2.12 Event Dataflow
Event Dataflow
www.ti.com
This section summarizes the data flow of a single event, from the time the event is latched to the channel
controller to the time the transfer completion code is returned. The following steps list the sequence of
EDMA3CC activity:
1. Event is asserted from an external source (peripheral or external interrupt). This also is similar for a
manually-triggered, chained-triggered, or QDMA-triggered event. The event is latched into the
ER.E
n
/ERH.E
n
(or CER.E
n
/CERH.E
n
, ESR.E
n
/ESRH.E
n
, QER.E
n
) bit.
2. Once an event is prioritized and queued into the appropriate event queue, the SER.E
n
\SERH.E
n
(or
QSER.E
n
) bit is set to inform the event prioritization/processing logic to disregard this event since it is
already in the queue. Alternatively, if the transfer controller and the event queue are empty, then the
event bypasses the queue.
3. The EDMA3CC processing and the submission logic evaluates the appropriate PaRAM set and
determines whether it is a non-null and non-dummy transfer request (TR).
4. The EDMA3CC clears the ER.E
n
/ERH.E
n
(or CER.E
n
/CERH.E
n
, ESR.E
n
/ESRH.E
n
, QER.E
n
) bit and
the SER.E
n
/SERH.E
n
bit as soon as it determines the TR is non-null. In the case of a null set, the
SER.E
n
/SERH.E
n
bit remains set. It submits the non-null/non-dummy TR to the associated transfer
controller. If the TR was programmed for early completion, the EDMA3CC immediately sets the
interrupt pending register (IPR.I[TCC]/IPRH.I[TCC]-32).
5. If the TR was programmed for normal completion, the EDMA3CC sets the interrupt pending register
(IPR.I[TCC]/IPRH.I[TCC]) when the EDMA3TC informs the EDMA3CC about completion of the transfer
(returns transfer completion codes).
6. The EDMA3CC programs the associated EDMA3TC
n
's Program Register Set with the TR.
7. The TR is then passed to the Source Active set and the Dst FIFO Register Set, if both the register sets
are available.
8. The Read Controller processes the TR by issuing read commands to the source slave endpoint. The
Read Data lands in the Data FIFO of the EDMA3TC
n
.
9. As soon as sufficient data is available, the Write Controller begins processing the TR by issuing write
commands to the destination slave endpoint.
10. This continues until the TR completes and the EDMA3TC
n
then signals completion status to the
EDMA3CC.
60
EDMA3 Architecture
SPRUG34 – November 2008
Summary of Contents for TMS320DM357
Page 2: ...2 SPRUG34 November 2008 Submit Documentation Feedback ...
Page 12: ...List of Tables 12 SPRUG34 November 2008 Submit Documentation Feedback ...
Page 16: ...Read This First 16 SPRUG34 November 2008 Submit Documentation Feedback ...
Page 64: ...EDMA3 Architecture 64 SPRUG34 November 2008 Submit Documentation Feedback ...