Programming Examples; Register-Based 2-D Memory Dma - Analog Devices ADSP-BF506F Hardware Reference Manual

Programming Examples

direction DCB accesses are treated preferentially. When this count decre-
ments from 1 to 0, the opposite direction DCB access is treated
preferentially, which may result in a direction change. When this count is
0 and a DCB bus access occurs, the count is reloaded from
DCB_TRAFFIC_PERIOD
Programming Examples
The following examples illustrate memory DMA and handshaked memory
DMA basics. Examples for peripheral DMAs can be found in the respec-
tive peripheral chapters.

Register-Based 2-D Memory DMA

Listing 7-1 shows a register-based, two-dimensional MDMA. While the
source channel processes linearly, the destination channel re-sorts ele-
ments by transposing the two-dimensional data array. See
Figure 7-27. DMA Example, 2-D Array
The two arrays reside in two different L1 data memory blocks. However,
the arrays could reside in any internal or external memory, including L1
instruction memory and SDRAM. For the case where the destination
array resided in SDRAM, it is a good idea to let the source channel re-sort
elements and to let the destination buffer store linearly.
7-92
to begin a new burst.
1 7 13 19 25
2 8 14 20 26
3 9 15 21 27
4 10 16 22 28
5 11 17 23 29
6 12 18 24 30
ADSP-BF50x Blackfin Processor Hardware Reference
Figure
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
25 26 27 28 29 30
7-27.