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CHAPTER 9 WATCHDOG TIMER
User’s Manual U13850EJ6V0UD
264
(3) Watchdog timer mode register (WDTM)
This register sets the operating mode of the watchdog timer, and enables and disables counting.
WDTM is set by an 8-bit or 1-bit memory manipulation instruction.
RESET input clears WDTM to 00H.
After reset: 00H
R/W
Address: FFFFF384H
<7>
6
5
4
3
2
1
0
WDTM
RUN
0
0
WDTM4
0
0
0
0
RUN
Operating mode selection for the watchdog timer
Note 1
0
Disable count
1
Clear count and start counting
WDTM4
Operating mode selection for the watchdog timer
Note 2
0
Interval timer mode
(If an overflow occurs, the maskable interrupt INTWDTM is generated.)
1
Watchdog timer mode 1
(If an overflow occurs, the non-maskable interrupt INTWDT is generated.)
Notes 1.
Once RUN is set (1), the register cannot be cleared (0) by software. Therefore, when counting starts,
counting cannot be stopped except by RESET input.
2.
Once WDTM4 is set (1), the register cannot be cleared (0) by software.
Caution
If RUN is set (1) and the watchdog timer is cleared, the actual overflow time may be up to 2
10
/f
XX
seconds shorter than the set time.