Section 13 Watchdog Timer (WDT)
Rev. 2.00 Mar 09, 2006 page 543 of 906
REJ09B0292-0200
Section 13 Watchdog Timer (WDT)
13.1
Overview
A single-channel watchdog timer (WDT) is provided on-chip for monitoring system operations. If
a system becomes uncontrolled and the timer counter overflows without being rewritten correctly
by the CPU, an overflow signal (
WDTOVF
) is output externally. The WDT can simultaneously
generate an internal reset signal for the entire chip.
When this watchdog function is not needed, the WDT can be used as an interval timer. In the
interval timer operation, an interval timer interrupt is generated at each counter overflow. The
WDT is also used when recovering from standby mode, in modifying a clock frequency, and in
clock pause mode.
13.1.1
Features
The WDT includes the following features.
•
Can be switched between watchdog timer mode and interval timer mode.
•
WDTOVF
output in watchdog timer mode
The
WDTOVF
signal is output externally when the counter overflows, and a simultaneous
internal reset of the chip can also be selected (either a power-on reset or manual reset can be
specified).
•
Interrupt generation in interval timer mode
An interval timer interrupt is generated when the counter overflows.
•
Used when standby mode is cleared or the clock frequency is changed, and in clock pause
mode.
•
Choice of eight counter input clocks
Summary of Contents for SH7616
Page 10: ...Rev 2 00 Mar 09 2006 page x of xxvi ...
Page 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Page 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Page 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Page 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Page 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Page 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Page 935: ...SH7616 Hardware Manual ...