MMC2107 Datasheet, PDF (455/618 Pages) –

Freescale Semiconductor, Inc.
Queued Analog-to-Digital Converter (QADC)
Digital Control
QS = 0011 and QS = 0111, are not shown because they exist only very
briefly between stable status conditions.
The first three examples in Figure 18-23 through Figure 18-25 (S1, S2,
and S3) show what happens when a new trigger event is recognized
before the queue has completed servicing the previous trigger event on
the same queue.
In situation S1 (Figure 18-23), one trigger event is being recognized on
each queue while that queue is still working on the previously recognized
trigger event. The trigger overrun error status bit is set, and otherwise,
the premature trigger event is ignored. A trigger event which occurs
before the servicing of the previous trigger event is through does not
disturb the queue execution in progress.
T1
T1
Q1: C1 C2 C3 C4
TOR1
CF1
T2
T2
Q2: C1 C2 C3 C4
Q1
IDLE
ACTIVE
TOR2
CF2
IDLE
Q2
IDLE
ACTIVE
IDLE
QS
0000
1000
0000
0010
0000
Figure 18-23. CCW Priority Situation 1
MMC2107 – Rev. 2.0
MOTOROLA
Queued Analog-to-Digital Converter (QADC)
For More Information On This Product,
Go to: www.freescale.com
Technical Data
455