8XC196MC, MD, MH USER’S MANUAL

WATCHDOG

WATCHDOG

Address:

0AH

 

Reset State:

XXH

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

0

 

Watchdog Timer Value

 

 

Bit

Function

Number

 

 

 

7:0

Watchdog Timer Value

 

This register contains the 8 most-significant bits of the current value of the watchdog

 

timer.

 

 

C-58

Page 535
Image 535
Intel 8XC196MH, 8XC196MD, 8XC196MC manual Watchdog, 0AH