SPORT Control Registers and Data Buffers
9-56
ADSP-2126x SHARC Processor Hardware Reference
Serial Port DMA Chaining Enable.
SPCTLx
bits 19 and 21 (
SCHEN_A
and
SCHEN_B
). These bits enable (if set, = 1) or disables (if cleared, = 0) serial
port’s channels A and B DMA chaining. Bits 19 and 21 apply to all oper-
ating modes.
Frame Sync Both Enable.
SPCTLx
bit 22 (
FS_BOTH
). This bit applies when
the SPORTS channels A and B are configured to transmit/receive data. If
set (= 1), this bit issues frame sync only when data is present in
both
trans-
mit buffers,
TXA
and
TXB
. If cleared (= 0), a frame sync is issued if data is
present in either transmit buffers. This bit applies to DSP Standard Serial
mode only.
When a SPORT is configured as a receiver, if
FS_BOTH
is set (= 1), frame
sync is issued only when both the Rx FIFOs (
RXSPA
and
RXSPB
) are not
full.
This bit is not used for I
2
S and Left-justified Sample Pair modes. If only
channel A or channel B is selected, the frame sync behaves as if
FS_BOTH
is
cleared (= 0). If both A and B channels are selected, the word select acts as
if
FS_BOTH
is set (= 1).
Buffer Hang Disable.
SPCTLx
bit 23 (BHD). When cleared (= 0), this bit
causes the processor core to hang when it attempts to write to a full buffer
or read from an empty buffer. When set (= 1), this bit disables the
core-hang. In this case, a core read from an empty receive buffer returns
previously-read (invalid) data and core writes to a full transmit buffer to
overwrite (valid) data that has not yet been transmitted. This bit is used in
all modes.
Data Direction Control
.
SPCTLx
bit 25 (
SPTRAN
). This bit controls the
data direction of the serial port channel A and B signals.
• 0 = SPORT is configured to receive on both channels A and B. In
this configuration, the
RXSPxA
and
RXSPxB
buffers are activated,
while the Receive Shift registers are controlled by
SPORTx_CLK
and
SPORTx_FS
. The
TXSPxA
and
TXSPxB
buffers are inactive.
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 ...