58
CHAPTER 3 CPU
3.6.4
Clock Mode
The clock speed is switched by selecting one of four frequency-divided source clocks
(gears).
■
Operations in Each Clock Mode
Each clock mode allows transition to a corresponding standby (sleep/stop) mode. For details of standby
mode, see Section "3.7 Standby Mode (Low-Power Consumption Mode) ".
■
Gears (Clock Speed Switching Function)
Writing one of 00
B
to 11
B
into the clock speed selection bits (SYCC: CS1 and CS0) in the system clock
control register selects one of four clock speeds.
The CPU and peripheral circuits operate using the clock speed selected. However, the gear does not affect
the time-base timer.
Power consumption can be reduced by lowering the clock speed.
Table 3.6-2 Operations in Each Clock Mode
Clock speed
Standby
mode
Clock
Operating clock in each block
Cause that cancels
standby mode
(excepting reset)
SYCC register
(SYCC: CS1
and CS0)
CPU
time-base
timer
Peripheral
function
(1, 1)
High
speed
Low
speed
RUN
Generated
F
CH
/4
F
CH
/2
F
CH
/4
Interrupt request
Sleep
Stopped
Stop
Stopped
Stopped
Stopped
External interrupt
(1, 0)
RUN
Generated
F
CH
/8
F
CH
/2
F
CH
/8
Interrupt request
Sleep
Stopped
Stop
Stopped
Stopped
Stopped
External interrupt
(0, 1)
RUN
Generated
F
CH
/16
F
CH
/2
F
CH
/16
Interrupt request
Sleep
Stopped
Stop
Stopped
Stopped
Stopped
External interrupt
(0, 0)
RUN
Generated
F
CH
/64
F
CH
/2
F
CH
/64
Interrupt request
Sleep
Stopped
Stop
Stopped
Stopped
Stopped
External interrupt
Summary of Contents for F2MC-8L F202RA
Page 2: ......
Page 4: ......
Page 32: ...16 CHAPTER 1 OVERVIEW ...
Page 90: ...74 CHAPTER 3 CPU ...
Page 142: ...126 CHAPTER 5 TIME BASE TIMER POPW A RETI ENDS END ...
Page 150: ...134 CHAPTER 6 WATCHDOG TIMER ...
Page 176: ...160 CHAPTER 7 8 BIT PWM TIMER ...
Page 220: ...204 CHAPTER 8 8 16 BIT CAPTURE TIMER COUNTER ...
Page 240: ...224 CHAPTER 9 12 BIT PPG TIMER ...
Page 274: ...258 CHAPTER 11 EXTERNAL INTERRUPT CIRCUIT 2 LEVEL ...
Page 362: ...346 CHAPTER 15 BUZZER OUTPUT ...
Page 390: ...374 CHAPTER 17 FLASH MEMORY ...
Page 419: ...403 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 434: ...418 INDEX ...
Page 436: ......