UPD78F0988AGC-8BS Renesas Electronics America, UPD78F0988AGC-8BS Datasheet - Page 181

• Manufacturer Part Number: UPD78F0988AGC-8BS
• Manufacturer: Renesas Electronics America

Specifications of UPD78F0988AGC-8BS

• Lead Free Status / Rohs Status: Supplier Unconfirmed

9.5.2 Operation as interval timer
an interval timer that repeatedly generates an interrupt request at time intervals specified by a preset count value.
time of interval timer. When bit 7 (RUN) of WDTM is set to 1, the watchdog timer starts operating as an interval timer.
a maskable interrupt request (INTWDT) can be generated. The default priority of INTWDT is set as the highest of
all the maskable interrupt requests.
1 before entering the STOP mode to clear the interval timer, and then execute the STOP instruction.
When bit 4 (WDTM4) of the watchdog timer mode register (WDTM) is set to 0, the watchdog timer operates as
Bits 0 to 2 (WDCS0 to WDCS2) of the watchdog timer clock select register (WDCS) can be used to select the interval
In the interval timer mode, the interrupt mask flag (WDTMK) and priority specification flag (WDTPR) are valid, and
The interval timer continues operation in the HALT mode, but stops in the STOP mode. Therefore, set RUN to
Cautions 1. Once bit 4 (WDTM4) of WDTM has been set to 1 (when the watchdog timer mode is
Note Expanded-specification products only.
Remark f
WDCS2 WDCS1 WDCS0
0
0
0
0
1
1
1
1
2. The interval time immediately after it has been set by WDTM may be up to 2
X
: System clock oscillation frequency
selected), the interval timer mode is not set, unless the RESET signal is input.
shorter than the set time.
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Table 9-5. Interval Time of Interval Timer
CHAPTER 9 WATCHDOG TIMER
Interval Time
2
2
2
2
2
2
2
2
12
13
14
15
16
17
18
20
User’s Manual U13029EJ7V1UD
1/f
1/f
1/f
1/f
1/f
1/f
1/f
1/f
X
X
X
X
X
X
X
X
At f
X
= 12 MHz
341.3 s
682.6 s
1.36 ms
2.73 ms
5.46 ms
10.9 ms
21.8 ms
87.3 ms
Note
At f
125.1 ms
488.8 s
977.6 s
X
1.96 ms
3.91 ms
7.82 ms
15.6 ms
31.3 ms
= 8.38 MHz
8
/f
X
seconds
179