ADSP-2126x SHARC Processor Hardware Reference
10-9
Serial Peripheral Interface Port
resistor is required on both the
MOSI
and
MISO
pins when this option is
selected.
When the
OPD
is set and the SPI port is configured as a master, the
MOSI
pin is three-stated when the data driven out on
MOSI
is logic-high. The
MOSI
pin is not three-stated when the driven data is logic-low. A zero is
driven on the
MOSI
pin in this case. Similarly, when
OPD
is set and the SPI
port is configured as a slave, the
MISO
pin is three-stated if the data driven
out on
MISO
is logic-high.
Master Mode Operation
When the SPI is configured as core master (and DMA mode is not
selected), the SPI port should be configured and transfers started using the
following steps:
1. When
CPHASE
is set to 0, the slave selects are automatically con-
trolled by the SPI port. Otherwise [
CPHASE
= 1] the slave selects are
controlled by the core, and user software controls the pins through
the
SPIFLGx
bits. Before enabling the SPI port, programs should
specify which slave-select signal to use by writing to the
SPIFLG
reg-
ister, setting one or more of the SPI Flag Select bits (
DSxEN
).
2. Write to the
SPICTL
and
SPIBAUD
registers, enabling the device as a
master and configuring the SPI system by specifying the appropri-
ate word length, transfer format, baud rate, and other necessary
information.
3. If
CPHASE
= 1 (user-controlled slave-select signals), activate the
desired slaves by clearing one or more of the SPI flag bits (
SPIFLG
)
in the
SPIFLG
register.
4. Initiate the SPI transfer. The trigger mechanism for starting the
transfer is dependant upon the
TIMOD
bits in the
SPICTL
register.
See
for details.
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 ...