Qadc Control Register 2 (Qacr2) - Motorola ColdFire MCF5281 User Manual

If BQ2[6:0] is changed while queue 1 is active, the effect of BQ2[6:0] as an end-of-queue
indication for queue 1 is immediate. However, beware of the risk of losing the end-of-queue
1 when changing BQ2[6:0]. Using EOQ (channel 63) to end queue 1 is recommended.
If BQ2[6:0] was assigned to the CCW that queue 1 is currently
working on, then that conversion is completed before the
change to BQ2[6:0] takes effect.
Each time a CCW is read for queue 1, the CCW location is compared with the current value
of the BQ2[6:0] pointer to detect a possible end-of-queue condition. For example, if
BQ2[6:0] is changed to CCW3 while queue 1 is converting CCW2, queue 1 is terminated
after the conversion is completed. However, if BQ2[6:0] is changed to CCW1 while queue
1 is converting CCW2, the QADC would not recognize a BQ2[6:0] end-of-queue condition
until queue 1 execution reached CCW1 again, presumably on the next pass through the
queue.
Stop mode resets this register (0x007f)
15
Field CIE2
Reset
R/W:
7
Field RESUME
Reset
R/W:
Address
MOTOROLA
14 13
PIE2 SSE2
6 5
BQ26 BQ25
IPSBAR + 0x19_000e, 0x19_000f
Figure 27-10. QADC Control Register 2 (QACR2)
Chapter 27. Queued Analog-to-Digital Converter (QADC)
NOTE
12 11
MQ212 MQ211 MQ210
0000_0000
R/W
4 3
BQ24 BQ23
0111_1111
R/W
Register Descriptions
10 9
MQ29 MQ28
2 1
BQ22 BQ21 BQ20
8
0
27-17