ADSP-2126x SHARC Processor Hardware Reference
9-69
Serial Ports
Load the
II
,
IM
, and
C
registers with a starting address for the buffer, an
address modifier, and a word count, respectively. These registers can be
written from the core processor or from an external processor.
Once serial port DMA is enabled, the processor’s DMA controller auto-
matically transfers received data words in the receive buffer to the buffer
in internal memory. Likewise, when the serial port is ready to transmit
data, the DMA controller automatically transfers a word from internal
memory to the transmit buffer. The controller continues these transfers
until the entire data buffer is received or transmitted.
When the count register of an active DMA channel reaches zero (0), the
SPORT generates the corresponding interrupt.
SPORT DMA Parameter Registers
A DMA channel consists of a set of parameter registers that implements a
data buffer in internal memory and the hardware the serial port uses to
request DMA service. The parameter registers for each SPORT DMA
channel and their addresses are shown in
below. These regis-
ters are part of the processor’s memory-mapped IOP register set.
The DMA channels operate similarly to the processor’s Data Address
Generators (DAGs). Each channel has an Index register (
IISPxy
) and a
Table 9-9. SPORT DMA Parameter Registers
Register
(Y = A or B, and x = 0 – 5)
Width
Description
IISPxy
19 bits
DMA channel; x index; start address for data buffer
IMSPxy
16 bits
DMA channel; x modify; address increment
CSPxy
16 bits
DMA channel; x count; number of words to trans-
mit
CPSPxy
20 bits
DMA channel; x chain pointer; address containing
the next set of data buffer parameters
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 ...