Structure Of Watchdog Timer; Figure 6.2-1 Block Diagram Of Watchdog Timer - Fujitsu F2MC-8L Series Hardware Manual

6.2

Structure of Watchdog Timer

The watchdog timer consists of the following six blocks:
• Count clock selector
• Watchdog timer counter
• Reset controller
• Watchdog timer clear selector
• Counter clear controller
• Watchdog timer control register (WDTC)
Block Diagram of Watchdog Timer
2 22 /F
CH
(Timebase timer output)
2 14 /F
CL
(Watch prescaler output)
Clear signal from
timebase timer
Clear signal from
watch prescaler
Start sleep mode
Start stop mode
Start watch mode
F : Main clock oscillation
CH
F : Subclock oscillation
CL
Count clock selector
Selects the count clock for the watchdog timer counter. The count clock can be the timebase
timer or watch prescaler output.
Watchdog timer counter (1-bit counter)
A 1-bit counter that uses either output from the timebase timer or from the watch prescaler as a
count clock

Figure 6.2-1 Block Diagram of Watchdog Timer

Watchdog control register (WDTC)
CS – – –
Count clock
selector
Watchdog timer
clear selector
6.2 Structure of Watchdog Timer
WTE3 WTE2 WTE1 WTE0
Watchdog timer
Clear Activate
Overflow
1-bit counter
Counter clear
controller
RST
Reset controller
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