XC878CLM Datasheet, PDF (86/139 Pages) Infineon Technologies AG – 8-Bit Single-Chip Microcontroller

XC878CLM
Advance Information
Functional Description
3.9
Power Saving Modes
The power saving modes of the XC878 provide flexible power consumption through a
combination of techniques, including:
• Stopping the CPU clock
• Stopping the clocks of individual system components
• Reducing clock speed of some peripheral components
• Power-down of the entire system with fast restart capability
After a reset, the active mode (normal operating mode) is selected by default (see
Figure 22) and the system runs in the main system clock frequency. From active mode,
different power saving modes can be selected by software. They are:
• Idle mode
• Slow-down mode
• Power-down mode
any interrupt
& SD=0
set IDLE
bit
IDLE
ACTIVE
set SD
bit
clear SD
bit
EXINT0/RXD pin
& SD=0
set PD
bit
POWER-DOWN
set IDLE
bit
any interrupt
& SD=1
SLOW-DOWN
set PD
bit
EXINT0/RXD pin
& SD=1
Figure 22 Transition between Power Saving Modes
Data Sheet
79
V0.1, 2008-04