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Appendix 1 - Watch Dog Timer
Stingray II+ User's Guide
A1-1
Watch Dog Timer
Watch Dog Timer Working Procedure
The Watch Dog Timer (WDT) is a special hardware device whose funcĆ
tion is to monitor whether the computer system is working normally. If
not, it will have some measures to correct the problem.
It contains a receivable SQW signal from RTC, and could set time and
can clear the counter function. When time is up, WDT can send Reset or
NMI signal.
Operator has to write a value into WDT Configuration Register (Write the
control value to the Configuration Port), and clear WDT counter (read the
Configuration Port).
Watch Dog Timer character and function
WDT Configuration port F2 Default at F2
Watch Dog Timer Disabled 1. Default at disabled
Enabled
2. Enabled for user
′
s programming
WDT Time out active for Reset Default at Reset
NMI
WDT Active Time 1 sec
2 sec
4 sec
8 sec
16 sec
32 sec
64 sec
Default at 64 sec