Functional Description
The transfer completion code (TCC) value is directly mapped to the bits of the interrupt pending register
(IPR/IPRH). For example, if TCC = 10 0001b, IPRH[1] is set after transfer completion, and results in
interrupt generation to the CPU(s) if the completion interrupt is enabled for the CPU. See
for details on enabling EDMA3 transfer completion interrupts.
When a completion code is returned (as a result of early or normal completions), the corresponding bit in
IPR/IPRH is set if transfer completion interrupt (final/intermediate) is enabled in the channel options
parameter (OPT) for a PaRAM set associated with the transfer.
Table 11-15. Transfer Complete Code (TCC) to EDMA3CC Interrupt Mapping
TCC Bits in OPT
TCC Bits in OPT
IPR Bit Set
IPRH Bit Set
(1)
(TCINTEN/ITCINTEN = 1)
(TCINTEN/ITCINTEN = 1)
0
IPR0
20h
IPR32/IPRH0
1
IPR1
21h
IPR33/IPRH1
2h
IPR2
22h
IPR34/IPRH2
3h
IPR3
23h
IPR35/IPRH3
4h
IPR4
24h
IPR36/IPRH4
...
...
...
...
1Eh
IPR30
3Eh
IPR62/IPRH30
1Fh
IPR31
3Fh
IPR63/IPRH31
(1)
Bit fields IPR[32-63] correspond to bits 0 to 31 in IPRH, respectively.
You can program the transfer completion code (TCC) to any value for a DMA/QDMA channel. A direct
relation between the channel number and the transfer completion code value does not need to exist. This
allows multiple channels having the same transfer completion code value to cause a CPU to execute the
same interrupt service routine (ISR) for different channels.
If the channel is used in the context of a shadow region and you intend for the shadow region interrupt to
be asserted, then ensure that the bit corresponding to the TCC code is enabled in IER/IERH and in the
corresponding shadow region's DMA region access registers (DRAE/DRAEH).
You can enable Interrupt generation at either final transfer completion or intermediate transfer completion,
or both. Consider channel m as an example.
•
If the final transfer interrupt (TCCINT = 1 in OPT) is enabled, the interrupt occurs after the last transfer
request of channel m is either submitted or completed (depending on early or normal completion).
•
If the intermediate transfer interrupt (ITCCINT = 1 in OPT) is enabled, the interrupt occurs after every
transfer request, except the last TR of channel m is either submitted or completed (depending on early
or normal completion).
•
If both final and intermediate transfer completion interrupts (TCCINT = 1, and ITCCINT = 1 in OPT) are
enabled, then the interrupt occurs after every transfer request is submitted or completed (depending on
early or normal completion).
shows the number of interrupts that occur in different synchronized scenarios. Consider
channel 31, programmed with ACNT = 3, BCNT = 4, CCNT = 5, and TCC = 30.
Table 11-16. Number of Interrupts
Options
A-Synchronized
AB-Synchronized
TCINTEN = 1, ITCINTEN = 0
1 (Last TR)
1 (Last TR)
TCINTEN = 0, ITCINTEN = 1
19 (All but the last TR)
4 (All but the last TR)
TCINTEN = 1, ITCINTEN = 1
20 (All TRs)
5 (All TRs)
903
SPRUH73H – October 2011 – Revised April 2013
Enhanced Direct Memory Access (EDMA)
Copyright © 2011–2013, Texas Instruments Incorporated