SPORT Operation Modes
9-32
ADSP-2126x SHARC Processor Hardware Reference
incoming time slot data, while SPORT0, 2, and 4 compress selected out-
going time slot data.
SPORT Loopback
When the SPORT loopback bit,
SPL
bit 12 is set in the
SPMCTL01
,
SPMCTL23
, or
SPMCTL45
control registers, the serial port is configured in an
internal loopback connection as follows: SPORT0 and SPORT1 work as a
pair for internal loopback, SPORT2 and SPORT3 work as pairs, and
SPORT4 and SPORT5 work as pairs. The Loopback mode enables pro-
grams to test the serial ports internally and to debug applications.
When loopback is configured the:
•
SPORTx_DA
,
SPORTx_DB
,
SPORTx_CLK
and
SPORTx_FS
signals of
SPORT0 and SPORT1 are internally connected (where x = 0 or 1)
• The
SPORTy_DA
,
SPORTy_DB
,
SPORTy_CLK
, and
SPORTy_FS
signals of
SPORT2 and SPORT3 are internally connected (where y = 2 or 3)
• The
SPORTz_DA
,
SPORTz_DB
,
SPORTz_CLK
and
SPORTz_FS
signals of
SPORT4 and SPORT5 are internally connected (where z = 4 or 5)
In Loopback mode, either of the two paired SPORTS can be transmitters
or receivers. One SPORT in the loopback pair must be configured as a
transmitter; the other must be configured as a receiver. For example,
SPORT0 can be a transmitter and SPORT1 can be a receiver for internal
loopback. Or, SPORT0 can be a receiver and SPORT1 can be the trans-
mitter when setting up internal loopback. The processor ignores external
activity on the
SPORTx_CLK
,
SPORTx_FS
A and B channel data signals when
the SPORT is configured in Loopback mode. This prevents contention
with the internal loopback data transfer.
Only transmit clock and transmit frame sync options may be used
in loopback mode—programs must ensure that the serial port is set
up correctly in the
SPCTLx
control registers. Multichannel mode is
not allowed. Only Standard DSP Serial, Left-justified Sample Pair,
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 ...