Parameter set 0
PaRAM
Set
#
Byte
address
0
EDMA Base A 4000h
EDMA Base A 4020h
1
Parameter set 1
EDMA Base A 4040h
2
Parameter set 2
EDMA Base A 4060h
3
Parameter set 3
EDMA Base A 5FC0h
EDMA Base A 5FE0h
254
255
Parameter set 255
Parameter set 254
OPT X
SRC X
BCNT X
ACNT X
DST X
SRCBIDX X
DSTBIDX X
Link X=5FE0h
BCNTRLD X
CCNT X
SRCCIDX X
DSTCIDX X
Rsvd
PaRAM set 3
PaRAM set 255
EDMA Base A 5FC0h
EDMA Base A 5FE0h
254
255
Parameter set 254
Parameter set 255
Parameter set 0
0
EDMA Base A 4000h
EDMA Base A 4040h
EDMA Base A 4060h
EDMA Base A 4020h
2
3
1
Parameter set 1
Parameter set 2
Parameter set 3
Byte
address
Set
#
PaRAM
PaRAM set 3
(a)
At initialization
(b)
After completion of PaRAM set 3
(link update)
Link
copy
EDMA Base A 5FC0h
254
Parameter set 254
Parameter set 0
0
EDMA Base A 4000h
EDMA Base A 4040h
EDMA Base A 4060h
EDMA Base A 4020h
2
3
1
Parameter set 1
Parameter set 2
Parameter set 3
Byte
address
Set
#
PaRAM
0h
0h
Link=FFFFh
0h
0h
0h
0h
0h
0h
0h
0h
0h
PaRAM set 3 (Null PaRAM set)
0h
EDMA Base A 5FE0h
255
Parameter set 255
(c)
After completion of PaRAM set 51
1
(link to null set)
OPT Y
SRC Y
BCNT Y
ACNT Y
DST Y
SRCBIDX Y
DSTBIDX Y
Link Y=FFFFh
BCNTRLD Y
CCNT Y
SRCCIDX Y
DSTCIDX Y
Rsvd
OPT Y
SRC Y
BCNT Y
ACNT Y
DST Y
SRCBIDX Y
DSTBIDX Y
Link Y=FFFFh
BCNTRLD Y
CCNT Y
SRCCIDX Y
DSTCIDX Y
Rsvd
PaRAM set 255
OPT Y
SRC Y
BCNT Y
ACNT Y
DST Y
SRCBIDX Y
DSTBIDX Y
Link Y=FFFFh
BCNTRLD Y
CCNT Y
SRCCIDX Y
DSTCIDX Y
Rsvd
Functional Description
11.3.3.9 Element Size
The EDMA3 controller does not use element-size and element-indexing. Instead, all transfers are defined
in terms of all three dimensions: ACNT, BCNT, and CCNT. An element-indexed transfer is logically
achieved by programming ACNT to the size of the element and BCNT to the number of elements that
need to be transferred. For example, if you have 16-bit audio data and 256 audio samples that must be
transferred to a serial port, you can only do this by programming the ACNT = 2 (2 bytes) and BCNT = 256.
Figure 11-11. Linked Transfer
892
Enhanced Direct Memory Access (EDMA)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated