ds1232 pdf datasheet (MicroMon

The DS1232 MicroMonitor Chip monitors three vital
conditions for a microprocessor: power supply, software
execution, and external override. First, a precision temperature-
compensated reference and comparator circuit
monitors the status of VCC. When an out-of-tolerance
condition occurs, an internal power fail signal is
generated which forces reset to the active state. When
VCC returns to an in-tolerance condition, the reset signals
are kept in the active state for a minimum of 250 ms
to allow the power supply and processor to stabilize.
The second function the DS1232 performs is pushbutton
reset control. The DS1232 debounces the pushbutton
input and guarantees an active reset pulse width of
250 ms minimum. The third function is a watchdog timer.
The DS1232 has an internal timer that forces the reset
signals to the active state if the strobe input is not driven
low prior to time-out. The watchdog timer function can
be set to operate on time-out settings of approximately
150 ms, 600 ms, and 1.2 seconds.