QADC
REFERENCE MANUAL
DIGITAL CONTROL
MOTOROLA
7-21
CF1 — Queue 1 Completion Flag
CF1 indicates that a queue 1 scan has been completed. The scan completion flag is
set by the QADC when the input channel sample requested by the last CCW in queue
1 is converted, and the result is stored in the result table.
The end of queue 1 is identified when execution is complete on the CCW in the loca-
tion prior to that pointed to by BQ2, when the current CCW contains an end-of-queue
code instead of a valid channel number, or when the currently completed CCW is in
the last location of the CCW RAM.
When CF1 is set and interrupts are enabled for that queue completion flag, the QADC
asserts an interrupt request at the level specified by IRL1 in the interrupt register
(QADCINT). The software reads the completion flag during an interrupt service routine
to identify the interrupt request. The interrupt request is cleared when the software
writes a zero to the completion flag bit, when the bit was previously read as a one.
Once set, only software or reset can clear CF1.
CF1 is maintained by the QADC regardless of whether the corresponding interrupt is
enabled. The software polls for CF1 bit to see if it is set. This allows the software to
recognize that the QADC is finished with a queue 1 scan. The software acknowledges
that it has detected the completion flag being set by writing a zero to the completion
flag after the bit was read as a one.
Refer to
SECTION 8 INTERRUPTS
for more information.
0 = Queue 1 scan is not complete.
1 = Queue 1 scan is complete.
PF1 — Queue 1 Pause Flag
PF1 indicates that a queue 1 scan has reached a pause. PF1 is set by the QADC when
the current queue 1 CCW has the pause bit set, the selected input channel has been
converted, and the result has been stored in the result table.
Once PF1 is set, the queue enters the paused state and waits for a trigger event to
allow queue execution to continue. However, if the CCW with the pause bit set is the
last CCW in a queue, the queue execution is complete. The queue status becomes
idle, not paused, and both the pause and completion flags are set.
When PF1 is set and interrupts are enabled for the corresponding queue, the QADC
asserts an interrupt request at the level specified by IRL1 in the interrupt register. The
software may read PF1 during an interrupt service routine to identify the interrupt re-
quest. The interrupt request is cleared when the software writes a zero to PF1, when
the bit was previously read as a one. Once set, only software or reset can clear PF1.
PF1 is maintained by the QADC regardless of whether the corresponding interrupts
are enabled. The software may poll PF1 to find out when the QADC has reached a
pause in scanning a queue. The software acknowledges that it has detected a pause
flag being set by writing a zero to PF1 after the bit was last read as a one.
0 = Queue 1 has not reached a pause.
1 = Queue 1 has reached a pause.
F
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