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CHAPTER 6 CLOCK CONTROLLER
6.8.1
Notes on Using Standby Mode
Even if the standby control register (STBC) sets standby mode, transition to the
standby mode does not take place when an interrupt request has been issued from a
peripheral resource. When the device returns from standby mode to the normal
operating state in response to an interrupt, the operation that follows varies depending
on whether the interrupt request is accepted or not.
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Place at Least Three NOP Instructions Immediately Following a Standby Mode Setting
Instruction.
The device requires four machine clock cycles before entering standby mode after it is set in the standby
control register. During that period, the CPU executes the program. To avoid program execution during this
transition to standby mode, enter at least three NOP instructions.
The device operates normally if you place instructions other than NOP instructions. In that case, however,
note that the device may execute the instructions to be executed after being released from standby mode
before entering the standby mode and that the device may enter the standby mode during instruction
execution, which is resumed after the device is released from the standby mode (increasing the number of
instruction execution cycles).
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Check That Clock-mode Transition has been Completed before Setting Standby Mode.
Before setting standby mode, make sure that clock-mode transition has been completed by comparing the
values of the clock mode monitor bit (SYCC: SCM1, 0) and clock mode setting bit (SYCC: SCS1, 0) in the
system clock control register.
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An Interrupt Request may Suppress Transition to Standby Mode.
If an attempt is made to set a standby mode while an interrupt request with an interrupt level higher than
"11" has been issued, the device ignores the attempt to write to the standby control register and continues
instruction execution without entering the standby mode. The device does not enter the standby mode even
after having serviced the interrupt.
This behavior is the same as when interrupts are disabled by the interrupt enable flag (CCR:I) and interrupt
level bits in the condition code register (CCR:IL 1,0) of the CPU.
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Standby Mode is Also Canceled when the CPU Rejects Interrupts.
When an interrupt request with an interrupt level higher than "11" is issued in standby mode, the device is
released from the standby mode regardless of the settings of the interrupt enable flag (CCR: I) and interrupt
level bits (CCR:IL1,0) of the condition code register of the CPU.
After being released from standby mode, the device services the interrupt when the CPU's condition code
register has been set to accept interrupts. If the register has been set to reject interrupts, the device resumes
processing from the instruction that follows the last instruction executed before entering the standby mode.
Summary of Contents for F2 MC-8FX Family
Page 2: ......
Page 4: ......
Page 34: ...20 CHAPTER 1 DESCRIPTION ...
Page 38: ...24 CHAPTER 2 HANDLING DEVICES ...
Page 39: ...25 CHAPTER 3 MEMORY SPACE This chapter describes memory space 3 1 Memory Space 3 2 Memory Map ...
Page 56: ...42 CHAPTER 5 CPU ...
Page 73: ...59 CHAPTER 6 CLOCK CONTROLLER ...
Page 96: ...82 CHAPTER 6 CLOCK CONTROLLER ...
Page 104: ...90 CHAPTER 7 RESET ...
Page 105: ...91 CHAPTER 8 INTERRUPTS This chapter explains the interrupts 8 1 Interrupts ...
Page 174: ...160 CHAPTER 10 TIMEBASE TIMER ...
Page 184: ...170 CHAPTER 10 TIMEBASE TIMER ...
Page 218: ...204 CHAPTER 13 WATCH PRESCALER ...
Page 257: ...243 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 261: ...247 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 288: ...274 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 301: ...287 CHAPTER 17 16 BIT PPG TIMER ...
Page 316: ...302 CHAPTER 17 16 BIT PPG TIMER ...
Page 382: ...368 CHAPTER 21 UART SIO DEDICATED BAUD RATE GENERATOR ...
Page 390: ...376 CHAPTER 22 I2C ...
Page 395: ...381 CHAPTER 22 I2C ...
Page 399: ...385 CHAPTER 22 I2C ...
Page 430: ...416 CHAPTER 23 10 BIT A D CONVERTER ...
Page 476: ...462 CHAPTER 24 LCD CONTROLLER ...
Page 482: ...468 CHAPTER 25 LOW VOLTAGE DETECTION RESET CIRCUIT ...
Page 494: ...480 CHAPTER 26 CLOCK SUPERVISOR ...
Page 507: ...493 CHAPTER 27 REAL TIME CLOCK ...
Page 523: ...509 CHAPTER 27 REAL TIME CLOCK ...
Page 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Page 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 554: ...540 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 564: ...550 CHAPTER 29 EXAMPLE OF SERIAL PROGRAMMING CONNECTION ...
Page 595: ...581 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 596: ...582 INDEX Index ...
Page 597: ...583 INDEX ...
Page 600: ...586 Pin Function Index ...
Page 602: ......