h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 445

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

12.1
The H8S/2646 Group has an on-chip watchdog timer with two channels (WDT0, WDT1). The
WDT can also generate an internal reset signal for the H8S/2646 Group if a system crash prevents
the CPU from writing to the timer counter, allowing it to overflow.
When this watchdog function is not needed, the WDT can be used as an interval timer. In interval
timer operation, an interval timer interrupt is generated each time the counter overflows.
12.1.1
WDT features are listed below.
• Switchable between watchdog timer mode and interval timer mode
• An internal reset can be issued if the timer counter overflows.
• Interrupt generation when in interval timer mode
• WDT0 and WDT1 respectively allow eight and sixteen types of counter input clock to be
In the watchdog timer mode, the WDT can generate an internal reset.
If the counter overflows, the WDT generates an interval timer interrupt.
selected
The maximum interval of the WDT is given as a system clock cycle × 131072 × 256.
A subclock may be selected for the input counter of WDT1.
Where a subclock is selected, the maximum interval is given as a subclock cycle × 256 × 256.
Overview
Features
Section 12 Watchdog Timer
Rev. 5.00 Sep 22, 2005 page 419 of 1136
Section 12 Watchdog Timer
REJ09B0257-0500