SPORT Control Registers and Data Buffers
9-60
ADSP-2126x SHARC Processor Hardware Reference
Transmit and Receive Data Buffers
The transmit buffers (
TXSP0A
,
TXSP0B
,
TXSP1A
,
TXSP1B
,
TXSP2A
,
TXSP2B
,
TXSP3A
,
TXSP3B
,
TXSP4A
,
TXSP4B
,
TXSP5A,
and
TXSP5B
) are the 32-bit trans-
mit data buffers for SPORT0, SPORT1, SPORT2, SPORT3, SPORT4,
and SPORT5 respectively. These buffers must be loaded with the data to
be transmitted if the SPORT is configured to transmit on the A and B
channels. The data is loaded automatically by the DMA controller or
loaded manually by the program running on the processor core.
The receive buffers (
RXSP0A
,
RXSP0B
,
RXSP1A
,
RXSP1B
,
RXSP2A
,
RXSP2B
,
RXSP3A,
RXSP3B
,
RXSP4A
,
RXSP4B
,
RXSP5A,
and
RXSP5B
) are the 32-bit
receive data buffers for SPORT0, SPORT1, SPORT2, SPORT3,
SPORT4, and SPORT5 respectively. These 32-bit buffers become active
when the SPORT is configured to receive data on the A and B channels.
When a SPORT is configured as a receiver, the
RXSPxA
and
RXSPxB
regis-
ters are automatically loaded from the receive shifter when a complete
word has been received. The data is then loaded to internal memory by the
DMA controller or read directly by the program running on the processor
core.
Word lengths of less than 32 bits are automatically right-justified
in the receive and transmit buffers.
The transmit buffers act like a two-location FIFO because they have a data
register plus an Output Shift register. Two 32-bit words may both be
stored in the transmit queue at any one time. When the transmit register is
loaded and any previous word has been transmitted, the register contents
are automatically loaded into the output shifter. An interrupt occurs when
the Output Transmit shifter has been loaded, signifying that the transmit
buffer is ready to accept the next word (for example, the transmit buffer is
not full). This interrupt does not occur when serial port DMA is enabled
or when the corresponding mask bit in the
LIRPTL
register is set.
In non-Multichannel modes (I
2
S, Left-justified Sample Pair, and DSP
Standard Serial modes), the
ROVF_A
or
TUVF_A
and
ROVF_B
, or
TUVF_B
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 ...