IOP/Core Interaction Options
7-4
ADSP-2126x SHARC Processor Hardware Reference
this is the
IDP_DMAx_STAT
bits of the
DAI_STAT
register can become active
even if DMA, through some IDP channel, is not intended.
The following are some other I/O processor interrupt attributes.
• When an unchained (single block) DMA process reaches comple-
tion (as the count decrements to zero) on any DMA channel, the
I/O processor latches that DMA channel’s interrupt. It does this by
setting the DMA channel’s interrupt latch bit in the
IRPTL
,
LIRPTL
,
DAI_IRPTL_H
, or
DAI_IRPTL_L
registers.
• For chained DMA, the I/O processor generates interrupts in one of
two ways: If
PCI
= 1, an interrupt occurs for each DMA in the
chain; if
PCI
= 0, an interrupt occurs at the end of a complete
chain. (For more information on DMA chaining, see
• When a DMA channel’s buffer is not being used for a DMA pro-
cess, the I/O processor can generate an interrupt on single word
writes or reads of the buffer. This interrupt service differs slightly
for each port. For more information on single word inter-
rupt-driven transfers, see
“Parallel Port Control Register (PPCTL)”
SPCTL
.
During interrupt-driven DMA, programs use the interrupt mask bits in
the
IMASK
,
LIRPTL
,
DAI_IRPTL_PRI
,
DAI_IRPTL_RE
, and
DAI_IRPTL_FE
reg-
isters to selectively mask DMA channel interrupts that the I/O processor
latches into the
IRPTL
,
LIRPTL
,
DAI_IRPTL_H
, and
DAI_IRPTL_L
registers.
The I/O processor only generates a DMA complete interrupt when
the channel’s count register decrements to zero as a result of actual
DMA transfers. Writing zero to a count register does not generate
the interrupt. To stop a DMA preemptively, write a one to the
count register. This causes one more word to be transferred or
received and an interrupt is then generated.
Summary of Contents for ADSP-21261 SHARC
Page 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Page 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Page 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Page 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Page 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Page 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Page 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Page 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Page 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Page 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Page 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Page 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...