D12320VF25V Datasheet, PDF (459/1146 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 11 Watchdog Timer
11.3.2 Operation in Interval Timer Mode
To use the WDT as an interval timer, clear the WT/IT bit in TCSR to 0 and set the TME bit to 1.
An interval timer interrupt (WOVI) is generated each time TCNT overflows, provided that the
WDT is operating as an interval timer, as shown in figure 11.5. This function can be used to
generate interrupt requests at regular intervals.
TCNT count
H'FF
Overflow
Overflow
Overflow
Overflow
H'00
WT/IT=0
TME=1
WOVI
WOVI
Legend
WOVI: Interval timer interrupt request generation
WOVI
WOVI
Time
Figure 11.5 Operation in Interval Timer Mode
Rev.7.00 Feb. 14, 2007 page 425 of 1108
REJ09B0089-0700