ADSP-BF537 Blackfin Processor Hardware Reference
10-15
SPI Compatible Port Controllers
shown for
SCK
—one for
CPOL = 0
and the other for
CPOL = 1
. The dia-
grams may be interpreted as master or slave timing diagrams since the
SCK
,
MISO
, and
MOSI
pins are directly connected between the master and the
slave. The
MISO
signal is the output from the slave (slave transmission),
and the
MOSI
signal is the output from the master (master transmission).
The
SCK
signal is generated by the master, and the
SPISS
signal is the slave
device select input to the slave from the master. The diagrams represent an
8-bit transfer (
SIZE = 0
) with the Most Significant Bit (MSB) first
(
LSBF = 0
). Any combination of the
SIZE
and
LSBF
bits of
SPI_CTL
is
allowed. For example, a 16-bit transfer with the Least Significant Bit
(LSB) first is another possible configuration.
The clock polarity and the clock phase should be identical for the master
device and the slave device involved in the communication link. The
transfer format from the master may be changed between transfers to
adjust to various requirements of a slave device.
When
CPHA = 0
, the slave select line,
SPISS
, must be inactive (high)
between each serial transfer. This is controlled automatically by the SPI
hardware logic. When
CPHA = 1
,
SPISS
may either remain active (low)
between successive transfers or be inactive (high). This must be controlled
by the software via manipulation of
SPI_FLG.
shows the SPI transfer protocol for
CPHA = 0
. Note
SCK
starts
toggling in the middle of the data transfer,
SIZE = 0
, and
LSBF = 0.
shows the SPI transfer protocol for
CPHA = 1
. Note
SCK
starts
toggling at the beginning of the data transfer,
SIZE = 0
, and
LSBF = 0.
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 ...