MPC5604B/C Microcontroller Reference Manual, Rev. 8
220 Freescale Semiconductor
Figure 10-7 shows an example for a mode transition from RUN0 to STANDBY to DRUN. All power
domains which have PCU_PCONFn.STBY0 cleared will enter power-down phase. In this example only
power domain #1 will be disabled during STANDBY mode.
When the MC_PCU receives the mode change request to STANDBY mode it starts the power down phase
for power domain #1. During the power down phase, clocks are disabled and reset is asserted resulting in
a loss of all information for this power domain. Then the power domain is disconnected from the power
supply (power-down state).
When the MC_PCU receives a system wakeup request, it starts the power-up phase. The power domain is
re-connected to the power supply and the voltage in power domain #1 will increase slowly. Once the
voltage is in an operable range, clocks are enabled and the reset is be deasserted (power-up state).
NOTE
It is possible that due to a wakeup request, power-up is requested before a
power domain completed its power-down sequence. In this case, the
information in that power domain is lost.
10.4.4.3 Power Saving for Memories During STANDBY Mode
All memories which are not powered down during STANDBY mode automatically enter a power saving
state. No software configuration is required to enable this power saving state. While a memory is residing
in this state an increased power saving is achieved. Data in the memories is retained.
new mode
power-down
RUN0
voltage in
PSTAT.PD1
STANDBY
Notes:
Not drawn to scale; PCONF1.RUN0 = 1; PCONF1.STBY0 = 0
current mode
power-up phase
power domain #1
RUN0 STANDBY
DRUN
requested by ME
power-down state
power-up state
power-up state
phase
Mode set due to reset being asserted to power domain #1
wakeup request
Figure 10-7. MC_PCU Events During Power Sequences (STANDBY mode)
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