Datasheet

Section 14 Watchdog Timer
Rev. 3.00 Mar 17, 2006 page 652 of 926
REJ09B0283-0300
Bit Bit Name Initial Value R/W Description
4, 3 — All 1 — Reserved
These bits are always read as 1 and cannot be
modified.
2
1
0
CKS2
CKS1
CKS0
0
0
0
R/W
R/W
R/W
Clock Select 2 to 0
Selects the clock source to be input to TCNT. The
overflow frequency for φ = 20 MHz is enclosed in
parentheses.
000: Clock φ/2 (frequency: 25.6 µs)
001: Clock φ/64 (frequency: 819.2 µs)
010: Clock φ/128 (frequency: 1.6 ms)
011: Clock φ/512 (frequency: 6.6 ms)
100: Clock φ/2048 (frequency: 26.2 ms)
101: Clock φ/8192 (frequency: 104.9 ms)
110: Clock φ/32768 (frequency: 419.4 ms)
111: Clock φ/131072 (frequency: 1.68 s)
Note: * Only a write of 0 is permitted, to clear the flag.