
67
3.7 Clock
3.7.4
Clock Modes
The main clock mode and subclock mode are available as the clock mode.
In main clock mode, the main clock is the main operating clock. The speed of the main
clock can be switched by selecting from four kinds of clocks created by dividing its
oscillation (gear function).
In subclock mode, the oscillation of the man clock is stopped and the subclock alone
becomes the operating clock.
I
Operating State of the Clock Mode
In each clock mode, a transition can be made to the standby mode corresponding to each
mode. For the standby mode, see Section 3.8 "Standby Mode (low power consumption)".
Table 3.7-2 Operating State of the Clock Mode
Clock
mode
Main clock speed
SYCC register
(CS1, CS0)
Standby
mode
Clock generation
Operation clock in each section
Release source
of standby mode
(other than
resets)
Main
Sub
CPU
timebas
e timer
Each
peripheral
watch
prescaler
Main
clock
mode
(1.1)
RUN
Oscillation
Oscillation
F
CH
/4
F
CH
/2
F
CH
/4
F
CL
Various interrupt
requests
Sleep
Stop
Stop
Stop
Stop
Stop
External interrupt
(1.0)
RUN
Oscillation
Oscillation
F
CH
/8
F
CH
/2
F
CH
/8
F
CL
Various interrupt
requests
Sleep
Stop
Stop
Stop
Stop
Stop
External interrupt
(0.1)
RUN
Oscillation
Oscillation
F
CH
/16
F
CH
/2
F
CH
/16
F
CL
Various interrupt
requests
Sleep
Stop
Stop
Stop
Stop
Stop
External interrupt
(0.0)
RUN
Oscillation
Oscillation
F
CH
/64
F
CH
/2
F
CH
/64
F
CL
Various interrupt
requests
Sleep
Stop
Stop
Stop
Stop
Stop
External interrupt
Subclock
mode
-
RUN
Stop
Oscillation
F
CL
Stop
(*1)
F
CL
F
CL
Various interrupt
requests
Sleep
Stop
Stop
Stop
Stop
Stop
External interrupt
Watch
mode
Stop
Oscillation
Stop
Stop
(*1)
Stop
F
CL
External interrupt,
watch interrupt
F
CH
: Main clock oscillation
F
CL
: Subclock oscillation
*1: Since the timebase timer is operated by the main clock, it stops operation in subclock mode.
High
speed
Low
speed