9-8
ADSP-2126x SHARC Processor Hardware Reference
SPORTx_DB
signal, synchronous to the
SPORTx_CLK
receive clock. If framing
signals are used, the
SPORTx_FS
signal indicates the beginning of the serial
word being received. When an entire word is shifted in on the primary A
channel, the data is (optionally) expanded (SPORT1, 3, and 5 only), then
automatically transferred to the
RXSPxA
buffer. When an entire word is
shifted in on the secondary channel, it is automatically transferred to the
RXSPxB
buffer.
When the SPORT is configured as a receiver (
SPTRAN = 0
), the
RXSPxA
and
RXSPxB
buffers are activated along with the corresponding A and B chan-
nel receive shift registers, responding to
SPORTx_CLK
and
SPORTx_FS
for
reception of data. The transmit
TXSPxA
and
TXSPxB
buffer registers and
transmit A and B shift registers are inactive and do not respond to the
SPORTx_CLK
and
SPORTx_FS
. Since the
TXSPxA
and
TXSPxB
buffers are inac-
tive, writing to a transmit data buffer causes the core to hang indefinitely.
If the SPORTs are configured as receivers (
SPTRAN
bit = 0 in
SPCTLx
), programs should not write to the inactive
TXSPxA
and
TXSPxB
buffers. If the core keeps writing to the inactive buffer, the
transmit buffer status becomes full. This causes the core to hang
indefinitely since data is never transmitted out of the deactivated
transmit data buffers.
The processor SPORTs are not UARTs and cannot communicate with an
RS-232 device or any other asynchronous communications protocol. One
way to implement RS-232 compatible communication with the processor
is to use two of the
FLG
pins as asynchronous data receive and transmit sig-
nals. Examples of this can be found in the following documents.
• “Software UART”, in
Digital Signal Processing Applications Using
The ADSP-2100 Family
, Volume 2.
• Engineer-to-Engineer Note (EE-191),
Implementing a Glueless
UART Using the SHARC DSP SPORTs
.
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 ...