Chapter 2 CPU Basics

2-4 Standby Function

2-4-1 Overview

This LSI has two sets of system clock oscillator (high speed oscillation, low speed oscillation) for two CPU operating modes (NORMAL and SLOW), each with two standby modes (HALT and STOP). Power consumption can be decreased with using those modes.

Reset

CPU operation mode

STANDBY mode

 

Interrupt

STOP0

NORMAL mode

 

 

OSC: Halt

 

Program 5

XI : Halt

NORMAL

 

 

 

OSC: Oscillation

 

 

XI: Oscillation

Interrupt

 

 

HALT 0

 

 

 

 

OSC: Oscillation

 

Program 4

Xl: Oscillation

Program 3

 

 

STOP mode

IDLE

 

 

 

OSC: Oscillation

 

 

XI: Oscillation

 

 

Program1

 

HALT mode

Program 2

 

 

 

 

Interrupt

STOP1

 

 

 

 

OSC: Halt

SLOW

Program 5

XI: Halt

OSC: Halt

 

 

 

XI: Oscillation

 

 

 

Interrupt

HALT 1

SLOW mode

 

 

OSC: Halt

 

 

 

Program 4

XI: Oscillation

 

 

:CPU halt : Wait period for oscillation stabilization is inserted OSC: High-frequency oscillation clock XI: Low-frequency oscillation clock (32 kHz)

Figure 2-4-1 Transition Between Operation Modes

Standby Functions

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Panasonic F77G, MN101C77C user manual Standby Function, Transition Between Operation Modes