ADSP-2126x SHARC Processor Hardware Reference
10-17
Serial Peripheral Interface Port
Slave Mode DMA Operation
A Slave mode DMA transfer occurs when the SPI port is enabled and con-
figured in Slave mode, and DMA is enabled. When the
SPIDS
signal
transitions to the active-low state or when the first active edge of
SPICLK
is
detected, it triggers the start of a transfer.
To configure for Slave mode DMA:
1. Write to the
SPICTL
register to make the mode of the serial link the
same as the mode that is set up in the SPI master. Configure the
TIMOD
field to select transmit or receive DMA mode
(
TIMOD
= 10).
2. Define a DMA receive (or transmit) transfer by writing to the
IISPI
,
IMSPI
, and
CSPI
registers. For DMA chaining, write to the
chain pointer address of the
CPSPI
register.
10
Transmit or
Receive with
DMA
Initiate new multiword
transfer upon write to
DMA Enable bit. Individ-
ual word transfers begin
with either a DMA write
to TXSPI or a DMA read
of RXSPI depending on
the direction of the trans-
fer as specified by the
SPIRCV bit.
If chaining is disabled, the SPI inter-
rupt is latched in the cycle when the
DMA count decrements from 1 to 0.
If chaining is enabled, interrupt func-
tion is based on the PCI bit in the CP
register. If PCI = 0, the SPI interrupt
is latched at the end of the DMA
sequence. If PCI = 1, then the SPI
interrupt is latched after each DMA
in the sequence.
tion, see “DMA Transfer Direction”
on page 7-21.
11
Reserved
Table 10-1. Transfer Initiation (Cont’d)
TIMOD
Function
Transfer Initiated Upon
Action, Interrupt
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 ...