Overview - Fujitsu F2MC-16LX Hardware Manual

CHAPTER 11 WATCH TIMER

11.1 Overview

The watch timer is a 15-bit timer using the sub-clock. This timer can generate interval
interrupts. Furthermore, depending on the setting, this timer can be used as the clock
source for the watchdog timer.
I Functions of watch timer
The watch timer is composed of a 15-bit timer and a circuit to control interval interrupts.
The watch timer uses the sub-clock regardless of the PLL clock selection bit (MCS) or the sub-
clock selection bit (SCS) in the clock selection register (CKSCR).
Table 11.1-1 "Interval times of watch timer" lists the interval times of the watch timer.
Table 11.1-1 Interval times of watch timer
WTC2
0
0
0
0
1
1
1
1
*1: Sub-clock: 32 kHz frequency divided by 4 (= 8 KHz)
216
WTC1 WTC0
0 0
0 1
1 0
1 1
0 0
0 1
1 0
1 1 Setting is prohibited
Interval time (*1)
31.25 ms
62.5 ms
125 ms
250 ms
500 ms
1.000 s
2.000 s