Functional Description
5-34
ADSP-BF537 Blackfin Processor Hardware Reference
• Descriptor chain indicates data buffers that are not in the same
internal/external memory space.
• In 2D DMA,
X_COUNT = 1
.
DMA Control Commands
Advanced peripherals, such as the ADSP-BF536/ADSP-BF537 processor’s
Ethernet MAC module, are capable of managing some of their own DMA
operations, thus dramatically improving real-time performance and reliev-
ing control and interrupt demands on the Blackfin processor core. These
peripherals may communicate to the DMA controller using DMA control
commands, which are transmitted from the peripheral to the associated
DMA channel over internal DMA request buses. These request buses con-
sist of three wires per DMA-management-capable peripheral. The DMA
control commands extend the set of operations available to the peripheral
beyond the simple “request data” command used by peripherals in
general.
Note that while these DMA control commands are not visible to or con-
trollable by the user, their use by a peripheral has implications for the
structure of the DMA transfers which that peripheral can support. It is
important that application software be written to comply with certain
Table 5-3. Legal NDSIZE Values
FLOW
NDSIZE
Note
0
0
1
0
4
0 < NDSIZE <= 7
Descriptor array, no descriptor pointer fetched
6
0 < NDSIZE <= 8
Descriptor list, small descriptor pointer fetched
7
0 < NDSIZE <= 9
Descriptor list, large descriptor pointer fetched
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 ...