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[Previous] [Up] [Top] [Contents] [Back]Chapter 3 Functional Description
The DS1232 MicroMonitor Chip monitors three vital conditions: power supply, software execution and external override.
When the power supply falls below 4.75 volts, the local processor is stopped by asserting the reset and halt inputs. On power-up, reset and halt are kept active for a minimum of 250 ms to allow the power supply and processor to stabilize.
The watchdog timer function forces reset and halt low to the processor when it is not stimulated for 600 ms. After a reset, the watchdog timer is initially stimulated by the ECLK of the processor. When the processor writes to the 'kick watchdog' location for the first time, the ECLK is removed from the watchdog timer and the local processor must write to the 'kick watchdog' location every 600 ms to prevent the watchdog timer from resetting the processor.
An external override is generated via the mailbox reset function. The reset and halt signals to the processor are asserted for a period of 250 ms after a write to the mailbox reset locations.
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