
SPI Interface Signals
10-6
ADSP-2126x SHARC Processor Hardware Reference
requires these signals to be manually controlled in software via the
SPIDSx
bits in the
SPIFLG
register (the
SPIDSx
bits are ignored when
CPHASE
=0).
SPI Device Select Signal
The
SPIDS
signal is the Serial Peripheral Interface Device Select Input sig-
nal. This is an active low signal used to enable an ADSP-2126x configured
as a slave device. This input-only pin behaves like a chip select, and is pro-
vided by the master device for the slave devices. When the processor is the
SPI-master in a multimaster environment, the
SPIDS
pin acts as an error
signal. In multimaster mode, if the
SPIDS
input signal of a master is
asserted (driven low), an error has occurred. This means that another
device is also trying to be the master device.
Master Out Slave In (MOSI)
The
MOSI
pin is one of the bidirectional I/O data pins. If the processor is
configured as a master, the
MOSI
pin becomes a data transmit (output) pin.
If the processor is configured as a slave, the
MOSI
pin becomes a data
receive (input) pin. In an ADSP-2126x processor SPI interconnection, the
data is shifted out from the
MOSI
output pin of the master and shifted into
the
MOSI
input of the slave.
Master In Slave Out (MISO)
The
MISO
pin is one of the bidirectional I/O data pins. If the ADSP-2126x
is configured as a master, the
MISO
pin becomes a data receive (input) pin.
If the ADSP-2126x is configured as a slave, the
MISO
pin becomes a data
transmit (output) pin. In an SPI interconnection, the data is shifted out
from the
MISO
output pin of the slave and shifted into the
MISO
input pin
of the master.
Only one slave is allowed to transmit data at any given time.
illustrates how the ADSP-2126x can be used as the slave SPI device. The
Содержание ADSP-21261 SHARC
Страница 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Страница 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Страница 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Страница 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Страница 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...