HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 433

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

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.
Note:
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
signal when TCNT overflows.
Note:
Bit 5—Timer Enable (TME): Selects whether TCNT runs or is halted.
Bits 4 and 3—Reserved: Read-only bits, always read as 1.
Bit 7
OVF
0
1
Bit 6
WT/IT IT IT IT
0
1
Bit 5
TME
0
1
* When OVF is polled and the interval timer interrupt is disabled, OVF = 1 must be read
* For details of the case where TCNT overflows in watchdog timer mode, see section
at least twice.
11.2.3, Reset Control/Status Register (RSTCSR).
Description
[Clearing condition]
Cleared by reading TCSR when OVF = 1, then writing 0 to OVF*
[Setting condition]
Set when TCNT overflows (changes from H'FF to H'00) in interval timer mode
Description
Interval timer: Sends the CPU an interval timer interrupt request (WOVI)
when TCNT overflows
Watchdog timer: Generates the WDTOVF signal when TCNT overflows*
Description
TCNT is initialized to H'00 and halted
TCNT counts
Rev.3.00 Mar. 26, 2007 Page 391 of 772
Section 11 Watchdog Timer
REJ09B0355-0300
(Initial value)
(Initial value)
(Initial value)