CHAPTER 10 WATCHDOG TIMER
User’s Manual U16899EJ2V0UD
233
10.2 Configuration of Watchdog Timer
The watchdog timer includes following hardware.
Table 10-3. Configuration of Watchdog Timer
Item Configuration
Control registers
Watchdog timer mode register (WDTM)
Watchdog timer enable register (WDTE)
Figure 10-1. Block Diagram of Watchdog Timer
f
R
/2
2
Clock
input
controller
Output
controller
Internal reset signal
WDCS2
Internal bus
WDCS1 WDCS0
f
XP
/2
4
WDCS3
WDCS4
0
1
1
Selector
16-bit
counter
or
2
13
/f
XP
to
2
20
/f
XP
2
11
/f
R
to
2
18
/f
R
Watchdog timer enable
register (WDTE)
Watchdog timer mode
register (WDTM)
3
2
Clear
Option byte
(to set “Ring-OSC
cannot be stopped” or
“Ring-OSC can be
stopped by software”)