ADSP-2126x SHARC Processor Hardware Reference
10-43
Serial Peripheral Interface Port
Master Mode Core Transfers
When the SPI is configured as a master, the SPI ports should be config-
ured and transfers started using the following steps:
1. When
CPHASE
is set to 0 with
CPHASE
= 1, the slave-selects are auto-
matically controlled by the SPI port. When
CPHASE
= 1, the
slave-selects are controlled by the core, and the user software has to
control the pins through the
SPIFLGx
bits. Before enabling the SPI
port, programs should specify which of the slave-select signals to
use, setting one or more of the required SPI flag select bits (
DSxEN
)
in the
SPIFLGx
registers.
2. Write to the
SPICTLx
and
SPIBAUDx
registers, enabling the device as
a master and configuring the SPI system by specifying the appro-
priate 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 (
SPIFLGx
)
in the
SPIFLGx
registers.
4. Initiate the SPI transfer. The trigger mechanism for starting the
transfer is dependant upon the
TIMOD
bits in the
SPICTLx
registers.
See
5. The SPI generates the programmed clock pulses on
SPICLK
. The
data is shifted out of
MOSI
and shifted in from
MISO
simultaneously.
Before starting to shift, the transmit shift register is loaded with the
contents of the
TXSPIx
registers. At the end of the transfer, the con-
tents of the receive shift register are loaded into the
RXSPIx
registers.
6. With each new transfer initiate command, the SPI continues to
send and receive words, according to the SPI transfer mode (
TIMOD
bit in
SPICTLx
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 ...