73
CHAPTER 6 CLOCK CONTROLLER
6.8.3
Stop Mode
Stop mode stops the main clock.
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Operations in Stop Mode
Stop mode stops the main clock. In this mode, the device stops all the functions except external interrupt
and low-voltage detection reset while retaining the contents of registers and RAM that exist immediately
before the transition to stop mode.
In main clock mode or main PLL clock mode, however, you can start or stop subclock oscillation by setting
the subclock oscillation stop bit in the system clock control register (SYCC: SUBS). When the subclock is
oscillating, the watch prescaler and watch counter operate.
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Transition to stop mode
Writing "1" to the stop bit in the standby control register (STBC:STP) causes the device to enter stop mode.
At this time, the states of external pins are retained when the pin state setting bit in the standby control
register (STBC:SPL) is "0", and the states of external pins become high impedance when that bit is "1"
(those pins are pulled up for which pull-up resistor connection has been selected in the pull-up setting
register).
In main clock mode or main PLL clock mode, a timebase timer interrupt request may be generated while
the device is waiting for main clock oscillation to stabilize after being released from stop mode by an
interrupt. If the interrupt interval time of the timebase timer is shorter than the main clock oscillation
stabilization wait time, you should disable interrupt requests output from the timebase timer before entering
stop mode, thereby preventing unexpected interrupts from occurring.
You should also disable interrupt requests output from the watch prescaler before entering stop mode in
subclock mode.
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Cancellation of stop mode
The device is released from stop mode in response to a reset or an external interrupt.
In main clock mode or main PLL clock mode, you can start or stop subclock oscillation by setting the
subclock oscillation stop bit in the system clock control register (SYCC: SUBS). When the subclock is
oscillating, you can also release the device from stop mode using an interrupt by the watch prescaler or
watch counter.
Note:
When stop mode is canceled via an interrupt, peripheral resources placed into stop mode during an action
resume that action. Therefore, the initial interval time of the interval timer and other similar settings are
rendered indeterminate. After recovery from stop mode, initialize each peripheral resource as necessary.
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: ......