Renesas H8S/2319 series Hardware Manual page 441

Bit 7—Overflow Flag (OVF): Indicates that TCNT has overflowed from H'FF to H'00, when in
interval timer mode. This flag cannot be set during watchdog timer operation.
Bit 7
OVF Description
0 [Clearing condition]
Cleared by reading TCSR when OVF = 1 * , then writing 0 to OVF
1 [Setting condition]
Set when TCNT overflows (changes from H'FF to H'00) in interval timer mode
Note: * When OVF is polled and the interval timer interrupt is disabled, OVF = 1 must be read at
least twice.
Bit 6—Timer Mode Select (WT/IT IT IT IT): Selects whether the WDT is used as a watchdog timer or
interval timer. If used as an interval timer, the WDT generates an interval timer interrupt request
(WOVI) when TCNT overflows. If used as a watchdog timer, the WDT generates the WDTOVF
1
signal *
when TCNT overflows.
Bit 6
WT/IT IT IT IT
Description
0 Interval timer: Sends the CPU an interval timer interrupt request (WOVI)
when TCNT overflows
Watchdog timer: Generates the WDTOVF signal *
1
Notes: 1. The WDTOVF function is not available in the F-ZTAT versions.
2. For details of the case where TCNT overflows in watchdog timer mode, see section
11.2.3, Reset Control/Status Register (RSTCSR).
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 counts
Bits 4 and 3—Reserved: These bits cannot be modified and are always read as 1.
1
when TCNT overflows *
Rev. 5.00, 12/03, page 411 of 1088
(Initial value)
(Initial value)
2
(Initial value)