ADSP-214xx SHARC Processor Hardware Reference
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I/O Processor
DMA Transfer Types
Standard DMA.
A standard DMA (once it is configured) transfers data
from location A to location B. An interrupt can be used to indicate the
end of the transfer. To start a new DMA sequence after the current one is
finished, a program must first clear the DMA enable bit (control register),
write new parameters to the index, modify, and count registers (parameter
registers), then set the DMA enable bit to re-enable DMA (control
register).
An instance where standard DMA can be used is to copy data from a
peripheral to internal memory for processor booting. With the help of the
loader tool, the tag (header information) of the boot stream is decoded to
get the storage information which includes the index, modify, and count
of a specific array to start another standard DMA.
Chained DMA
. Chained DMA sequences are a set of multiple DMA
operations, each autoinitializing the next in line. To start a new DMA
sequence after the current one is finished, the IOP automatically loads
new index, modify, and count values from an internal memory location
(or external memory location for DMA to external ports) pointed to by
that channel’s chain pointer register. Using chaining, programs can set up
consecutive DMA operations and each operation can have different
attributes.
Chained DMA with direction on the fly (External Port).
The external
port DMA controller supports chained DMA sequences with an addi-
tional feature that allows the port to change the data direction for each
individual TCB. An additional bit in the TCB differentiates between a
read or write operation.
The IDP port does not support DMA chaining.
Ping-pong DMA (IDP).
In ping-pong DMA, the parameters have two
memory index values (index A and index B), one count value and one
modifier value. The DMA starts the transfer with the memory indexed by
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Содержание SHARC ADSP-214 Series
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Страница 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
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Страница 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...