ADSP-2126x SHARC Processor Hardware Reference
9-39
Serial Ports
When
DIFS
= 1 and
SPTRAN
= 1, the internally-generated transmit frame
sync is output at its programmed interval regardless of whether new data is
available in the transmit buffer. The processor generates the transmit
SPORTx_FS
signal at the frequency specified by the value loaded in the
DIV
register. If a frame sync occurs when the transmitter FIFO is empty, the
MSB or LSB (depending on how the
LSBF
bit in
SPCTL
is set) of the previ-
ous word is transmitted. When
DIFS
= 1 and
SPTRAN
= 0, a receive
SPORTx_FS
signal is generated regardless of the receive data buffer status.
Depending on the SPORT operating mode, the Transmitter Underflow
(
TUVF_A
or
TUVF_B
) bit is set if the transmit buffer does not have new data
when a frame sync occurs; or a Receive Overflow bit (
ROVF_A
or
ROVF_B
) is
set if the receive buffers are full and a new data word is received.
If the internally-generated frame sync is used and
DIFS
=0, a single write to
the transmit data register is required to start the transfer.
Data Word Formats
The format of the data words transmitted over the serial ports is config-
ured by the
DTYPE
,
LSBF
,
SLEN
, and
PACK
bits of the
SPCTLx
control
registers.
Word Length
Serial ports can process word lengths of 3 to 32 bits for Serial and Multi-
channel modes and 8 to 32 bits for I
2
S mode. Word length is configured
using the 5-bit
SLEN
field in the
SPCTLx
Control registers. Refer to
The value of
SLEN
is:
SLEN
= serial word length – 1
Содержание ADSP-21261 SHARC
Страница 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Страница 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Страница 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Страница 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Страница 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Страница 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...