Datasheet

Section 15 Watchdog Timer
(WDT1 is not available in the H8S/2695)
R01UH0166EJ0600 Rev. 6.00 Page 721 of 1434
Mar 02, 2011
H8S/2633 Group, H8S/2633 F-ZTAT
TM
,
H8S/2633R F-ZTAT
TM
, H8S/2695
15.4 Interrupts
During interval timer mode operation, an overflow generates an interval timer interrupt (WOVI).
The interval timer interrupt is requested whenever the OVF flag is set to 1 in TCSR. OVF must be
cleared to 0 in the interrupt handling routine.
If an NMI request has been chosen in the watchdog timer mode, an NMI request is generated
when a TCNT overflow occurs.
15.5 Usage Notes
15.5.1 Contention between Timer Counter (TCNT) Write and Increment
If a timer counter clock pulse is generated during the T
2
state of a TCNT write cycle, the write
takes priority and the timer counter is not incremented. Figure 15.8 shows this operation.
Address
φ
Internal write signal
TCNT input clock
TCNT
NM
T
1
T
2
TCNT write cycle
Counter write data
Figure 15.8 Contention between TCNT Write and Increment