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3.8 Standby Mode (Low Power Consumption)
3.8.1
Operating State in Standby Mode
This section describes the operating states of CPU and peripheral functions in
standby mode.
I
Operating State in Standby Mode
H
Pin state in standby mode
Most I/O pins can, independent of the clock mode, retain the state just before transition to the
stop or watch mode or can be put into high impedance using the pin state designate bit (STBC:
SPL) of the standby control register.
Table 3.8-1 The Operating States of CPU and Peripheral Functions in Standby Mode
Operation mode
Main clock mode
Subclock mode
Function
RUN
Sleep
Stop
(SPL=0)
Stop
(SPL=1)
RUN
Sleep
Stop
(SPL=0)
Stop
(SPL=1)
Clock
Main clock
Operating
Operating
Stopped
Stopped
Stopped
Stopped
Stopped
Stopped
Stopped
Subclock
Operating
Operating
Operating
Operating
Operating
Operating
Stopped
Stopped
Operating
CPU
Instruction
Operating
Stopped
Stopped
Stopped
Operating
Stopped
Stopped
Stopped
Stopped
ROM
Operating
Retained
Retained
Retained
Operating
Retained
Retained
Retained
Retained
RAM
Peripheral
functions
I/O port
Operating
Retained
Retained
Retained
Operating
Retained
Retained
Retained
Retained
timebase timer
Operating
Operating
Stopped
Stopped
Stopped
Stopped
Stopped
Stopped
Stopped
Watchdog timer
Operating
Stopped
Stopped
Stopped
Operating
(*4)
Stopped
Stopped
Stopped
Stopped
Multi-address I
2
C bus
Operating
Operating
Stopped
Stopped
Operating
Operating
Stopped
Stopped
Stopped
I
2
C bus
Operating
Operating
Stopped
Stopped
Operating
Operating
Stopped
Stopped
Stopped
UART/SIO
Operating
Operating
Stopped
Stopped
Operating
Operating
Stopped
Stopped
Stopped
Comparator
Operating
Operating
Operating
Operating
Operating
Operating
Operating
Operating
Operating
A/D converter
Operating
Operating
Stopped
Stopped
Operating
Operating
Stopped
Stopped
Stopped
External interrupt
Operating
Operating
Operating
Operating
Operating
Operating
Operating
Operating
Operating
watch prescaler
Operating
Operating
Operating
(*1)
Operating
(*1)
Operating
Operating
Stopped
Stopped
Operating
LCD controller/driver
Operating
Operating
Operating
(*2)
Operating
(*2)
Operating
(*2)
Operating
(*2)
Stopped
Stopped
Operating
(*2)
D/A converter
Operating
Operating
Stopped
Stopped
Operating
Operating
Stopped
Stopped
Stopped
8/16-bit timer
Operating
Operating
Stopped
Stopped
Operating
Operating
Stopped
Stopped
Stopped
16-bit timer
Operating
Operating
Stopped
Stopped
Operating
Operating
Stopped
Stopped
Stopped
Pin
Operating
Retained
Retained
Hi-z
Operating
Retained
Retained
Hi-z
Retained
How to release
Reset/
various
interrupts
Reset/
various
interrupts
Reset/
various
interrupts
Reset/
various
interrupts
Reset/
various
interrupts
Reset/
various
interrupts
Reset/
various
interrupts
Reset/
various
interrupts
Reset/
various
interrupts
*1: The watch prescaler carries out the count operation, but no watch interrupt occurs.
*2: The subclock is selected as the operating clock. Operation permission is required in watch mode.