84
CHAPTER 7 RESET
7.1
Reset Operation
When a reset factor occurs, the CPU stops the current execution immediately and
enters the reset release wait state. When the device is released from the reset, the CPU
reads mode data and the reset vector from internal ROM (mode fetch). When the power
is turned on or when the device is released from a reset in subclock mode or stop
mode, the CPU performs mode fetch after the oscillation stabilization wait time has
passed.
■
Reset Factors
Resets are classified into five reset factors.
●
External reset
An external reset is generated upon "L" level input to the external reset pin (RST).
An externally input reset signal is accepted asynchronously via the internal noise filter and generates an
internal reset signal in synchronization with the machine clock to initialize the internal circuit.
Consequently, a clock is necessary for internal circuit initialization. Clock input is therefore necessary for
operation with an external clock.
Note, however, that external pins (including I/O ports and peripheral resources) are reset asynchronously.
Additionally, there are standard pulse-width values for external reset input. If the value is below the
standard, the reset may not be accepted. The standard value is listed on the data sheet. Please design your
external reset circuit so that this standard is met.
●
Software reset
Writing "1" to the software reset bit of the standby control register (STBC:SRST) generates a software
reset.
●
Watchdog reset
After the watchdog timer starts, a watchdog reset is generated if the watchdog timer is not cleared within a
preset amount of time.
Table 7.1-1 Reset Factors
Reset Factor
Reset Condition
External reset
"L" level input to the external reset pin
Software reset
"1" is written to the software reset bit (STBC: SRST) in the standby control
register.
Watchdog reset
The watchdog timer causes an overflow.
Power-on reset/
low-voltage detection reset
The power is turned on or the supply voltage falls below the detected voltage.
Clock supervisory reset
Oscillation stops abnormally, not caused by a predefined state transition.
Содержание F2 MC-8FX Family
Страница 2: ......
Страница 4: ......
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 ...
Страница 602: ......