Descriptor Based DMA
9-4
ADSP-BF535 Blackfin Processor Hardware Reference
DMA Descriptor Block Structure
The elements of a DMA descriptor block are defined in
Table 9-1
, where
BASE
refers to the starting address of the descriptor block.
The processor can place multiple sets of descriptor blocks, representing
multiple transfers, in memory. A set of descriptor blocks is called a
linked
list
(see
Figure 9-1
). When a linked list has been generated, the DMA
channel has all the information needed to perform multiple transfer
sequences without processor intervention.
Figure 9-1. Linked List Containing Two Descriptor Blocks
CONFIGURATION WORD A
A + 0
DESCRIPTOR BLOCK
A
TRANSFER COUNT A
A + 2
START ADDRESS[15:0]
A + 4
START ADDRESS[31:16]
A + 6
B + 0
A + 8
B + 0
DESCRIPTOR BLOCK
B
B + 2
B + 4
B + 6
B + 8
DMA_END
0
X
0001
LINKED LIST
CONFIGURATION WORD B
TRANSFER COUNT B
START ADDRESS[15:0]
START ADDRESS[31:16]
DMA_END
Summary of Contents for ADSP-BF535 Blackfin
Page 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Page 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Page 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Page 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Page 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Page 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Page 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Page 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Page 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...