ADSP-BF535 Blackfin Processor Hardware Reference
10-37
SPI Compatible Port Controllers
When enabling the
MODF
feature, the program must configure as inputs all
of the
PFx
pins that will be used as slave selects. Programs can do this by
writing to the Flag Direction register (
FIO_DIR)
prior to configuring the
SPI. This ensures that, once the
MODF
error occurs and the slave selects are
automatically reconfigured as
PFx
pins, the slave select output drivers are
disabled.
Transmission Error (TXE)
The
TXE
bit is set in
SPIx_ST
when all the conditions of transmission are
met, but there is no new data in
SPIx_TDBR
(
SPIx_TDBR
is empty). In this
case, the contents of the transmission depend on the state of the
SZ
bit in
SPIx_CTL
. The
TXE
bit is sticky (W1C).
Reception Error (RBSY)
The
RBSY
flag is set in
SPIx_ST
when a new transfer is completed before
the previous data can be read from
SPIx_RDBR
. The state of the
GM
bit in
SPIx_CTL
determines whether
SPIx_RDBR
is updated with the newly
received data. The
RBSY
bit is sticky (W1C).
Transmit Collision Error (TXCOL)
The
TXCOL
flag is set in
SPIx_ST
when a write to
SPIx_TDBR
coincides with
the load of the shift register. The write to
SPIx_TDBR
can be via software or
the DMA. The
TXCOL
bit indicates that corrupt data may have been loaded
into the shift register and transmitted. In this case, the data in
SPIx_TDBR
may not match what was transmitted. This error can easily be avoided by
proper software control. The
TXCOL
bit is sticky (W1C).
The
TXCOL
bit is never set when the SPI is configured as a slave with
CPHA
= 0
. A collision may occur, but it cannot be detected.
Summary of Contents for ADSP-BF535 Blackfin
Page 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Page 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Page 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Page 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Page 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Page 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Page 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Page 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Page 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Page 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Page 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...