WATCHDOG TIMER V1.1
Chapter 2 Watchdog Timer
MCU-AN-500013-E-11 – Page 5
2 Watchdog Timer
Basic function of the watchdog timer
2.1 Key Features
The watchdog timer functions as a counter used to prevent program from running out of
control. Once the watchdog timer is activated, its counter needs to be cleared at specified
intervals regularly. A watchdog reset is generated if the timer is not cleared within a preset
interval time base on chapter 3. The watchdog timer that is not cleared may be due to
problems in the program which has entered into an infinite loop or Stack over-run or other
possible problems that caused the CPU to hang.
The watchdog timer has the following features:
Count clock selector
Watchdog timer counter
Reset control circuit is used to generate the reset signal when the WDT counter
overflows
Watchdog timer clear selector is used to selects the watchdog timer clear signal
Counter timer control circuit
Hardware and software watchdog timer
2.2 Block Diagram
Figure 2-1 shows the internal block diagram of watchdog timer.
Figure 2-1: Block Diagram of Watchdog Timer
