Power Management
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
9-14
Freescale Semiconductor
In stop mode, the QSPI stops immediately and freezes operation, register values, state machines, and
external pins. During this mode, the QSPI clocks are shut down. Coming out of stop mode returns the QSPI
to operation from the state prior to the low-power mode entry.
9.4.2.9
DMA Timers (DTIM0–DTIM3)
In wait and doze modes, the DMA timers may generate an interrupt to exit a low-power mode. This
interrupt can be generated when the DMA Timer is in input capture mode or reference compare mode.
In input capture mode, where the capture enable (CE) field of the timer mode register (DTMR) has a
non-zero value and the DMA enable (DMAEN) bit of the DMA timer extended mode register (DTXMR)
is cleared, an interrupt is issued upon a captured input. In reference compare mode, where the output
reference request interrupt enable (ORRI) bit of DTMR is set and the DTXMR[DMAEN] bit is cleared,
an interrupt is issued when the timer counter reaches the reference value.
DMA timer operation is disabled in stop mode, but the DMA timer is unaffected by the wait or doze modes
and may generate an interrupt to exit these modes. Upon exiting stop mode, the timer resumes operation
unless stop mode was exited by reset.
9.4.2.10
Interrupt Controllers (INTC0, INTC1)
The interrupt controller is not affected by any of the low-power modes. All logic between the input sources
and generating the interrupt to the processor is combinational to allow the ability to wake up the CPU
processor during low-power stop mode when all system clocks are stopped.
An interrupt request causes the CPU to exit a low-power mode only if that interrupt’s priority level is at or
above the level programmed in the interrupt priority mask field of the CPU’s status register (SR). The
interrupt must also be enabled in the interrupt controller’s interrupt mask register as well as at the module
from which the interrupt request would originate.
9.4.2.11
Fast Ethernet Controller (FEC)
In wait and doze modes, the FEC may generate an interrupt to exit the low-power modes.
•
Clearing the ECNTRL[ETHER_EN] bit disables the FEC function.
•
The FEC is unaffected by wait mode and may generate an interrupt to exit this mode.
In stop mode, the FEC stops immediately and freezes operation, register values, state machines, and
external pins. During this mode, the FEC clocks are shut down. Coming out of stop mode returns the FEC
to operation from the state prior to the low-power mode entry.
9.4.2.12
I/O Ports
The I/O ports are unaffected by entry into a low-power mode. These pins may impact low-power current
draw if they are configured as outputs and are sourcing current to an external load. If low-power mode is
exited by a reset, the state of the I/O pins reverts to their default direction settings.
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
