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MMC2107 Datasheet, PDF (333/618 Pages) –
Freescale Semiconductor, Inc.
Serial Communications Interface Modules (SCI1 and SCI2)
Modes of Operation
16.5 Modes of Operation
SCI operation is identical in run, special, and emulation modes. The SCI
has two low-power modes, doze and stop.
NOTE: Run mode is the normal mode of operation and the WAIT instruction
does not affect SCI operation.
16.5.1 Doze Mode
When the SCIDOZ bit in the SCI pullup and reduced drive (SCIPURD)
register is set, the DOZE instruction stops the SCI clock and puts the SCI
in a low-power state. The DOZE instruction does not affect SCI register
states. Any transmission or reception in progress stops at doze mode
entry and resumes when an internal or external interrupt request brings
the CPU out of doze mode. Exiting doze mode by reset aborts any
transmission or reception in progress and resets the SCI.
When the SCIDOZ bit is clear, execution of the DOZE instruction has no
effect on the SCI. Normal module operation continues, allowing any SCI
interrupt to bring the CPU out of doze mode.
16.5.2 Stop Mode
The STOP instruction stops the SCI clock and puts the SCI in a
low-power state. The STOP instruction does not affect SCI register
states. Any transmission or reception in progress halts at stop mode
entry and resumes when an external interrupt request brings the CPU
out of stop mode. Exiting stop mode by reset aborts any transmission or
reception in progress and resets the SCI.
MMC2107 – Rev. 2.0
MOTOROLA
Serial Communications Interface Modules (SCI1 and SCI2)
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Technical Data
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