Chapter 7 Mode Entry Module (MC_ME)
MPC5602P Microcontroller Reference Manual, Rev. 4
Freescale Semiconductor
167
7.4.3.7
Flash Modules Switch-On
On completion of the step, if one or more of the flashes needs to be switched to normal mode from its
low-power or power-down mode based on the CFLAON and DFLAON bit fields of the
ME_<current mode>_MC and ME_<target mode>_MC registers, the MC_ME requests the flash to exit
from its low-power/power-down mode. When the flashes are available for access, the S_CFLA and
S_DFLA bit fields of the ME_GS register are updated to “11” by hardware.
WARNING
It is illegal to switch the flashes from low-power mode to power-down mode
and from power-down mode to low-power mode. The MC_ME, however,
does not prevent this nor does it flag it.
7.4.3.8
Pad Outputs-On
On completion of the step, if the PDO bit of the ME_<target mode>_MC register is cleared, then
•
all pad outputs are enabled to return to their previous state
•
the I/O pads power sequence driver is switched on
7.4.3.9
Peripheral Clocks Enable
Based on the current and target device modes, the peripheral configuration registers ME_RUN_PC0…7,
ME_LP_PC0…7, and the peripheral control registers ME_PCTL0…143, the MC_ME enables the clocks
for selected modules as required. This step is executed only after the process is completed.
7.4.3.10
Processor and Memory Clock Enable
If the mode transition is from any of the low-power modes HALT0 or STOP0 to RUN0…3, the clocks to
the processor and system memory are enabled. The process of enabling these clocks is executed only after
the
process is completed.
7.4.3.11
Processor Low-Power Mode Exit
If the mode transition is from any of the low-power modes HALT0 orSTOP0 to RUN0…3, the MC_ME
requests the processor to exit from its halted or stopped state. This step is executed only after the
process is completed.
7.4.3.12
System Clock Switching
Based on the SYSCLK bit field of the ME_<current mode>_MC and ME_<target mode>_MC registers,
if the target and current system clock configurations differ, the following method is implemented for clock
switching.
•
The target clock configuration for the 16 MHz int. RC osc. takes effect only after the S_16
MHz_IRC bit of the ME_GS register is set by hardware (i.e., the 16 MHz internal RC oscillator
has stabilized).