Slave Mode Operation (Non-Dma) - Analog Devices ADSP-BF506F Hardware Reference Manual

Functional Description
Table 18-1. Transfer Initiation
TIMOD Function
Transmit and
b#00
receive
Transmit and
b#01
receive
Receive with
b#10
DMA
Transmit with
b#11
DMA

Slave Mode Operation (Non-DMA)

When a device is enabled as a slave (and DMA mode is not selected), the
start of a transfer is triggered by a transition of the SPISS select signal to
the active state (low), or by the first active edge of the clock (SCK),
depending on the state of the CPHA bit in the SPI_CTL register.
18-20
Transfer Initiated Upon
Initiate new single word trans-
fer upon read of SPI_RDBR
and previous transfer com-
pleted.
Initiate new single word trans-
fer upon write to SPI_TDBR
and previous transfer com-
pleted.
Initiate new multiword trans-
fer upon enabling SPI for DMA
mode. Individual word trans-
fers begin with a DMA read of
SPI_RDBR, and last transfer
completed.
Initiate new multiword trans-
fer upon enabling SPI for DMA
mode. Individual word trans-
fers begin with a DMA write to
SPI_TDBR, and last transfer
completed.
ADSP-BF50x Blackfin Processor Hardware Reference
Action, Interrupt
Interrupt is active when the
receive buffer is full.
Read of SPI_RDBR clears
interrupt.
Interrupt is active when the
transmit buffer is empty.
Writing to SPI_TDBR clears
interrupt.
Request DMA reads as long as
the SPI DMA FIFO is not
empty.
Request DMA writes as long as
the SPI DMA FIFO is not full.