ADSP-2126x SHARC Processor Hardware Reference
9-27
Serial Ports
The
SPORT0_FS
,
SPORT2_FS
or
SPORT4_FS
is used as a transmit data valid
signal, which is active during transmission of an enabled word. Because
the serial port’s
SPORT0_DA/B
,
SPORT2_DA/B
and
SPORT4_DA/B
signals are
three-stated when the time slot is not active, the
SPORT0_FS/SPORT2_FS/SPORT4_FS
signal specifies if
SPORT0_DA/B/SPORT2_DA/B/SPORT4_DA/B
is being driven by the processor.
The
SPORT0_FS
signal is renamed
TDV01
. The
SPORT2_FS
signal is renamed
TDV23
and the
SPORT4_FS
signal is renamed
TDV45
in multichannel mode.
These signals become outputs. Do not connect
SPORT2_FS
(
TDV23
) to
SPORT0_FS
, and
SPORT4_FS
(
TDV45
) to
SPORT1_FS
in multichannel mode.
Bus contention between the transmit data valid and multichannel frame
sync signals will result.
After the
TXSPxA
transmit buffer is loaded, transmission begins and the
SPORT0_FS
,
SPORT2_FS/SPORT4_FS
signal is generated. When serial port
DMA is used, this may occur several cycles after the multichannel trans-
mission is enabled. If a deterministic start time is required, pre-load the
transmit buffer.
Active State Multichannel Receive Frame Sync Select
The
LRFS
bit in the
SPCTL1
,
SPCTL3
, and
SPCTL5
registers selects the logic
level of the multichannel received frame sync signals as active low
(inverted) if set (=1) or active high if cleared (=0). Active high (=0) is the
default.
Multichannel Mode Control Bits
Several bits in the
SPCTLx
Control register enable and configure multi-
channel mode operation:
• Operation mode (
OPMODE
)
• Word length (
SLEN
)
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 ...