ADSP-2126x SHARC Processor Hardware Reference
7-3
I/O Processor
• Input data port (IDP)
4. Enable DMA by setting the applicable bits in the appropriate
registers:
• parallel port –
PPDEN
in
PPCTL
• serial port –
SDEN_x
(
SCHEN_x
for chaining) in
SPCTLx
• SPI –
SPIDEN
(
SPICHEN
for chaining) in
SPIDMAC
• IDP –
IDP_DMA_EN
in the
IDP_CTL
IOP/Core Interaction Options
There are two methods the processor uses to monitor the progress of
DMA operations—interrupts, which are the primary method, and status
polling. The same program can use either method for each DMA channel.
The following sections describe both methods in detail.
Interrupt-Driven I/O
Interrupts on the ADSP-2126x processor are generated at the end of a
DMA transfer. This happens when the count register for a particular
channel decrements to zero. The interrupt vector locations for each of the
channels are listed in
. The interrupt register diagram and bit
descriptions are in and
“DAI Interrupt Controller Registers” on
Programs can check the appropriate status register (for example
PPCTL
for
the parallel port) to determine which channels are performing a DMA or
chained DMA.
All DMA channels can be active or inactive. If a channel is active, a DMA
is in progress on that channel. The I/O processor indicates the active sta-
tus by setting the channel’s bit in the status register. The only exception to
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 ...