74
CHAPTER 6 CLOCK CONTROLLER
6.8.4
Timebase Timer Mode
Timebase timer mode allows only the main clock oscillation, subclock oscillation,
timebase timer, and watch prescaler to work. The operating clock for the CPU and
peripheral resources is stopped in this mode.
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Operations in Timebase Timer Mode
In timebase timer mode, main clock supply is stopped except for the timebase timer. The device stops all
the functions except timebase timer, external interrupt and low-voltage detection reset while retaining the
contents of registers and RAM that exist immediately before the transition to timebase timer mode.
You can however 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 timebase timer mode
Writing "1" to the watch bit in the standby control register (STBC:TMD) causes the device to enter
timebase timer mode if the system clock monitor bits in the system clock control register (SYCC: SCM1,
0) are "10" or "11".
The device can enter timebase timer mode only when the clock mode is main clock mode or main PLL
clock mode.
Upon transition to timebase timer mode, 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).
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Cancellation of timebase timer mode
The device is released from timebase timer mode in response to a reset, timebase timer interrupt, or
external interrupt.
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
timebase timer mode using an interrupt by the watch prescaler or watch counter.
Note:
When timebase timer mode is canceled via an interrupt, peripheral resources placed into timebase timer 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 timebase timer 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: ......