SPI Registers
18-36
ADSP-BF50x Blackfin Processor Hardware Reference
SPI Control (SPI_CTL) Register
The
SPI_CTL
register is used to configure and enable the SPI system. This
register is used to enable the SPI interface, select the device as a master or
slave, and determine the data transfer format and word size.
The term “word” refers to a single data transfer of either 8 bits or 16 bits,
depending on the word length (
SIZE
) bit in
SPI_CTL
. There are two special
bits which can also be modified by the hardware:
SPE
and
MSTR
.
The
TIMOD
field is used to specify the action that initiates transfers to/from
the receive/transmit buffers. When set to
b#00
, a SPI port transaction is
begun when the receive buffer is read. Data from the first read will need to
be discarded since the read is needed to initiate the first SPI port transac-
tion. When set to
b#01
, the transaction is initiated when the transmit
buffer is written. A value of
b#10
selects DMA receive mode and the first
transaction is initiated by enabling the SPI for DMA receive mode. Subse-
quent individual transactions are initiated by a DMA read of the
SPI_RDBR
register. A value of 11 selects DMA transmit mode and the transaction is
initiated by a DMA write of the
SPI_TDBR
register.
The
PSSE
bit is used to enable the
SPISS
input for an external master.
When not used,
SPISS
can be disabled, freeing up a pin for an alternate
function.
The
EMISO
bit enables the
MISO
pin as an output. This is needed in an
environment where the master wishes to transmit to various slaves at one
time (broadcast). Only one slave is allowed to transmit data back to the
master. Except for the slave from whom the master wishes to receive, all
other slaves should have this bit cleared.
The
SPE
and
MSTR
bits can be modified by hardware when the
MODF
bit of
the
SPI_STAT
register is set. See
“Mode Fault Error (MODF)” on
page 18-41
.
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...