SH7065 Datasheet, PDF (527/941 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7000 Series

Section 13 Watchdog Timer
Section 13 Watchdog Timer
13.1 Overview
The SH7065 has a single-channel on-chip watchdog timer (WDT) for monitoring system
operation. The WDT outputs an overflow signal (WDTOVF) externally if a system crash prevents
the CPU from writing to the timer counter, allowing it to overflow. At the same time, the WDT
can also generate an internal reset signal for the SH7065.
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 requested each time the counter overflows. The WDT
is also in exiting software standby mode.
13.1.1 Features
The WDT has the following features:
• Switchable between watchdog timer mode and interval timer mode
• WDTOVF output when in watchdog timer mode
If the counter overflows, the WDT outputs WDTOVF externally. It is possible to select
whether or not the SH7065 is reset internally at the same time.
• Interrupt generation when in interval timer mode
If the counter overflows, the WDT generates an interval timer interrupt.
• Used when exiting software standby mode
• Choice of eight counter input clocks
Rev. 5.00 Sep 11, 2006 page 505 of 916
REJ09B0332-0500