MPC555
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MPC556
QUEUED ANALOG-TO-DIGITAL CONVERTER MODULE-64
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
13-16
Figure 13-7 QADC64 Queue Operation with Pause
The queue operating mode selected for queue 1 determines what type of trigger event
causes the execution of each of the sub-queues within queue 1. Similarly, the queue
operating mode for queue 2 determines the type of trigger event required to execute
each of the sub-queues within queue 2.
The choice of single-scan or continuous-scan applies to the full queue, and is not ap-
plied to each sub-queue. Once a sub-queue is initiated, each CCW is executed se-
quentially until the last CCW in the sub-queue is executed and the pause state is
entered. Execution can only continue with the next CCW, which is the beginning of the
next sub-queue. A sub-queue cannot be executed a second time before the overall
queue execution has been completed.
Trigger events which occur during the execution of a sub-queue are ignored, except
that the trigger overrun flag is set. When continuous-scan mode is selected, a trigger
event occurring after the completion of the last sub-queue (after the queue completion
flag is set), causes execution to continue with the first sub-queue, starting with the first
CCW in the queue.
QADC64 CQP
00
BEGIN QUEUE 1
BQ2
63
END OF QUEUE 1
BEGIN QUEUE 2
END OF QUEUE 2
00
63
CHANNEL SELECT,
SAMPLE, HOLD,
A/D
CONVERSION COMMAND WORD
(CCW) TABLE
RESULT WORD TABLE
0
P
0
0
1
0
0
0
1
0
0
0
0
1
0
1
0
1
0
P
1
P
0
PAUSE
PAUSE
PAUSE
PAUSE
PAUSE
PAUSE
AND
CONVERSION
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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