Single-Chip Microcontrollers User's Manual

247
CHAPTER 11 WATCHDOG TIMER
Prescaler
f XX
2
4
f XX
2
5
f XX
2
6
f XX
2
7
f XX
2
8
f XX
2
9
Selector
Watchdog Timer Mode Register
Internal Bus
Internal Bus
TCL22 TCL21
TCL20
f XX /2
3
f XX
2
11
Timer Clock Select Register 2
3
WDTM4RUN
WDTM3
8-Bit Counter
TMMK4
RUN
TMIF4
INTWDT
Maskable
Interrupt
Request
INTWDT
Non-Maskable
Interrupt
Request
RESET
Control
Circuit
11.2 Watchdog Timer Configuration
The watchdog timer consists of the following hardware.
Table 11-3. Watchdog Timer Configuration
Item Configuration
Timer clock select register 2 (TCL2)
Watchdog timer mode control register (WDTM)
Figure 11-1. Watchdog Timer Block Diagram
Control register