ADSP-214xx SHARC Processor Hardware Reference
4-7
Link Ports—ADSP-2146x
5. Receiver accepts the remaining word even if
LACK
is deasserted. The
transmitter does not send the following word.
6. Transmit data for next word is held until
LACK
is asserted.
The receive buffer may fill if a higher priority DMA, core I/O processor
register access, or chain loading operation is occurring. The
LACKx
signal
may deassert when it anticipates the buffer may fill. The
LACKx
signal is
reasserted by the receiver as soon as the internal DMA grant signal has
occurred, freeing a buffer location or the core reads the receive buffer
RXLBx
thereby freeing a buffer location. The
LACKx
signal inhibits trans-
mission of next word and not of the current byte.
Data is latched in the receive buffer on the falling edge of
LCLKx
.
The receive operation is purely asynchronous and can occur at any
frequency up to 166 MHz or peripheral clock frequency (which-
ever is less).
When a link port is not enabled,
LDAT7-0
,
LCLKx
and
LACKx
are
three-stated. When a link port is enabled to transmit, the data pins are
driven with whatever data is in the output buffer,
LCLKx
is driven high and
LACKx
is three-stated. When a port is enabled to receive, the data pins and
LCLKx
are three-stated and
LACKx
is driven high.
Intercommunication
The transmitter and the receiver may be enabled at different times. The
LACKx
and
LCLKx
signals should be held low with the external pull-down
resistors. If the transmitter is enabled before the receiver, the
LACKx
signal
(of the receiver) is held low and transmission is held off. If the receiver is
enabled before the transmitter, the
LCLKx
signal (of the transmitter) is held
low by the pull-down and the receiver is held off.
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Содержание SHARC ADSP-214 Series
Страница 60: ...Contents lx ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...