Renesas H8SX series, Hardware Manual

Page: 709 / 846

Section 19 Power-Down Modes
Rev. 3.00 Mar. 14, 2006 Page 671 of 804
REJ09B0104-0300
Section 19 Power-Down Modes
This LSI has power consumption reduction functions, such as multi-clock function, module stop
function, and transition function to power-down mode.
19.1 Features
•
Multi-clock function
The frequency division ratio is settable independently for the system clock, peripheral module
clock, and external bus clock.
•
Module stop function
The functions for each peripheral modules can be stopped to make a transition to a power-
down mode.
•
Transition function to power-down mode
Transition to a power-down mode is possible to stop the CPU, all the on-chip peripheral
modules, and oscillator.
•
Three power-down modes
Sleep mode
All-module-clock-stop mode
Software standby mode
Table 19.1 shows conditions for making a transition to a power-down mode, states of the CPU and
peripheral modules, and clearing method for each mode. After the reset state, since this LSI
operates in normal program execution state, the modules, other than the DMAC are stopped.
Table 19.1 Operating States
Operating State Sleep Mode All-Module-Clock-Stop Mode Software Standby Mode
Transition
condition Control re
instruction Control re instruction Control re instruction
Cancellation
method Interrupt Interrupt *
2
External interrupt
Oscillator Functions Functions Halted
CPU Halted (retained) Halted (retained) Halted (retained)
Watchdog timer Functions Functions Halted (retained)
Other peripheral
modules Functions Halted
*
3
Halted
*
1
Downloaded from Elcodis.com electronic components distributor