DS1830 programmable micromonitor DS1830 product preview 022698 1/1 features ? halts and restarts an outofcontrol microprocessor ? holds microprocessor in check during power tran- sients ? automatically restarts microprocessor after power failure ? monitors pushbutton for external override ? major function parameters programmable through simple 3wire interface, stored in nonvolatile memory ? reset time programmable from 5 ms to 2.5 seconds ? watchdog timeout programmable from 25 ms to 12.5 seconds ? power trip points programmable 4.75v to 2.7v ? pin compatible with the ds1232 ? low cost 8pin dip and 8pin soic packages avail- able ? operating temperature of 40 c to +85 c pin assignment gnd v cc clk cs pbrst rst st rst/dq 1 2 3 4 8 7 6 5 1 2 3 4 8 7 6 5 gnd clk cs pbrst v cc rst st rst/dq DS1830 8pin soic (150 mil) DS1830 8pin dip (300 mil) see mech. drawing pg. 480 see mech. drawing pg. 483 pin description pbrst pushbutton reset input cs chip select for serial port clk clock for serial port gnd ground rst/dq active high reset output/serial data input rst active low reset output st strobe input v cc power supply description the DS1830 programmable micromonitor monitors three vital conditions for a microprocessor: power sup- ply, software execution, and external override. all moni- tored parameters are programmable, with values stored in nonvolatile eprom. this allows parameters such as reset time, watchdog timeout period, and power supply tolerance to be programmed into the device and tailored to the application circuit and microprocessor which is to be monitored. in addition, the watchdog timer, reset, and pushbutton functions may be disabled via software. this allows maximum flexibility for use in new product development and system application testing.
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