Frame Sync Options
11-56
ADSP-BF535 Blackfin Processor Hardware Reference
When
ITFS
=
1
or
IRFS
=
1
, the corresponding frame sync signal is generated
internally by the SPORT, and the
TFS
pin or
RFS
pin is an output. The
frequency of the frame sync signal is determined by the value of the frame
sync divisor in the
SPORTx_TFSDIV
or
SPORTx_RFSDIV
registers.
When
ITFS
=
0
or
IRFS
=
0
, the corresponding frame sync signal is accepted
as an input on the
TFS
pin or
RFS
pins, and the frame sync divisors in the
SPORTx_TFSDIV
/
SPORTx_RFSDIV
registers are ignored.
All of the frame sync options are available whether the signal is generated
internally or externally.
Active Low Versus Active High Frame Syncs
Frame sync signals may be either active high or active low (in other words,
inverted). The
LTFS
and
LRFS
bits of the
SPORTx_TX_CONFIG
and
SPORTx_RX_CONFIG
registers determine the frame syncs’ logic level:
• When
LTFS
=
0
or
LRFS
=
0
, the corresponding frame sync signal is
active high.
• When
LTFS
=
1
or
LRFS
=
1
, the corresponding frame sync signal is
active low.
Active high frame syncs are the default. The
LTFS
and
LRFS
bits are initial-
ized to 0 after a processor reset.
Sampling Edge for Data and Frame Syncs
Data and frame syncs can be sampled on either the rising or falling edges
of the SPORT clock signals. The
CKFE
bit of the
SPORTx_TX_CONFIG
and
SPORTx_RX_CONFIG
registers selects the driving and sampling edges for the
serial data and frame syncs.
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...