178
CHAPTER 11 WATCHDOG TIMER
11.4
Explanation of Watchdog Timer Operations and Setup
Procedure Example
The watchdog timer generates a watchdog reset when the watchdog timer counter
overflows.
■
Operations of Watchdog Timer
●
How to activate the watchdog timer
•
The timer of the watchdog timer is activated when "0101
B
" is written to the watchdog control bits of the
watchdog timer control register (WDTC:WTE3 to WTE0) for the first time after a reset. The count
clock switch bits of the watchdog timer control register (WDTC:CS1,0) should also be set at the same
time.
•
Once the watchdog timer is activated, a reset is the only way to stop its operation.
●
Clearing the watchdog timer
•
When the counter of the watchdog timer is not cleared within the interval time, it overflows, allowing
the watchdog timer to generate a watchdog reset.
•
The counter of the watchdog timer is cleared when "0101
B
" is written to the watchdog control bits of the
watchdog timer control register (WDTC:WTE3 to WTE0) for the second or any succeeding time.
•
The watchdog timer is cleared at the same time as the timer selected as the count clock (timebase timer
or watch prescaler) is cleared.
●
Operation in standby mode
Regardless of the clock mode selected, the watchdog timer clears its counter and stops the operation when
entering a standby mode (sleep/stop/timebase timer/watch).
Once released from the standby mode, the timer restarts the operation.
Note:
The watchdog timer is also cleared when the timer selected as the count clock (timebase timer or
watch prescaler) is cleared.
For this reason, the watchdog timer cannot function as such, if the software is set to clear the
selected timer repeatedly during the interval time of the watchdog timer.
Содержание F2 MC-8FX Family
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Страница 30: ...16 CHAPTER 1 DESCRIPTION 1 FPT 64P M23 FPT 64P M24 2 For the I O circuit type refer to 1 8 I O Circuit Type ...
Страница 34: ...20 CHAPTER 1 DESCRIPTION ...
Страница 35: ...21 CHAPTER 2 HANDLING DEVICES This chapter gives notes on using 2 1 Device Handling Precautions ...
Страница 38: ...24 CHAPTER 2 HANDLING DEVICES ...
Страница 39: ...25 CHAPTER 3 MEMORY SPACE This chapter describes memory space 3 1 Memory Space 3 2 Memory Map ...
Страница 43: ...29 CHAPTER 4 MEMORY ACCESS MODE This chapter describes the memory access mode 4 1 Memory Access Mode ...
Страница 56: ...42 CHAPTER 5 CPU ...
Страница 73: ...59 CHAPTER 6 CLOCK CONTROLLER ...
Страница 96: ...82 CHAPTER 6 CLOCK CONTROLLER ...
Страница 104: ...90 CHAPTER 7 RESET ...
Страница 105: ...91 CHAPTER 8 INTERRUPTS This chapter explains the interrupts 8 1 Interrupts ...
Страница 174: ...160 CHAPTER 10 TIMEBASE TIMER ...
Страница 184: ...170 CHAPTER 10 TIMEBASE TIMER ...
Страница 218: ...204 CHAPTER 13 WATCH PRESCALER ...
Страница 257: ...243 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Страница 261: ...247 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Страница 288: ...274 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Страница 301: ...287 CHAPTER 17 16 BIT PPG TIMER ...
Страница 316: ...302 CHAPTER 17 16 BIT PPG TIMER ...
Страница 382: ...368 CHAPTER 21 UART SIO DEDICATED BAUD RATE GENERATOR ...
Страница 390: ...376 CHAPTER 22 I2C ...
Страница 395: ...381 CHAPTER 22 I2C ...
Страница 399: ...385 CHAPTER 22 I2C ...
Страница 430: ...416 CHAPTER 23 10 BIT A D CONVERTER ...
Страница 476: ...462 CHAPTER 24 LCD CONTROLLER ...
Страница 482: ...468 CHAPTER 25 LOW VOLTAGE DETECTION RESET CIRCUIT ...
Страница 494: ...480 CHAPTER 26 CLOCK SUPERVISOR ...
Страница 507: ...493 CHAPTER 27 REAL TIME CLOCK ...
Страница 523: ...509 CHAPTER 27 REAL TIME CLOCK ...
Страница 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Страница 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
Страница 554: ...540 CHAPTER 28 256 KBIT FLASH MEMORY ...
Страница 564: ...550 CHAPTER 29 EXAMPLE OF SERIAL PROGRAMMING CONNECTION ...
Страница 595: ...581 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Страница 596: ...582 INDEX Index ...
Страница 597: ...583 INDEX ...
Страница 599: ...585 Pin Function Index V2 LCD power supply driving pin 2 439 V3 LCD power supply driving pin 3 439 ...
Страница 600: ...586 Pin Function Index ...
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