MMC2114 MOTOROLA [Motorola, Inc], MMC2114 Datasheet - Page 508

• Manufacturer Part Number: MMC2114
• Description: M CORE Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Queued Analog-to-Digital Converter (QADC)
Advance Information
508
When any of the end-of-queue conditions is recognized, a queue
completion flag is set, and if enabled, an interrupt is requested. These
situations prematurely terminate queue execution:
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Freescale Semiconductor, Inc.
For More Information On This Product,
Queued Analog-to-Digital Converter (QADC)
Queue 1 is higher in priority than queue 2. When a trigger event
occurs on queue 1 during queue 2 execution, the execution of
queue 2 is suspended by aborting the execution of the CCW in
progress, and queue 1 execution begins. When queue 1 execution
is complete, queue 2 conversions restart with the first CCW entry
in queue 2 or the first CCW of the queue 2 subqueue being
executed when queue 2 was suspended. Alternately, conversions
can restart with the aborted queue 2 CCW entry. The RESUME bit
in QACR2 selects where queue 2 begins after suspension. By
choosing to re-execute all of the suspended queue 2 CCWs
(RESUME = 0), all of the samples are guaranteed to have been
taken during the same scan pass. However, a high trigger event
rate for queue 1 can prevent completion of queue 2. If this occurs,
execution of queue 2 can begin with the aborted CCW entry
(RESUME = 1).
Any conversion in progress for a queue is aborted when that
queue’s operating mode is changed to disabled. Putting a queue
into the disabled mode does not power down the converter.
Changing a queue’s operating mode to another valid mode aborts
any conversion in progress. The queue restarts at its beginning
once an appropriate trigger event occurs.
For low-power operation, the stop bit can be set to prepare the
module for a loss of clocks. The QADC aborts any conversion in
progress when stop mode is entered.
When the QADC debug bit is set and the CPU enters background
debug mode, the QADC freezes at the end of the conversion in
progress. After leaving debug mode, the QADC resumes queue
execution beginning with the next CCW entry. Refer to
Debug Mode
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for more information.
MMC2114 • MMC2113 • MMC2112 — Rev. 1.0
MOTOROLA
19.5.1