ADSP-2126x SHARC Processor Hardware Reference
7-17
I/O Processor
1. Enter chain insertion mode by setting
SCHEN_A
= 1 and
SDEN_A
= 0
in the channel’s DMA control register,
SPCTL0
. The DMA inter-
rupt indicates when the current DMA sequence has completed.
2. Copy the address currently held in the chain pointer register to the
chain pointer position of the last TCB in the chain that is being
inserted.
3. Write the start address of the first TCB of the new chain into the
chain pointer register.
4. Resume chained DMA mode by setting
SCHEN_A
= 1 and
SDEN_A
= 1.
Chain insertion mode operates the same as non-chained DMA mode.
When the current DMA transfer ends, an interrupt request occurs and no
TCBs are loaded. This interrupt request is independent of the
PCI
bit
state.
Chain insertion should not be set up as an initial mode of opera-
tion. This mode should only be used to insert one or more TCBs
into an active DMA chaining sequence.
Setting Up DMA Channel Allocation and Priorities
The ADSP-2126x processor has 22 DMA channels including 12 channels
accessible via the serial ports, one SPI channel, one parallel port channel,
and eight input data port channels. Each channel has a set of parameter
registers which are used to set up DMA transfers.
shows the
DMA channel allocation and parameter register assignments for the
ADSP-2126x processor. DMA channel 0 has the highest priority and
DMA channel 21 has the lowest priority.
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 ...