ADSP-BF535 Blackfin Processor Hardware Reference
10-11
SPI Compatible Port Controllers
The
SPIx_FLG
register consists of two sets of bits that function as follows.
• Slave Select Enable (
FLSx
) bits
• Each
FLSx
bit corresponds to a Programmable Flag (
PFx
) pin.
When an
FLSx
bit is set, the corresponding
PFx
pin is driven as a
slave select. For example, if
FLS1
is set in
SPI0_FLG
,
PF2
is driven as
a slave select (
SPI0SEL1
).
Table 10-5
and
Table 10-6
show the asso-
ciation of the
FLSx
bits and the corresponding
PFx
pins.
• If the
FLSx
bit is not set, the general-purpose programmable flag
registers (
FIO_DIR
and others) configure and control the corre-
sponding
PFx
pin.
• Slave Select Value (
FLGx
) bits
• When a
PFx
pin is configured as a slave select output, the
FLGx
bits
can determine the value driven onto the output. If the
CPHA
bit in
SPIx_CTL
is set, the output value is set by software control of the
FLGx
bits. The SPI protocol permits the slave select line to either
remain asserted (low) or be deasserted between transferred words.
The user must set or clear the appropriate
FLGx
bits. For example,
to drive
PF3
as a slave select,
FLS1
in
SPI1_FLG
must be set. Clearing
FLG1
in
SPI1_FLG
drives
PF3
low; setting
FLG1
drives
PF3
high. The
PF3
pin can be cycled high and low between transfers by setting
and clearing
FLG1
. Otherwise,
PF3
remains active (low) between
transfers.
Table 10-4. SPIx Flag Register MMR Assignments
Register Name
Memory-Mapped Address
SPI0_FLG
0xFFC0 3002
SPI1_FLG
0xFFC0 3402
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...