
72
CHAPTER 4 APPLICATIONS OF WATCHDOG TIMER
Figure 4-3. Format of Watchdog Timer Clock Select Register
(
μ
PD780024, 780024Y, 780034, 780034Y, 780924, 780964 subseries)
WDCS2 WDCS1 WDCS0
Overflow time of watchdog timer/interval timer
0
0
0
2
12
/f
X
(489
μ
s)
0
0
1
2
13
/f
X
(978
μ
s)
0
1
0
2
14
/f
X
(1.96 ms)
0
1
1
2
14
/f
X
(3.91 ms)
1
0
0
2
16
/f
X
(7.82 ms)
1
0
1
2
17
/f
X
(15.6 ms)
1
1
0
2
18
/f
X
(31.3 ms)
1
1
1
2
20
/f
X
(125 ms)
Remarks 1.
f
XX
: main system clock oscillation frequency
2.
( ) : f
X
= 8.38 MHz
7
0
6
0
5
0
4
0
3
0
2
WDCS2
1
WDCS1
0
WDCS0
Symbol
WDCS
Address
FF42H
At reset
00H
R/W
R/W