10-10
ADSP-2126x SHARC Processor Hardware Reference
5. The SPI generates the programmed clock pulses on
SPICLK
and
simultaneously shifts data out of
MOSI
and shifts data in from
MISO
.
Before starting to shift, the Transmit Shift register is loaded with
the contents of the
TXSPI
register. At the end of the transfer, the
contents of the Receive Shift register are loaded into
RXSPI
.
6. With each new transfer initiate command, the SPI continues to
send and receive words, according to the SPI Transfer mode (
TIMOD
in
SPICTL
). See
for more details.
Slave Mode Operation
When a device is enabled as a slave, the start of a transfer is triggered by a
transition of the
SPIDS
Select signal to the active state (
LOW
) or by the first
active edge of the clock (
SPICLK
), depending on the state of
CPHASE
.
The following steps illustrate SPI operation in the slave mode:
1. Write to the
SPICTL
register to make the mode of the serial link the
same as the mode that is setup in the SPI master.
2. To prepare for the data transfer, write the data to be transmitted
into the
TXSPI
register.
3. Once the
SPIDS
signal’s falling edge is detected, the slave starts
sending and receiving data on active
SPICLK
edges.
4. The reception or transmission continues until
SPIDS
is released or
until the slave has received the proper number of clock cycles.
5. The slave device continues to receive or transmit with each new
falling-edge transition on
SPIDS
or active
SPICLK
clock edge.
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 ...