Action
Start and stop the watchdog timer.
Syntax
START WATCHDOG 'will start the watchdog timer.
STOP WATCHDOG 'will stop the watchdog timer.
RESET WATCHDOG 'will reset the watchdog timer.
Remarks
The AT89S8252 has a built in watchdog timer.
A watchdog timer is a timer that will reset the uP when it reaches a certain value.
So during program execution this WD-timer must be reset before it exceeds its maximum value. This is used to be sure a program is running correct.
When a program crashes or sits in an endless loop it will not reset the WD-timer so an automatic reset will occur resulting in a restart.
You need to configure the reset time with CONFIG WATCHDOG.
CONFIG WATCHDOG = value
value |
The time in mS it takes the WD will overflow, causing a reset. Possible values are : 16,32,64,128,256,512,1024 or 2048 |
See Also
Example
DIM A AS INTEGER
CONFIG WATCHDOG = 2048 'after 2 seconds a reset will occur
START WATCHDOG 'start the WD
DO
PRINT a
a = a + 1 'notice the reset
REM RESET WATCHDOG 'delete the REM to run properly
LOOP
END