Sorting Example In Order Of Dma Transfers - Texas Instruments TMS320C6201 Reference Manual

Address Generation
5.7.6 Sorting
Table 5–7. Sorting Example in Order of DMA Transfers
5-26
The following procedure is used to locate transfers in memory by ordinal loca-
tion within a frame (i.e., the first transfer of the first frame followed by the first
transfer of the second frame):
ELEMENT INDEX is set to F
FRAME INDEX is set to –(((E – 1)
where:
E = Initial value of ELEMENT COUNT (the number of elements
per frame) initial value of the ELEMENT COUNT RELOAD
F = Initial value of FRAME COUNT (the total number of frames)
S = Element size in bytes
Consider a transfer with three frames (F = 3) of four halfword elements
each (E = 4, S = 2). This corresponds to ELEMENT INDEX = 3 2 = 6 and
FRAME INDEX = –(((4 – 1) 3) – 1) 2 = FFF0h. Assume that the source
address is not modified and the destination increments starting at
8000 0000h. Table 5–7 shows the data in the order in which it is trans-
ferred, and Table 5–8 shows how the data appears in memory after trans-
fers are finished.
Frame Element
0
0
0
0
1
1
1
1
2
2
2
2
S.
F) – 1)
Address (Hex)
0 8000 0000
1 8000 0006
2 8000 000C
3 8000 0012
0 8000 0002
1 8000 0008
2 8000 000E
3 8000 0014
0 8000 0004
1 8000 000A
2 8000 0010
3 8000 0016
S
Postadjustment
+6
+6
+6
–16
+6
+6
+6
–16
+6
+6
+6
–16