M38203M4 Datasheet, PDF (261/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.8 Watchdog timer
2.8.2 Related register
The related register is only the watchdog timer control register (address 003716).
The operation of the watchdog timer is started by executing a write instruction to the watchdog timer control
register after reset. The watchdog timer being operated is made ineffective by reset.
When the watchdog timer is not used, do not execute a write instruction to the watchdog timer control
register after reset.
Figure 2.8.2 shows the structure of the watchdog timer control register.
Watchdog timer control register
b7 b6 b5 b4 b3 b2 b1 b0
Watchdog timer control register (WDTCON) [Address 3716]
B
Name
0 ^{Watchdog timer H}
to ^bits
5
Functions
At reading, the count value of
watchdog timer H is read.
6 Nothing is allocated. This bit cannot be written to and
is fixed to “1” at reading.
At reset R W
1
×
(Note)
1 1^×
7 ^{Watchdog timer H} _{0: Underflow from watchdog}
0
count source
timer L
selection bit
(WDT is used as 14-bit timer)
1: f(XIN)/16 or f(XCIN)/16
(WDT is used as 6-bit timer)
Note: When a value is written to address 3716, the following values are set,
so that the watchdog timer starts a count operation.
Watchdog timer H = “3F16”
Watchdog timer L = “FF16”
Fig. 2.8.2 Structure of watchdog timer control register
3820 GROUP USER’S MANUAL
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