h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 387

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

12.5.5
This LSI is not reset internally if TCNT overflows while the RSTE bit is cleared to 0 during
watchdog timer operation, however TCNT and TCSR of the WDT are reset.
TCNT, TCSR, or RSTCR cannot be written to for 132 states following an overflow. During this
period, any attempt to read the WOVF flag is not acknowledged. Accordingly, wait 132 states
after overflow to write 0 to the WOVF flag for clearing.
12.5.6
When the OVF flag setting conflicts with the OVF flag reading in interval timer mode, writing 0
to the OVF bit may not clear the flag even though the OVF bit has been read while it is 1. If there
is a possibility that the OVF flag setting and reading will conflict, such as when the OVF flag is
polled with the interval timer interrupt disabled, read the OVF bit while it is 1 at least twice before
writing 0 to the OVF bit to clear the flag.
Internal Reset in Watchdog Timer Mode
OVF Flag Clearing in Interval Timer Mode
Rev. 2.00 Dec. 05, 2005 Page 349 of 724
Section 12 Watchdog Timer (WDT)
REJ09B0200-0200