r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 846

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Section 14 Watchdog Timer (WDT)
Note:
Rev. 1.00 Sep. 19, 2008 Page 816 of 1342
REJ09B0467-0100
Bit
6
5
4, 3
2
1
0
Bit Name
WT/IT
TME
—
CKS2
CKS1
CKS0
*
Only a write of 0 is permitted, to clear the flag.
0
Initial Value
0
All 1
0
0
0
R/W
R/W
R/W
—
R/W
R/W
R/W
Timer Enable
Description
Timer Mode Select
Selects whether the WDT is used as a watchdog
timer or interval timer.
0: Interval timer mode
When TCNT overflows, an interval timer interrupt
(WOVI) is requested.
1: Watchdog timer mode
When TCNT overflows, the WDTOVF signal is
output.
When this bit is set to 1, TCNT starts counting.
When this bit is cleared, TCNT stops counting and
is initialized to H'00.
Reserved
These bits are always read as 1 and cannot be
modified.
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)