m5m51016btp Renesas Electronics Corporation., m5m51016btp Datasheet - Page 265

• Manufacturer Part Number: m5m51016btp
• Description: Renesas 16-bit Single-chip Microcomputer M16c Family / M16c/20 Series
• Manufacturer: Renesas Electronics Corporation.

M30245 Group
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
Operation
Figure 2.12.3. Operation timing of watchdog timer (watchdog timer interrupt)
2.12.2 Operation of Watchdog Timer (Watchdog timer interrupt)
The following is an operation of the watchdog timer using watchdog timer interrupt. Figure 2.12.3 shows
the operation timing, and Figure 2.12.4 shows the set-up procedure.
Write signal to the
watchdog timer
start register
(1) Writing to the watchdog timer start register initializes the watchdog timer to 7FFF
(2) With a count in progress, writing to the watchdog timer start register again initializes the
(3) Either executing the WAIT instruction or going to the stopped state causes the watchdog
(4) If the watchdog timer underflows, it is initialized to 7FFF
7FFF
0000
causes it to start a down count.
watchdog timer to 7FFF
timer to hold the count in progress and to stop counting. The watchdog timer resumes count-
ing after returning from the execution of the WAIT instruction or from the stopped state.
time, a watchdog timer interrupt occurs.
“H”
“L”
16
16
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(1) Start count
16
and causes it to resume counting.
(2) Write operation
(3) In stopped state, or WAIT
instruction is executing, etc
16
and continues counting. At this
(4) Generate
watchdog timer
interrupt
2. Watchdog Timer
16
and