Power Management
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
9-12
Freescale Semiconductor
9.4.1.2
Wait Mode
Wait mode is intended to be used to stop only the CPU and memory clocks until a wakeup event is
detected. In this mode, peripherals may be programmed to continue operating and can generate interrupts,
which cause the CPU to exit from wait mode.
9.4.1.3
Doze Mode
Doze mode affects the CPU in the same manner as wait mode, except that each peripheral defines
individual operational characteristics in doze mode. Peripherals which continue to run and have the
capability of producing interrupts may cause the CPU to exit the doze mode and return to run mode.
Peripherals which are stopped restart operation on exit from doze mode as defined for each peripheral.
9.4.1.4
Stop Mode
Stop mode affects the CPU in the same manner as the wait and doze modes, except that all clocks to the
system are stopped and the peripherals cease operation.
Stop mode must be entered in a controlled manner to ensure that any current operation is properly
terminated. When exiting stop mode, most peripherals retain their pre-stop status and resume operation.
The following subsections specify the operation of each module while in and when exiting low-power
modes.
9.4.1.5
Peripheral Shut Down
Most peripherals may be disabled by software to cease internal clock generation and remain in a static
state. Each peripheral has its own specific disabling sequence (refer to each peripheral description for
further details). A peripheral may be disabled at any time and remain disabled during any low-power mode
of operation.
9.4.2
Peripheral Behavior in Low-Power Modes
9.4.2.1
ColdFire Core
The ColdFire core is disabled during any low-power mode. No recovery time is required when exiting any
low-power mode.
9.4.2.2
Static Random-Access Memory (SRAM)
SRAM is disabled during any low-power mode. No recovery time is required when exiting any low-power
mode.
9.4.2.3
Flash
The flash module is in a low-power state if not being accessed. No recovery time is required after exit from
any low-power mode.
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60