PXD10RM Datasheet, PDF (1001/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

power domain #2 will increase slowly. Once the voltage of power domain #2 is within an operable range,
its clocks are enabled, and its resets are deasserted (power-up state).
NOTE
It is possible that, due to a mode change, power-up is requested before a
power domain completed its power-down sequence. In this case, the
information in that power domain is lost.
29.4.4.2 STANDBY Mode Transition
STANDBY offers the maximum power saving. The level of power saving is software-controllable via the
settings in the PCU_PCONFn registers for power domain #2 onwards. Power domain #0 stays connected
to the power supply while power domain #1 is disconnected from the power supply. Amongst others power
domain #1 contains the platform and the MC_ME. Therefore this mode differs from all other user/system
modes.
Once STANDBY is entered it can only be left via a system wakeup. On exiting the STANDBY mode, all
power domains are powered up according to the settings in the PCU_PCONFn registers, and the DRUN
mode is entered. In DRUN mode, at least power domains #0 and #1 are powered.
Figure 29-7 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).
Freescale Semiconductor
PXD10 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
29-9