxiliary pwm output filter watchdog timer the admc326 incorporates a watchdog timer that can perform a full reset of the dsp and motor control peripherals in the event of software error. the watchdog timer is enabled by writ- ing a timeout value to the 16-bit wdtimer register. the tim eout value represents the number of clkin cycles required for the watchdog timer to count down to zero. when the watchdog timer reaches zero, a full dsp core and motor control peripheral reset is performed. in addition, bit 1 of the sysstat register is set so that after a watchdog reset, the admc326 can determine that the reset was due to the timeout of the watchdog timer and not an external reset. following a watchdog reset, bit 1 of the sysstat register may be cleared by writing zero to the wdtimer register. this clears the status bit but does not enable the watchdog timer. on reset, the watchdog timer is disabled and is only enabled when the first timeout value is written to the wdtimer register. to prevent the watchdog timer from timing out, the user must write to the wdtimer register at regular intervals (shorter than the programmed wdtimer period value). on all but the first write to wdtimer, the particular value written to the register is unimportant since writing to wdtimer simply reloads the first value written to this register. programmable digital input/output the admc326 has nine programmable digital input/output (pio) pins that are all multiplexed with other functions. the nine pio lines pio0 pio8 are multiplexed with the serial port (pins pio0/tfs1 to pio5/rfs1), the clkout (pin pio6/ clkout) and the auxiliary pwm outputs (pins pio7/aux1 and pio8/aux0). when configured as a pio, each of these nine pins can act as an input, output, or an interrupt source. the operating mode of pins pio0/tfs1 to pio7/aux1 is con- trolled by the pioselect register. this 8-bit register has a bit for each input so that the mode of each pin may be selected individually. bit 0 of pioselect controls the operation of the pio0/tfs1 pin. bit 1 controls the pio1/dt1 pin, etc. setting the appropriate bit in the pioselect register causes the cor- responding pin to be configured for pio functionality. clearing the bit selects the alternate (sport, clkout, or auxpwm) table viii. auxiliary pwm timers parameter test conditions min typ max unit resolution 8 bits pwm frequency 10 mhz clkin 0.039 mhz mode of the corresponding pin. following power-on reset, all bits of pioselect are set such that pio functionality is selected. the operating mode of the pio8/aux0 pin is selected by bit 1 of the piodata1 register. in a manner identical to the pioselect register, setting this bit enables pio functionality (pio8) while clearing the bit enables auxiliary pwm functional- ity (aux0). once pio functionality has been selected for any or all of these nine pins, the direction may be set by the 8-bit piodir0 register (for pio0 to pio7) and the 1-bit piodir1 register (for pio8). clearing any bit configures the corresponding pio line as an input while setting the bit configures it as an output. by default, following a reset, all bits of piodir0 and piodir1 are cleared configuring the pio lines as inputs. the data of the pio0 to pio8 lines is controlled by the piodata0 register (for pio0 to pio7) and bit 0 of the piodata1 register (for pio8). these registers can be used to read data from those pio lines configured as inputs and write d ata to those configured as outputs. any of the nine pins that have been configured for pio functionality can be made to act as an interrupt source by setting the appropriate bit of the piointen0 register (for pio0 to pio7) or the piointen1 register (for pio8). in order to act as an interrupt source the pin must also be configured as an input. an interrupt is generated upon a change of state (low-to-high transition or high-to-low transition) on any input that has been configured as an interrupt source. following a change of state event on any such input, the corresponding bit is set in the pioflag0 register (for pio0 to pio7) and pioflag1 (for pio8) and a common pio interrupt is generated. reading the pioflag0 and pioflag1 registers permits determining the interrupt source. reading the pioflag0 and pioflag1 registers automatically clears all bits of the reg- isters. following power-on or reset, all bits of piointen0 and piointen1 are cleared so that no interrupts are enabled. each pio line has an internal pull-down resistor so that follow- ing power-on or reset all nine lines are configured as input pios and will be read as logic lows if left unconnected. multiplexing of pio lines the pio0 pio5 lines are multiplexed on the admc326 with the functional lines of the serial port, sport1. although the pioselect register permits individual selection of the function- ality of each pin, certain restrictions apply when using sport1 for serial communications. in general, when transmitting and receiving data on the dti and drib pins, respectively, the pio0/tfs1 and pio5/rfs1 pins must also be selected for sport (tfs1 and rfs1) functionality even if unframed communication is implemented. t herefore, when using sport1 for any type of serial communication, the minimal setting for pioselect is 0xd8 (i.e., select dti, d rib, rfs1, and tfs1; select pio7, pio6, pio4, pio3 as digital i/o).
admc326 C20C rev. c if the serial port communications use an internally generated sclk1, the pio3/sclk1 pin may be used as a general-pu rpose pio line. when external sclk mode is selected, the pio/sclk1 pin must be enabled as sclk1 (pioselect [3] = 0). when the drib data receive line of sport1 is selected as the data receive line (modectrl [4] = 1), the pio4/dria line may be used as a general purpose pio pin. when the dria data receive line of sport1 is selected as the data receive line (modectrl [4] = 0, the pio2/drib line may be used as a general-purpose pio pin. the functionality of the pio6/clkout, pio7/aux1, and pio8/aux0 pins may be selected on a pin-by-pin basis as desired. pio registers the configuration of all registers of the pio system is shown at the end of the data sheet. interrupt control the admc326 can respond to 16 different interrupt sources, some of which are generated by internal dsp core interrupts and others from the motor control peripherals. the dsp core interrupts include the following: ? a peripheral (or irq2 ) interrupt. ? a sport1 receive (or irq0 ) and a sport1 transmit (or irq1 ) interrupt. ? two software interrupts. ? an interval timer time-out interrupt. the interrupts generated by the motor control peripherals include: ? a pwmsync interrupt. ? nine programmable input/output (pio) interrupts. ? a pwm trip interrupt. the core interrupts are internally prioritized and individually maskable. all peripheral interrupts are multiplexed into the dsp core through the peripheral ( irq2 ) interrupt. the pwmsync interrupt is triggered by a low-to-high transition on the pwmsync pulse. the pwmtrip interrupt is triggered on a high-to-low transition on the pwmtrip pin, an overcurrent on the i sense pin, or by writing to the pwmswt register. a pio interrupt is detected on any change of state (high- to-low or low-to-high) on the pio lines. the admc326 interrupt control system is configured and controlled by the ifc, imask, and icntl registers of the dsp core and by the irqflag register for the pwmsync and pwmtrip interrupts. pio interrupts are enabled and dis- abled by the piointen0 and piointen1 registers. table ix. interrupt vector addresses interrupt vector interrupt source address pwmtrip 0x002c (highest priority) peripheral interrupt ( irq2 ) 0x0004 pwmsync 0x000c pio 0x0008 software interrupt 1 0x0018 software interrupt 0 0x001c sport1 transmit interrupt (or irq1) 0x0020 sport1 receive interrupt (or irq0) 0x0024 timer 0x0028 (lowest priority) interrupt masking interrupt masking (or disabling) is controlled by the imask register of the dsp core. this register contains individual bits that must be set to enable the various interrupt sources. if any peripheral interrupt (pwmsync, pwmtrip or pio) is to be enabled, the irq2 interrupt enable bit (bit 9) of the imask register must be set. the configuration of the imask register of the admc326 is shown at the end of the data sheet. interrupt configuration the ifc and icntl registers of the dsp core control and configure the interrupt controller of the dsp core. the ifc register is a 16-bit register that may be used to force and/or clear any of the eight dsp interrupts. bits 0 to 7 of the ifc register may be used to clear the dsp interrupts while bits 8 to 15 can be used to force a corresponding interrupt. writing to bits 11 and 12 in ifc is the only way to create the two software interrupts. the icntl register is used to configure the sensitivity (edge or level) of the irq0 , irq1 and irq2 interrupts and to enable/ disable interrupt nesting. setting bit 0 of icntl configures the irq0 as edge-sensitive, while clearing the bit configures it for level-sensitive. bit 1 is used to configure the irq1 interrupt. bit 2 is used to configure the irq2 interrupt. it is recommended that the irq2 interrupt always be configured as level-sensitive to ensure that no peripheral interrupts are lost. setting bit 4 of the icntl register enables interrupt nesting. interrupt operation following a reset, the rom code on the admc326 must copy a default interrupt vector table into program memory ram from address 0x0000 to 0x002f. since each interrupt source has a dedicated four-word space in this vector table, it is pos- sible to code short interrupt service routines (isrs) in place. alternatively, it may be necessary to insert a jump instruction to the appropriate start address of the interrupt service routine if more memory is required for the isr. when an interrupt occurs, the program sequencer ensures that there is no latency (beyond synchronization delay) when pro- cessing unmasked interrupts. in the case of the timer, sport1, and software interrupts, the interrupt controller automatically jumps to the appropriate location in the interrupt vector table. at this point, a jump instruction to the appropriate isr is required. motor control peripheral interrupts are slightly different. when a peripheral interrupt is detected, a bit is set in the irqflag register for pwmsync and pwmtrip or in the pioflag0, or pioflag1 registers for a pio interrupt, and the irq2 line is pulled low until all pending interrupts are acknowledged. the dsp software must determine the source of the interrupts by reading irqflag register. if more than one interrupt occurs simultaneously, the higher priority interrupt service routine is executed. reading the irqflag register clears the pwmtrip and pwmsync bits and acknowledges the interrupt, thus allowing further interrupts when the isr exits. a user s pio interrupt service routine must read the pioflag0 and pioflag1 registers to determine which pio port is the source of the interrupt. reading registers pioflag0 and pioflag1 clears all bits in the registers and acknowledges the interrupt, thus allowing further interrupts after the isr exits. the configuration of all these registers is shown at the end of the data sheet.
admc326 C21C rev. c system controller the system controller block of the admc326 performs the fol- lowing functions: 1. manages the interface and data transfer between the dsp core and the motor control peripherals. 2. handles interrupts generated by the motor control peripher- als and generates a dsp core interrupt signal irq2 . 3. controls the adc multiplexer select lines. 4. enables pwmtrip and pwmsync interrupts. 5. controls the multiplexing of the sport1 pins to select either dr1a or dr1b data receive pins. it also allows configura- tion of sport1 as a uart interface. 6. controls the pwm single/double update mode. 7. controls the adc conversion time modes. 8. controls the auxiliary pwm operation mode. 9. contains a status register (sysstat) that indicates the state of the pwmtrip pin, the watchdog timer, and the pwm timer. 10. performs a reset of the motor control peripherals and con- trol registers following a hardware, software, or watchdog initiated reset. sport1 control both data receive pins are multiplexed internally into the single data receive input of sport1 as shown in figure 18. two cont rol bits in the modectrl register control the state of the sport1 pins by manipulating internal multiplexers in the admc326. dsp core sport1 pio4/dr1a pio2/dr1b pio0/tfs1 pio5/rfs1 pio3/sclk1 modectrl (5 . . . 4) uarten dr1sel dt1 dr1 tfs1 rfs1 sclk1 fl1 pio1/dt1 admc326 figure 18. internal multiplexing of sport1 pins bit 4 of the modectrl register (dr1sel) selects between the two data receive pins. setting bit 4 of modectrl con- nects pin dr1b to the internal data receive port dr1 of sport1. clearing bit 4 connects dr1a to dr1. setting bit 5 of the modectrl register (sport1 mode) configures the serial port for uart mode. in this mode, the dr1 and rfs1 pins of the internal serial port are connected together. additionally, setting the sport1 mode bit con- nects the fl1 flag of the dsp to the external pio5/rfs1 pin. flag pins the admc326 provides flag pins. the alternate configuration of sport1 includes a flag in (fi) and flag out (fo) pin. this alternate configuration of sport1 is selected by bit 10 of the dsp system control register, syscntl at data memory address, 0x3fff. in the alternate configuration, the dr1 pin (either dr1a or dr1b depending upon the state of the dr1sel bit) becomes the fi pin and the dt1 pin becomes the fo pin. additionally, rfs1 is configured as the irq0 interrupt input and tfs1 is configured as the irq1 interrupt. the serial port clock, sclk1, is still available in the alternate configuration. development tools users are recommended to obtain the admcf326-evalkit from analog devices. the tool kit contains everything required to quickly and easily evaluate and develop applications using the admcf326 and admc326 dsp motor controllers. please contact your adi sales representative for ordering information.
admc326 C22C rev. c table xi. dsp core registers address name bits function 0x3fff syscntl [15 . . . 0] system control register 0x3ffe memwait [15 . . . 0] memory wait state control register 0x3ffd tperiod [15 . . . 0] interval timer period register 0x3ffc tcount [15 . . . 0] interval timer count register 0x3ffb tscale [7 . . . 0] interval timer scale register 0x3ffa . . . f3 reserved 0x3ff2 sport1_ctrl_reg [15 . . . 0] sport1 control register 0x3ff1 sport1_sclkdiv [15 . . . 0] sport1 clock divide register 0x3ff0 sport1_rfsdiv [15 . . . 0] sport1 receive frame sync divide 0x3fef sport1_autobuf_ctrl [15 . . . 0] sport1 autobuffer control register table x. peripheral register map address (hex) name bits used function 0x2000 adc1 [15 ...4] adc results for v1 0x2001 adc2 [15 ...4] adc results for v2 0x2002 adc3 [15 ...4] adc results for v3 0x2003 adcaux [15 ...4] adc results for vaux 0x2004 piodir0 [7 . . . 0] pio0 . . . 7 pins direction setting 0x2005 piodata0 [7 . . . 0] pio0 . . . 7 pins input/output data 0x2006 piointen0 [7 . . . 0] pio0 . . . 7 pins interrupt enable 0x2007 pioflag0 [7 . . . 0] pio0 . . . 7 pins interrupt status 0x2008 pwmtm [15 ...0] pwm p eriod 0x2009 pwmdt [9 . . . 0] pwm deadtime 0x200a pwmpd [9 . . . 0] pwm pulse deletion time 0x200b pwmgate [9 . . . 0] pwm gate drive configuration 0x200c pwmcha [15 ...0] pwm c hannel a pulsewidth 0x200d pwmchb [15 ...0] pwm c hannel b pulsewidth 0x200e pwmchc [15 ...0] pwm chan nel c pulsewidth 0x200f pwmseg [8 . . . 0] pwm segment select 0x2010 auxch0 [7 . . . 0] aux pwm output 0 0x2011 auxch1 [7 . . . 0] aux pwm output 1 0x2012 auxtm0 [7 . . . 0] auxiliary pwm frequency value 0x2013 auxtm1 [7 . . . 0] auxiliary pwm frequency value/offset reserved 0x2015 modectrl [8 . . . 0] mode control register 0x2016 sysstat [3 . . . 0] system status 0x2017 irqflag [1 . . . 0] interrupt status 0x2018 wdtimer [15 ...0] w atchdog timer 0x2019 . . . 43 reserved 0x2044 piodir1 [0] pio8 pin direction setting 0x2045 piodata1 [1 . . . 0] pio8 data and mode control 0x2046 piointen1 [0] pio8 pin interrupt enable 0x2047 pioflag1 [0] pio8 pin interrupt status 0x2048 reserved 0x2049 pioselect [7 . . . 0] pio0 to pio7 mode select 0x204a . . . 5f reserved 0x2060 pwmsyncwt [7 . . . 0] pwmsync pulsewidth 0x2061 pwmswt [0] pwm s/w trip bit 0x2062 . . . 67 reserved 0x2068 iconst_trim [2. . .0] iconst trim 0x2069 . . . ff reserved
admc326 C23C rev. c 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 000 00000 00000000 t d = 2 pwmdt f clkout seconds pwmdt (r/w) dm (0x2009) pwmdt f pwm = pwmtm (r/w) dm (0x2008) pwmtm 2 pwmtm f clkout 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 = enable 1 = disable ch output disable cl output disable bh output disable bl output disable ah output disable al output disable 0 = no crossover 1 = crossover a channel crossover b channel crossover c channel crossover dm (0x200f) pwmseg (r/w) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0000 000 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 010 00111 00000000 pwmsyncwt (r/w) dm (0x2060) pwmsyncwt t pwmsync, on = pwmsyncwt + 1 f clkout 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 000 00000 0000 00 0 0 pwmswt (r/w) dm (0x2061) figure 19. configuration of pwm registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d these bits should always be written as shown.
admc326 C24C rev. c 0 0 0 0 0 0 0 0 0 0 low side gate chopping 0 = disable 1 = enable high side gate chopping dm (0x200b) gdclk gate drive chopping frequency pwmgate (r/w) pwmpd (r/w) dm (0x200a) pwmpd pwmcha (r/w) pwm channel a duty cycle dm (0x200c) pwmchb (r/w) pwm channel b duty cycle dm (0x200d) pwmchc (r/w) dm (0x200e) pwm channel c duty cycle t min = pwmpd f clkout seconds f chop = 4 (gdclk + 1) f clkout 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 00 0 figure 20. configuration of additional pwm registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d these bits should always be written as shown.
admc326 C25C rev. c dm (0x2004) 0 = input 1 = output piodir0 (r/w) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2044) piodir1 (r/w) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2005) 0 = low level 1 = high level piodata0 (r/w) 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2045) pio8 data piodata1 (r/w) 0 0 0 00 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2049) pioselect (r/w) 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 pio8/aux0 mode 0 0 0 0 1 1 1 11 1 1 1 1 0 0 0 = tfs1 1 = pio0 0 = lo 1 = hi 0 = aux0 1 = pio8 pio0 pio7 pio8 pio0 pio7 0 = dt1 1 = pio1 0 = dr1b 1 = pio2 0 = sclk1 1 = pio3 0 = aux1 1 = pio7 0 = clkout 1 = pio6 0 = rfs1 1 = pio5 0 = dr1a 1 = pio4 0 = input 1 = output figure 21. configuration of pio registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d these bits should always be written as shown.
admc326 C26C rev. c pioflag0 (r) 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 0 00 0 0 0 pioflag1 (r) 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 0 00 0 0 0 dm (0x2007) 0 = no interrupt 1 = interrupt flagged dm (0x2047) 0 = no interrupt 1 = interrupt flagged 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 piointen0 (r/w) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2006) 0 = interrupt disable 1 = interrupt enable 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 piointen1 (r/w) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2046) 0 = interrupt disable 1 = interrupt enable pio0 pio7 pio8 pio0 pio7 pio8 figure 22. configuration of additional pio registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d these bits should always be written as shown.
admc326 C27C rev. c auxtm0 (r/w) 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 auxch1 (r/w) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2011) auxch0 (r/w) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2010) dm (0x2012) auxtm1 (r/w) 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2013) aux1 period = 2 (1 + auxtm1) t ck offset = 2 (1 + auxtm1) t ck t on, aux0 = 2 (auxch0) t ck t on, aux1 = 2 (auxch1) t ck aux0 period = 2 (auxtm0 + 1) t ck figure 23. configuration of aux registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d these bits should always be written as shown.
admc326 C28C rev. c 0 0 0 0 dm (0x2000) adc1 (r) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 0 0 dm (0x2001) adc2 (r) 151413121110987654 3210 0 0 0 0 dm (0x2002) adc3 (r) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 0 0 dm (0x2003) adcaux (r) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 dm (0x2068) iconst_trim (r/w) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 iconst min = bits 0 2 cleared. iconst max = bits 0 2 set. 0 0 0 00 0 0 00 0 0 00 0 0 0 figure 24. configuration of additional aux registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d these bits should always be written as shown.
admc326 C29C rev. c 0 = sport 1 = uart sport1 mode select 0 = dr1a 1 = dr1b sport1 data receive select 0 = disable 1 = enable pwmsync interrupt 0 = disable 1 = enable pwmtrip interrupt 0 0 0 0 0 0 00 0 0 0 sysstat (r) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 = low 1 = high dm (0x2016) 0 = normal 1 = watchdog reset occurred pwmtrip pin status watchdog status pwm timer status 0 = 1st half of pwm cycle 1 = 2nd half of pwm cycle 0 0 00 0 0 0 00 0 0 00 0 0 0 modectrl (r/w) dm (0x2015) 0 = single update mode 1 = double update mode 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 adc mux control 00 vaux0 01 vaux1 10 vaux2 11 vaux3 auxiliary pwm select 0 = offset mode 1 = independent mode adc counter select 0 = clkin rate 1 = clkout rate 0 0 00 0 0 0 00 0 0 0 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 00 irqflag (r) pwmtrip interrupt pwmsync interrupt dm (0x2017) 0 0 0 0 0 0 00 0 0 00 0 0 00 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 wdtimer (w) dm (0x2018) 01 0 = no interrupt 1 = interrupt occurred pwm update mode select figure 25. configuration of status registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d these bits should always be written as shown.
admc326 C30C rev. c sport1 receive or irq0 ifc interrupt force interrupt clear 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 timer software 0 software 1 irq2 timer software 0 irq2 dsp register 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 sport1 transmit or irq1 sport1 receive or irq0 sport1 transmit or irq1 0 0 0 0 0 irq0 sensitivity 0 = level 1 = edge icntl irq1 sensitivity irq2 sensitivity interrupt nesting 0 = disable 1 = enable dsp register 43210 imask (r/w) peripheral (or irq2 ) timer sport1 receive (or irq0 ) sport1 transmit (or irq1 ) software 0 software 1 0 0 0 0 0 0 0 00 0 0 00 0 0 0 dsp register 0 = disable (mask) 1 = enable 0 = disable (mask) 1 = enable 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 software 1 figure 26. configuration of interrupt control registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d these bits should always be written as shown.
admc326 C31C rev. c 1 1 1 1 1 1 1 11 1 1 11 1 1 1 dm (0x3ffe) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 memwait (r/w) 1 1 0 0 0 0 00 0 1 01 1 1 1 sport1 configure 0 = fi, fo, irq0, irq1, sclk 1 = serial port sport1 enable 0 = disabled 1 = enabled syscntl (r/w) dm (0x3fff) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 figure 27. configuration of registers default bit values are shown; if no value is shown, the bit field is undefined at reset. reserved bits are shown on a gray fiel d.
C32C c00104aC0C10/01(c) printed in u.s.a. admc326 rev. c outline dimensions dimensions shown in inches and (mm). 28-lead plastic dip (n-28) 0.195 (4.95) 0.125 (3.18) 0.015 (0.381) 0.008 (0.204) 0.625 (15.87) 0.600 (15.24) 28 114 15 pin 1 0.580 (14.73) 0.485 (12.32) 1.565 (39.70) 1.380 (35.10) seating plane 0.060 (1.52) 0.015 (0.38) 0.250 (6.35) max 0.022 (0.558) 0.014 (0.356) 0.200 (5.05) 0.125 (3.18) 0.150 (3.81) min 0.100 (2.54) bsc 0.070 (1.77) max 28-lead wide-body soic (r-28) seating plane 0.0118 (0.30) 0.0040 (0.10) 0.0192 (0.49) 0.0138 (0.35) 0.1043 (2.65) 0.0926 (2.35) 0.0500 (1.27) bsc 0.0125 (0.32) 0.0091 (0.23) 0.0500 (1.27) 0.0157 (0.40) 8 0 0.0291 (0.74) 0.0098 (0.25) x 45 0.7125 (18.10) 0.6969 (17.70) 0.4193 (10.65) 0.3937 (10.00) 0.2992 (7.60) 0.2914 (7.40) pin 1 28 15 14 1 revision history location page data sheet changed from rev. b to rev. c. edits to figure 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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