beautypg.com

1 overview of watchdog timer, Overview of watchdog timer – FUJITSU F2MCTM-16LX User Manual

Page 212

background image

196

CHAPTER 12 WATCHDOG TIMER

12.1

Overview of Watchdog Timer

The watchdog timer is a 2-bit counter that uses the timebase timer or watch timer as a
count clock. If the counter is not cleared within a set interval time, the CPU is reset.

Functions of Watchdog Timer

The watchdog timer is a timer counter that is used to prevent program malfunction. When the watchdog

timer is started, the watchdog timer counter must continue to be cleared within a set interval time. If the

set interval time is reached without clearing the watchdog timer counter, the CPU is reset. This is called

watchdog timer.

The interval time of the watchdog timer depends on the clock cycle input as a count clock and a

watchdog reset occurs between the minimum and maximum times.

The clock source output destination is set by the watchdog clock select bit in the watch timer control

register (WTC: WDCS).

The interval time of the watchdog timer is set by the timebase timer output select bit/watch timer output

select bit in the watchdog timer control register (WDTC: WT1, WT0).

Table 12.1-1 lists the interval times of the watchdog timer.