Programming Models
3-124
ADSP-214xx SHARC Processor Hardware Reference
interrupt is generated at the end of each delay line DMA block or at the
end of entire chained DMA, depending on the
PCI
bit setting.
When delay line DMA is enabled with chaining, all the chained
DMA blocks follow the delay line DMA access procedure. It is not
possible to mix normal DMA with delay line DMA in chained
DMA.
Disabling and Re-enabling DMA
Use the following programming model to disable the external port DMA
during transfers.
1. Clear the
DMAEN
bit on the
DMACx
register.
2. Wait until the
EXTS
bit is 0.
3. Write 0x0 to the
ICEP
and
DMACx
registers. In cases where DMA is
used without chaining, writing to
ICEP
is not required.
4. Re-initialize the required DMA registers, and enable the
DMACx
reg-
ister while flushing the data/tap list FIFO.
Additional Information
1. If DMA is disabled in the middle of a data transfer, then DMA
interrupts cannot be relied on.
2. A single DMA (no chaining) can be stopped midway by clearing
the
DMAEN
bit in the
DMACx
register and then restarted from the
point where it was stopped by re-enabling the
DMAEN
bit. This mode
of inhibiting the DMA only works with single DMA. If a
chained/delay line DMA is disabled by clearing
DMAEN
bit then the
DMA should be reprogrammed again following the above pro-
gramming model.
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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...
Страница 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
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...