180
CHAPTER 11 WATCHDOG TIMER
11.5
Precautions when Using Watchdog Timer
Care must be taken for the following points when using the watchdog timer.
■
Precautions when Using Watchdog Timer
●
Stopping the watchdog timer
Once activated, the watchdog timer cannot be stopped until a reset is generated.
●
Selecting the count clock
The count clock switch bits (WDTC:CS1,0) can be rewritten only when the watchdog control bits
(WDTC:WTE3 to WTE0) are set to "0101
B
" upon the activation of the watchdog timer. The count clock
switch bits cannot be written by a bit operation instruction. Moreover, the bit settings should not be
changed once the timer is activated.
In the subclock mode, the timebase timer does not operate because the main clock stops oscillating.
In order to operate the watchdog timer in the subclock mode, it is necessary to select the watch prescaler as
the count clock beforehand and set "WDTC:CS1,0" to "10
B
" or "11
B
".
●
Clearing the watchdog timer
Clearing the counter used for the count clock of the watchdog timer (timebase timer or watch prescaler)
also clears the counter of the watchdog timer.
The counter of the watchdog timer is cleared when entering the sleep mode, stop mode or watch mode.
●
Programming precaution
When creating a program in which the watchdog timer is cleared repeatedly in the main loop, set the
processing time of the main loop including the interrupt processing time to the minimum watchdog timer
interval time or shorter.
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 ...
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Страница 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Страница 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
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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 ...
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Страница 599: ...585 Pin Function Index V2 LCD power supply driving pin 2 439 V3 LCD power supply driving pin 3 439 ...
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