User’s Manual U13850EJ4V0UM
230
CHAPTER 8 WATCH TIMER
8.1 Function
The watch timer has the following functions:
• Watch timer
• Interval timer
The watch timer and interval timer functions can be used at the same time.
Figure 8-1. Block Diagram of Watch Timer
f
W
/2
10
Se
le
ct
or
11-bit prescaler
f
W
/2
8
f
W
/2
7
f
W
/2
6
f
W
/2
5
f
W
/2
4
5-bit counter
INTWTN
INTWTNI
WTNM0
WTNM1
WTNM3
WTNM4
WTNM5
WTNM6
WTNM7
Watch timer mode control
register (WTNM)
f
XX
Internal bus
Clear
Clear
WTNM2
f
XT
f
W
/2
9
f
W
/2
11
WTNCS1 WTNCS0
Se
le
ct
or
Se
le
ct
or
Se
le
ct
or
Watch timer clock selection
register (WTNCS)
3
f
W
Remark
f
XX
: Main system clock frequency
f
XT
: Subsystem clock frequency
f
W
:
Watch timer clock frequency
