Section 15 Watchdog Timer (WDT)
Rev. 3.00 Jan 25, 2006 page 373 of 872
REJ09B0286-0300
Section 15 Watchdog Timer (WDT)
This LSI incorporates two watchdog timer channels (WDT_0 and WDT_1). The watchdog timer
can output an overflow signal (
RESO
) externally if a system crash prevents the CPU from writing
to the timer counter, thus allowing it to overflow. Simultaneously, it can generate an internal reset
signal or an internal NMI interrupt signal.
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. A block
diagram of the WDT is shown in figure 15.1.
15.1
Features
•
Selectable from eight (WDT_0) or 16 (WDT_1) counter input clocks.
•
Switchable between watchdog timer mode and interval timer mode
Watchdog Timer Mode:
•
If the counter overflows, an internal reset or an internal NMI interrupt is generated.
•
When the LSI is selected to be internally reset at counter overflow, a low level signal is output
from the
RESO
pin if the counter overflows.
Internal Timer Mode:
•
If the counter overflows, an internal timer interrupt (WOVI) is generated.
WDT0102A_000020020300
Содержание H8S/2158
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Страница 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Страница 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Страница 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Страница 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Страница 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Страница 744: ...Section 20 Encryption Operation Circuit DES and GF Rev 3 00 Jan 25 2006 page 690 of 872 REJ09B0286 0300...
Страница 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Страница 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Страница 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Страница 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Страница 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Страница 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Страница 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...