SPORT Control Registers and Data Buffers
9-62
ADSP-2126x SHARC Processor Hardware Reference
interrupt is masked if serial port DMA is enabled or if the corresponding
bit in the
LIRPTL
register is set.
If your program causes the core processor to attempt to read from an
empty receive buffer or to write to a full transmit buffer, the access is
delayed until the buffer is accessed by the external I/O device. This delay
is called a core processor hang. If you do not know if the core processor
can access the receive or transmit buffer without a hang, the buffer’s status
should be read first (in
SPCTLx
) to determine if the access can be made.
To support debugging buffer transfers, the processor has a Buffer
Hang Disable (
BHD
) bit. When set (= 1), this bit prevents the pro-
cessor core from detecting a buffer-related stall condition,
permitting debugging of this type of stall condition. For more
information, see the
BHD
.
The status bits in
SPCTLx
are updated during reads and writes from the
core processor even when the serial port is disabled. Disable the serial port
when writing to the receive buffer or reading from the transmit buffer.
When programming the serial port channel (A or B) as a transmit-
ter, only the corresponding
TXSPxA
and
TXSPxB
buffers become
active while the receive buffers
RXSPxA
and
RXSPxB
remain inactive.
Similarly, when the SPORT channel A and B are programmed as
receive-only the corresponding
RXSPxA
and
RXSPxB
is activated. Do
not attempt to read or write to inactive data buffers. If the proces-
sor operates on the inactive transmit or receive buffers while the
SPORT is enabled, unpredictable results may occur.
Clock and Frame Sync Frequencies (DIV)
The
DIVx
registers contain divisor values that determine frequencies for
internally-generated clocks and frame syncs. The
DIVx
registers are
described in Appendix A in
“SPORT Divisor Registers (DIVx)” on
.
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 ...