Hitachi F-ZTAT H8/3039 Series Hardware Manual page 326

Bit 7—Overflow Flag (OVF): This status flag indicates that the timer counter has overflowed
from H'FF to H'00.
Bit 7
OVF Description
0 [Clearing condition]
Cleared by reading OVF when OVF = 1, then writing 0 in OVF
1 [Setting condition]
Set when TCNT changes from H'FF to H'00
Bit 6—Timer Mode Select (WT/IT): Selects whether to use the WDT as a watchdog timer or
interval timer. If used as an interval timer, the WDT generates an interval timer interrupt request
when TCNT overflows. If used as a watchdog timer, the WDT generates a reset signal when
TCNT overflows.
Bit 6
WT/IT Description
0 Interval timer: requests interval timer interrupts
1 Watchdog timer: generates a reset signal
Bit 5—Timer Enable (TME): Selects whether TCNT runs or is halted.
Bit 5
TME Description
0 TCNT is initialized to H'00 and halted
1 TCNT is counting
Bits 4 and 3—Reserved: These bits cannot be modified and are always read as 1.
316
(Initial value)
(Initial value)
(Initial value)