
ADSP-214xx SHARC Processor Hardware Reference
3-43
External Port
DMA Access
shows an example of external port DMA using read
optimization.
Listing 3-3. EPDMA With Read Optimization
ustat1=dm(SDCTL);
bit set ustat1 SDROPT|SDMODIFY2;
dm(SDCTL)=ustat1;
nop;
r0=DFLSH;
dm(DMAC1)=r0;
r0=intmem; dm(IIEP1)=r0;
r0=2; dm(IMEP1)=r0;
r0=N; dm(ICEP1)=r0;
r0=2; dm(EMEP1)=r0;
r0=extmem; dm(EIEP1)=r0;
r0=DEN;
dm(DMAC1)=r0;
Notes on Read Optimization
The core and the DMA engine take advantage of the major improvements
during reads using read optimization. However, in situations where both
the core and DMA need to read from different internal memory banks
with different modifiers at the same time, programs need to choose
whether or not to use optimization. Note that from a throughput prospec-
tive, external port arbitration also is a factor. A good rule is that the
requester with the higher priority should have the same modifier as
SDMOD-
IFY
. In other words, if DMA has a higher priority over the core, then the
DMA modifier should match the
SDMODIFY
setting.
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Summary of Contents for SHARC ADSP-214 Series
Page 60: ...Contents lx ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Page 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...