Rev. 1.0, 09/01, page 618 of 904
14.4
Operation
14.4.1
Watchdog Timer Mode
To use the WDT as a watchdog timer mode, set the WT/
,7
and TME bits in TCSR to 1.
If TCNT overflows without being rewritten because of a system crash or other error, the
:'729)
signal is output.
This ensures that TCNT does not overflow while the system is operating normally. Software must
prevent TCNT overflows by rewriting the TCNT value (normally be writing H'00) before
overflow occurs. This
:'729)
signal can be used to reset the chip internally in watchdog timer
mode.
If TCNT overflows when 1 is set in the RSTE bit in RSTCSR, a signal that resets this LSI
internally is generated at the same time as the
:'729)
signal. If a reset caused by a signal input
to the
5(6
pin occurs at the same time as a reset caused by a WDT overflow, the
5(6
pin reset
has priority and the WOVF bit in RSTCSR is cleared to 0.
The
:'729)
signal is output for 132 states when RSTE = 1, and for 130 states when RSTE = 0.
The internal reset signal is output for 518 states.
When TCNT overflows in watchdog timer mode, the WOVF bit in RSTCSR is set to 1. If TCNT
overflows when 1 is set in the RSTE bit in RSTCSR, an internal reset signal is generated to the
entire chip.
Содержание H8S/2376 F-ZTAT
Страница 24: ...Rev 1 0 09 01 page xxiv of xliv ...
Страница 38: ...Rev 1 0 09 01 page xxxviii of xliv ...
Страница 44: ...Rev 1 0 09 01 page xliv of xliv ...
Страница 60: ...Rev 1 0 09 01 page 16 of 904 ...
Страница 96: ...Rev 1 0 09 01 page 52 of 904 ...
Страница 116: ...Rev 1 0 09 01 page 72 of 904 ...
Страница 148: ...Rev 1 0 09 01 page 104 of 904 ...
Страница 284: ...Rev 1 0 09 01 page 240 of 904 ...
Страница 422: ...Rev 1 0 09 01 page 378 of 904 ...
Страница 634: ...Rev 1 0 09 01 page 590 of 904 ...
Страница 656: ...Rev 1 0 09 01 page 612 of 904 ...
Страница 668: ...Rev 1 0 09 01 page 624 of 904 ...
Страница 780: ...Rev 1 0 09 01 page 736 of 904 ...
Страница 796: ...Rev 1 0 09 01 page 752 of 904 ...
Страница 806: ...Rev 1 0 09 01 page 762 of 903 ...
Страница 808: ...Rev 1 0 09 01 page 764 of 904 ...
Страница 921: ...Rev 1 0 09 01 page 877 of 904 ø tBRQOD tBRQOD Figure 24 24 External Bus Request Output Timing ...
Страница 938: ...Rev 1 0 09 01 page 894 of 904 ...