Table of Contents
Advertisement
WATCHDOG
Unless it is cleared every 64K state times, the watchdog timer resets the device. To clear the
watchdog timer, send "1EH" followed immediately by "E1H" to location 0AH. Clearing this register the
first time enables the watchdog with an initial value of 0000H, which is incremented once every state
time. After it is enabled, the watchdog can be disabled only by a reset.
The WDE bit (bit 3) of CCR1 controls whether the watchdog is enabled immediately or is disabled until
the first time it is cleared. Clearing WDE activates the watchdog. Setting WDE makes the watchdog
timer inactive, but you can activate it by clearing the watchdog register. Once the watchdog is
activated, only a reset can disable it.
7
Bit
Number
7:0
Watchdog Timer Value
This register contains the 8 most-significant bits of the current value of the watchdog
timer.
Watchdog Timer Value
Function
REGISTERS
WATCHDOG
Address:
0AH
Reset State:
00H
0
C-79
Advertisement
Table of Contents
