mcf5282 Freescale Semiconductor, Inc, mcf5282 Datasheet - Page 575

• Manufacturer Part Number: mcf5282
• Manufacturer: Freescale Semiconductor, Inc

The following paragraphs and figures outline the prioritizing criteria used to determine which conversion
occurs in each overlap situation.
Trigger events are described in
When a trigger event causes a CCW execution in progress to be aborted, the aborted conversion is shown
as a ragged end of a shortened CCW rectangle.
The situation diagrams also show when key status bits are set.
Table 28-23
Below the queue execution flows are three sets of blocks that show the status information that is made
available to the user. The first two rows of status blocks show the condition of each queue as:
The third row of status blocks shows the 4-bit QS status register field that encodes the condition of the two
queues. Two transition status cases, QS = 0011 and QS = 0111, are not shown because they exist only very
briefly between stable status conditions.
Freescale Semiconductor
•
•
•
•
•
Idle
Active
Pause
Suspended (queue 2 only)
Trigger pending
describes the status bits.
Trigger
Each situation in
S19. In each diagram, time is shown increasing from left to right. The
execution of queue 1 and queue 2 (Q1 and Q2) is shown as a string of
rectangles representing the execution time of each CCW in the queue. In
most of the situations, there are four CCWs (labeled C1 to C4) in both queue
1 and queue 2. In some of the situations, CCW C2 is presumed to have the
pause bit set, to show the similarities of pause and end-of-queue as
terminations of queue execution.
Trigger overrun
T1
T2
error (TOR)
CF flag
PF flag
Bit
Events that trigger queue 1 execution (external trigger, software-initiated single-scan
enable bit, or completion of the previous continuous loop)
Events that trigger queue 2 execution (external trigger, software-initiated single-scan
enable bit, timer period/interval expired, or completion of the previous continuous
loop)
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3
Table
Set when the end of the queue is reached
Set when a queue completes execution up through a pause bit
Set when a new trigger event occurs before the queue is finished
servicing the previous trigger event
Figure 28-23
28-22.
Table 28-22. Trigger Events
Table 28-23. Status Bits
through
NOTE
Events
Figure 28-33
Function
is labeled S1 through
Queued Analog-to-Digital Converter (QADC)
28-37