
Frame Sync Options
9-38
ADSP-2126x SHARC Processor Hardware Reference
Data-Independent Frame Sync
When transmitting data out of the SPORT (
SPTRAN
= 1), the inter-
nally-generated frame sync signal normally is output-only when the
transmit buffer has data ready to transmit. The Data-Independent Frame
Sync (
DIFS
) mode allows the continuous generation of the
SPORTx_FS
sig-
nal, with or without new data in the register. The
DIFS
bit of the
SPCTLx
Control register configures this option.
When
SPTRAN
= 1, the
DIFS
bit selects whether the serial port uses a
data-independent
transmit
frame sync (sync at selected interval, if set to 1)
or a data-dependent transmit frame sync. When
SPTRAN
= 0, this bit selects
whether the serial port uses a data-independent
receive
frame sync or a
data-dependent receive frame sync.
When
DIFS
= 0 and
SPTRAN
= 1, the internally-generated transmit frame
sync is only output when a new data word has been loaded into the
SPORT channel’s transmit buffer. Once data is loaded into the transmit
buffer, it is not transmitted until the next frame sync is generated. This
mode of operation allows data to be transmitted only at specific times.
When
DIFS
= 0 and
SPTRAN
= 0, a receive
SPORTx_FS
signal is generated
only when receive data buffer status is not full.
Figure 9-7. Normal Versus Alternate Framing
B3
B2
B1
B0
...
SPORTX_CLK
LATE
FRAME
SYNC
DATA
EARLY
FRAME
SYNC
Summary of Contents for ADSP-21261 SHARC
Page 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Page 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Page 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Page 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Page 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Page 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Page 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Page 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Page 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Page 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Page 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Page 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...