MPC555
/
MPC556
CLOCKS AND POWER CONTROL
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
8-22
Figure 8-10 Basic Power Supply Configuration
8.9.3 Keep Alive Power
8.9.3.1 Keep Alive Power Configuration
illustrates an example of a switching scheme for an optimized low-power
system. SW1 and SW2 can be unified in only one switch if VDDSYN and VDDI/VDDL
are supplied by the same source.
Clock Control
PLL
PIT, RTC, TB,
and DEC
Internal Logic
VDDL
I / O
VDDI
VDDSYN
KAPWR
TEXP
Oscillator,
VDDSRAM
VDDI
VDDH
VPP
VDDF
FLASH
SRAM
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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