Functional Description
10-24
ADSP-BF537 Blackfin Processor Hardware Reference
Master Mode Operation
When the SPI is configured as a master (and DMA mode is not selected),
the interface operates in the following manner.
1. The core writes to the
PORTF_FER
and/or
PORT_MUX
registers to
properly configure the required
PFx
and/or
PJx
pins for SPI use as
slave-select outputs and, if necessary, multimaster detection input
(
SPISS
).
2. The core writes to
SPI_FLG
, setting one or more of the SPI Flag
Select bits (
FLSx
). This ensures that the desired slaves are properly
deselected while the master is configured.
3. The core writes to the
SPI_BAUD
and
SPI_CTL
registers, enabling the
device as a master and configuring the SPI system by specifying the
appropriate word length, transfer format, baud rate, and other nec-
essary information.
4. If
CPHA = 1
, the core activates the desired slaves by clearing one or
more of the SPI flag bits (
FLGx
) of
SPI_FLG
.
5. The
TIMOD
bits in
SPI_CTL
determine the SPI transfer initiate
mode. The transfer on the SPI link begins upon either a data write
by the core to the transmit data buffer
(
SPI_TDBR
) or a data read of
the receive data buffer (
SPI_RDBR
).
6. The SPI then generates the programmed clock pulses on
SCK
and
simultaneously shifts data out of
MOSI
and shifts data in from
MISO
.
Before a shift, the shift register is loaded with the contents of the
SPI_TDBR
register. At the end of the transfer, the contents of the
shift register are loaded into
SPI_RDBR
.
7. With each new transfer initiate command, the SPI continues to
send and receive words, according to the SPI transfer initiate mode.
See
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 ...