Panasonic MN101C77C, F77G user manual IX 6 Operation

Chapter 9 Watchdog Timer

„Watchdog Timer and CPU Mode

The relation between this watchdog timer and CPU mode features are as follows ;

(1)In NORMAL, IDLE, SLOW mode, the system clock is counted.

(2)The counting is continued regardless of switching at NORMAL, IDLE, SLOW mode.

(3)In HALT mode, the watchdog timer is stopped.

(4)In STOP mode, the watchdog timer is cleared automatically by hardware.

(5)In STOP mode, the watchdog interrupt cannot be generated.

(6)After releasing reset or recovering from STOP, the counting is executed for the duration of the oscillation stabilization wait time.

Generally, in the system used STOP mode, if the STOP mode is done or not is divided on the program execution, but, in this case, the counting value of the watchdog timer differs. So, the watchdog interrupt should be prevented by setting the lowest value for watchdog timer clear.

IX - 6 Operation