h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 375

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

Section 12 Watchdog Timer (WDT)
Section 12 Watchdog Timer (WDT)
This LSI has a two-channel watchdog timer (WDT_0, WDT_1). WDT is an 8-bit timer that can
generate an internal reset signal for this LSI if a system crash prevents the CPU from writing to
the timer counter, thus 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.
The block diagrams of the WDT_0 and WDT_1 are shown in figures 12.1 and 12.2, respectively.
12.1
Features
• Selectable from eight counter input clocks (WDT_0) or sixteen counter input clocks (WDT_1)
• Switchable between watchdog timer mode and interval timer mode
In watchdog timer mode:
• If the counter overflows, it is possible to select whether this LSI is internally reset or not or
whether an internal NMI interrupt is generated or not.
In interval timer mode:
• If the counter overflows, the WDT generates an interval timer interrupt (WOVI).
Rev. 2.00 Dec. 05, 2005 Page 337 of 724
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