ADSP-BF537 Blackfin Processor Hardware Reference
5-3
Direct Memory Access
set of parameters stored within memory to initiate a DMA sequence. This
sort of transfer allows the chaining together of multiple DMA sequences.
In descriptor-based DMA operations, a DMA channel can be pro-
grammed to automatically set up and start another DMA transfer after the
current sequence completes.
Examples of DMA styles supported by flex descriptors include:
• A single linear buffer that stops on completion (
FLOW
= stop mode)
• A linear buffer with strides equal 1 or greater, zero or negative
(
DMAx_X_MODIFY
register)
• A circular, auto-refreshing buffer that interrupts on each full buffer
• A similar buffer that interrupts on fractional buffers (for example,
1/2, 1/4) (2D DMA)
• 1D DMA, using a set of identical ping-pong buffers defined by a
linked ring of 3-word descriptors, each containing { link pointer,
32-bit address }
• 1D DMA, using a linked list of 5-word descriptors containing
{ link pointer, 32-bit address, length, config } (ADSP-2191 style)
• 2D DMA, using an array of 1-word descriptors, specifying only the
base DMA address within a common data page
• 2D DMA, using a linked list of 9-word descriptors, specifying
everything
The following 16 functions can be served by DMA channels:
• PPI receive/transmit
• Ethernet receive (not present on ADSP-BF534)
• Ethernet transmit (not present on ADSP-BF534)
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...