Texas Instruments OMAP5912 Reference Manual page 1113

SPI Master/Slave
Figure 12. DMA Transmit and Receive Protocol in Slave Mode With CIi = 0, CEi = 0
and CPi = 0
DMA write
SPI_TX
SPI_CTRL
SPEN0
1
SRCLK
SPI_SR
dNB
TSPDO
dNB
TSPDI
TSPDOEN
RX_ndma_req
TX_ndma_req
A
SPI_DSR
SPI_RX
A: TX_EMPTY = 1 and RX_FULL = 0
B: TX_EMPTY = 0 and RX_FULL = 0
C: TX_EMPTY = 1 and RX_FULL = 1
48 Serial Interfaces
DMA read on SPI_RX register
WRITE DATA 1
NB+1
READ DATA1
d0
d0
B C
READ DATA 1
DMA write DMA read on SPI_RX register
WRITE DATA 2
RD = 1; WR = 1
NB+1
1
dNB
d0
dNB
d0
A B
MCU-DSP write
RD = 0; WR = 0
READ DATA2
C A
READ DATA 2
SPRU760B