A.1
Debug Checklist
Appendix A
SPRUG34 – November 2008
Tips
This section lists some tips to keep in mind while debugging applications using the EDMA3.
provides some common issues and their probable causes and resolutions.
Table A-1. Debug List
Issue
Description/Solution
The transfer associated with the channel
The EDMA3 channel controller (EDMA3CC) may not service a transfer request, even
does not happen. The channel does not
though the associated PaRAM set is programmed appropriately. Check for the
get serviced.
following:
1.
Verify that events are enabled, that is, if an external/peripheral event is latched in
the event registers (ER/ERH), make sure that the event is enabled in the event
enable registers (EER/EERH). Similarly for QDMA channels, make sure that
QDMA events are appropriately enabled in the QDMA event enable register
(QEER).
2.
Verify that the DMA or QDMA secondary event register (SER/SERH/QSERH) bits
corresponding to the particular event or channel are not set.
The secondary event register bits are set,
It is possible that a trigger event was received when the parameter set associated with
not allowing additional transfers to occur
the channel/event was a NULL set for a previous transfer on the channel. This is
on a channel.
typical in two cases:
1.
QDMA channels: Typically if the parameter set is nonstatic and expected to be
terminated by a NULL set (OPT.STATIC = 0, LINK = FFFFh), the parameter set is
updated with a NULL set after submission of the last TR. Because QDMA channels
are autotriggered, this update caused the generation of an event. An event
generated for a NULL set causes an error condition and results in setting the bits
corresponding to the QDMA channel in QEMR and QSER. This will disable further
prioritization of the channel.
2.
DMA channels used in a continuous mode: The peripheral may be set up to
continuously generate infinite events (for instance, in case of the ASP, every time
the data shifts out from the DXR register, it generates an XEVT). The parameter
set may be programmed to expect only a finite number of events and to be
terminated by a NULL link. After the expected number of events, the parameter set
is reloaded with a NULL parameter set. Because the peripheral will generate
additional events, an error condition is set in SER.E
n
and EMR.E
n
, preventing
further event prioritization.
You must ensure that the number of events received is limited to the expected
number of events for which the parameter set is programmed, or you must ensure
that bits corresponding to a particular channel or event are not set in the secondary
event registers (SER/SERH/QSER) and the event missed registers
(EMR/EMRH/QEMR) before trying to perform subsequent transfers for the
event/channel.
SPRUG34 – November 2008
Tips
163
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 ...