SPORT Operation Modes
9-30
ADSP-2126x SHARC Processor Hardware Reference
The
SPCTL0
,
SPCTL2
,
SPCTL4
Bit 29 (
TUVF_A
). The Transmit Underflow
Status (sticky, read-only) bit indicates (if set, =1) if the multichannel
SPORTx_FS
signal (from internal or external source) occurred while the
TXS
buffer was empty. The SPORTs transmit data whenever they detect a
SPORTx_FS
signal. If cleared (=0), no
SPORTx_FS
signal occurred.
This bit applies to multichannel mode only when the SPORTs are
configured as transmitters.
Bits 31-30 (
TXS_A
) in the
SPCTL0
,
SPCTL2
,
SPCTL4
registers indicate the sta-
tus of the serial port channel’s transmit buffer as follows: 11= buffer full,
00=buffer empty, 10=buffer partially full. These bits apply to multichan-
nel mode only.
Channel Selection Registers
Specific channels can be individually enabled or disabled to select the
words that are received and transmitted during multichannel communica-
tions. Data words from the enabled channels are received or transmitted,
while disabled channel words are ignored. Up to 128 channels are avail-
able for transmitting and receiving.
The multichannel selection registers enable and disable individual chan-
nels. The registers for each serial port are shown in
.
Table 9-2. Multichannel Selection Registers
Register Names
Function
MR1CS(0–3)
MR3CS(0–3)
MR5CS(0–3)
Multichannel Receive Select s
pecifies the active receive channels
(4x32-bit registers for 128 channels).
MT0CS(0–3)
MT2CS(0–3)
MT4CS(0–3)
Multichannel Transmit Select
specifies the active transmit channels
(4x32-bit registers for 128 channels).
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 ...