Rev. 1.0, 02/00, page 357 of 1141
17.3.3
Timing of Setting of Overflow Flag (OVF)
The OVF bit in WTCSR is set to 1 if WTCNT overflows during interval timer operation. At the
same time, an interval timer interrupt (WOVI) is requested. This timing is shown in figure 17.5.
If NMI request generation is selected in watchdog timer mode, when WTCNT overflows the OVF
bit in WTCSR is set to 1 and at the same time an NMI interrupt is requested.
CK
WTCNT
H'FF
H'00
Overflow signal
(internal signal)
OVF
Figure 17.5 Timing of OVF Setting