MPC555
/
MPC556
CLOCKS AND POWER CONTROL
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
8-19
Figure 8-9 MPC555
/
MPC556 Low-Power Modes Flow Diagram
Normal
High Mode
LPM = 00
CSRC = 0/1
Normal-Low
LPM = 00, CSRC = 1
Doze-Low
LPM = 01, CSRC = 1
Doze-High
LPM = 01, CSRC = 0/1
Sleep Mode
LPM = 10, CSRC = 0
Deep-Sleep Mode
LPM = 11, CSRC = 0,
Power-Down Mode
LPM = 11, CSRC = 0,
(MSR
POW
+IntCSRC
(
(MSR
POW
+Interrupt)
)
*CSRC***
Interrupt
Software *
Software *
Software *
Software *
Software *
Async. Wake-up or
Interrupt
Wake-up:
Frequency Clocks
Wake-up: 3 - 4 SysFreq
Clocks
500 Input
Software is active only in normal-high/low modes
Software *
RTC/PIT/TB/DEC Interrupt followed
Hard Reset
Asynchronous
Wake-up: 3 - 4 SysFreqmax
Interrupts
Clocks
TEXPS = 1
TEXPS = 0**
TEXPS receives the zero value by writing one. Writing of zero has no effect on TEXPS.
by External Hard Reset
Software *
The switch from normal-high to normal-low is enable only if the conditions to asynchronous
interrupt are cleared
or External Hard Reset
***
**
*
RTC/PIT/TB/DEC
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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