ADSP-2126x SHARC Processor Hardware Reference
9-33
Serial Ports
and I
2
S modes support internal loopback. In loopback, each
SPORT can be configured as transmitter or receiver, and each one
is capable of generating internal frame sync and clock.
Any of the three paired SPORTs can be set up to transmit or receive,
depending on their
SPTRAN
bit configurations.
Clock Signal Options
Each serial port has a clock signal (
SPORTx_CLK
) for transmitting and
receiving data on the two associated data signals. The clock signals are
configured by the
ICLK
and
CKRE
bits of the
SPCTLx
Control registers. A
single clock signal clocks both A and B data signals (either configured as
inputs or outputs) to receive or transmit data at the same rate.
The serial clock can be independently generated internally or input from
an external source. The
ICLK
bit of the
SPCTLx
Control registers deter-
mines the clock source.
When
ICLK
is set (=1), the clock signal is generated internally by the pro-
cessor and the
SPORTx_CLK
signals are outputs. The clock frequency is
determined by the value of the serial clock divisor (
CLKDIV
) in the
DIVx
registers.
When
ICLK
is cleared (=0), the clock signal is accepted as an input on the
SPORTx_CLK
signals, and the serial clock divisors in the
DIVx
registers are
ignored. The externally-generated serial clock does not need to be syn-
chronous with the processor system clock. Refer 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 ...