CHAPTER 8 WATCH TIMER
User’s Manual U13850EJ4V0UM
233
Remarks 1.
f
W
: Watch timer clock frequency
2.
Values in parentheses apply when f
W
= 32.768 kHz.
3.
For the settings of WTNM7, refer to
Figure 8-3
.
(2) Watch timer clock selection register (WTNCS)
This register selects the count clock of the watch timer.
WTNCS is set using an 8-bit memory manipulation instruction.
RESET input clears WTNCS to 00H.
Caution Do not change the count clock during a watch timer operation.
Figure 8-3. Watch Timer Clock Selection Register (WTNCS)
After reset: 00H
R/W
Address: FFFFF364H
7
6
5
4
3
2
1
0
WTNCS
0
0
0
0
0
0
WTNCS1 WTNCS0
WTNCS1
WTNCS0
WTNM7
Selection of count clock
Main clock frequency
0
0
0
f
XX
/2
7
4.194 MHz
0
0
1
f
XT
(sub clock)
–
0
1
0
f
XX
/3
×
2
6
6.291 MHz
0
1
1
f
XX
/2
8
8.388 MHz
1
0
0
Setting prohibited
–
1
0
1
Setting prohibited
–
1
1
0
f
XX
/3
×
2
7
12.582 MHz
1
1
1
f
XX
/2
9
16.776 MHz
Note
Note
Only for the V850/SB1.
Remark
WTNM7 is bit 7 of the WTNM register