upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 218

• Manufacturer Part Number: upd70f3017ay
• Description: V850/sa1tm 32-/16-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

9.4 Operation
9.4.1 Operating as watchdog timer
program loop.
the set time interval for loop detection, the watchdog timer is cleared and counting starts again.
(no reset function).
clear the watchdog timer before entering the IDLE mode or software STOP mode. Do not set the watchdog timer
when operating in the HALT mode since the watchdog timer runs in HALT mode.
218
Set bit 4 (WDTM4) of the watchdog timer mode register (WDTM) to 1 to operate as a watchdog timer to detect a
Setting bit 7 (RUN) of WDTM to 1 starts the count operation. After counting starts, if RUN is set to 1 again within
If RUN is not set to 1 and the loop detection time has elapsed, a non-maskable interrupt (INTWDT) is generated
The watchdog timer stops running in the IDLE mode and software STOP mode. Consequently, set RUN to 1 and
Cautions 1. The actual loop detection time can be up to 2
2. When the subclock is selected as the CPU clock, the watchdog timer stops (suspends)
counting.
2
2
2
2
2
2
2
2
14
15
16
17
18
19
20
22
/f
/f
/f
/f
/f
/f
/f
/f
XX
XX
XX
XX
XX
XX
XX
XX
Clock
Table 9-4. Loop Detection Time of Watchdog Timer
819.2
1.6 ms
3.3 ms
6.6 ms
13.1 ms
26.2 ms
52.4 ms
209.7 ms
f
XX
= 20 MHz
CHAPTER 9
µ
s
User’s Manual U12768EJ4V1UD
964
1.928 ms
3.855 ms
7.710 ms
15.42 ms
30.84 ms
61.68 ms
246.7 ms
f
XX
WATCHDOG TIMER
= 17 MHz
µ
s
Loop Detection Time
10
/f
XX
1.6 ms
3.2 ms
6.6 ms
13.1 ms
26.2 ms
52.4 ms
104.9 ms
419.4 ms
f
XX
[seconds] shorter than the set time.
= 10 MHz
8.2 ms
16.4 ms
32.8 ms
65.5 ms
131.1 ms
262.1 ms
524.3 ms
2.1 s
f
XX
= 2 MHz