upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 219

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

9.4.2 Operating as interval timer
timer that repeatedly generates interrupts with a preset count value as the interval.
setting flag (WDTPR0 to WDTPR2) become valid, and a maskable interrupt (INTWDTM) can be generated. The
default priority of INTWDTM has the highest priority setting of the maskable interrupts.
Therefore, before entering the IDLE mode/software STOP mode, set the RUN bit of WDTM register to 1 and clear the
interval timer. Then set the IDLE mode/software STOP mode.
Set bit 4 (WDTM4) to 0 in the watchdog timer mode register (WDTM) to operate the watchdog timer as an interval
When operating as an interval timer, the interrupt mask flag (WDTMK) of the WDTIC register and the priority
The interval timer continues operating in the HALT mode and stops in the IDLE mode and software STOP mode.
Cautions 1. Once bit 4 (WDTM4) of WDTM is set to 1 (selecting the watchdog timer mode), the interval
2. The interval time immediately after setting in WDTM can be up to 2
3. When the subclock is selected as the CPU clock, the watchdog timer stops (suspends)
timer mode is not entered as long as RESET is not input.
than the set time.
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
819.2
1.6 ms
3.3 ms
6.6 ms
13.1 ms
26.2 ms
52.4 ms
209.7 ms
Table 9-5. Interval Time of Interval Timer
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
= 17 MHz
WATCHDOG TIMER
µ
s
Interval Time
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
= 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
10
/f
XX
[seconds] shorter
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