Texas Instruments OMAP5912 Reference Manual page 680

System DMA
Table 24. Channel Data Block to Transfer
56 Direct Memory Access (DMA) Support
If the frame size is increased by doubling the element size, EN = 10, the
example is as follows (assumed that the targeted source support 4x32 bits
burst):
A logical channel is set up for a transfer with the following parameters for
its source:
Number of frames in the block: FN = 2 elements.
J
Number of elements per frame: EN = 10 elements.
J
Type of data: s16.
J
Frame index in bytes: FI = 9 bytes.
J
Element index in bytes: EI = 1 byte.
J
Source start address: SA = 14 bytes.
J
Source addressing mode: Double indexed addressing mode.
J
The source port is a 32-bit port with byte/word16/word32/4x32bit burst
J
access capability.
Source packing is enabled.
J
Source burst is enabled.
J
Memory block to transfer is: element i, j (where j is the element number
J
of frame i).
Note that i and j starts with the highest number and decreases, so the
J
first element written is element 2,10.
Table 24 shows the channel blocks to transfer.
Address Byte 0
12
16 Element 2,9
20 Element 2,7
24 Element 2,5
28 Element 2,3
32 Element 2,1
36
40
44 Element 1,9
48 Element 1,7
52 Element 1,5
64 Element 1,3
68 Element 1,1
72
Table 25 lists the computed addresses and access types.
Byte 1 Byte 2 Byte 3
Element 2,10
Element 2,8
Element 2,6
Element 2,4
Element 2,2
Element 1,10
Element 1,8
Element 1,6
Element 1,4
Element 1,2
SPRU755B