Functional Description
10-26
ADSP-BF537 Blackfin Processor Hardware Reference
Slave Mode Operation
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
), depend-
ing on the state of
CPHA
.
These steps illustrate SPI operation in the slave mode:
1. The core writes to the
PORTF_FER
and
PORT_MUX
registers to prop-
erly configure the
PF14
pin as the
SPISS
input signal.
2. The core writes to
SPI_CTL
to define the mode of the serial link to
be the same as the mode setup in the SPI master.
3. To prepare for the data transfer, the core writes data to be trans-
mitted into
SPI_TDBR
.
4. Once the
SPISS
falling edge is detected, the slave starts sending
data on active
SCK
edges and sampling data on inactive
SCK
edges.
10
Receive with
DMA
Initiate new multiword trans-
fer upon enabling SPI for
DMA mode. Individual word
transfers begin with a DMA
read of SPI_RDBR, and last
transfer completed.
Request DMA reads as long as
SPI DMA FIFO is not empty.
11
Transmit with
DMA
Initiate new multiword trans-
fer upon enabling SPI for
DMA mode. Individual word
transfers begin with a DMA
write to SPI_TDBR, and last
transfer completed.
Request DMA writes as long as
SPI DMA FIFO is not full.
Table 10-4. Transfer Initiation (Cont’d)
TIMOD
Function
Transfer Initiated Upon
Action, Interrupt
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...