Analog Devices ADSP-21261 SHARC Hardware Reference Manual page 535

Digital Audio Interface
( ). Note that the input and output signal pair are never
SPORTx_CLK_PE_O
used simultaneously. The pin enable signal dictates which of the two
SPORT lines appears at the DAI pin at any given time. By connecting all
three signals through the SRU, the standard SPORT configuration regis-
ters behave as documented in "Serial Ports" in Chapter 9, Serial Ports.
The SRU then becomes transparent to the peripheral. Figure 12-10
demonstrates SPORT0 properly routed to DAI pins one through four;
although it can be equally well routed to any of the 20 DAI pins.
Though SPORT signals are capable of operating in this bidirectional man-
ner, it is not required that they be connected to the pin buffer this way. As
mentioned above, if the system design only uses a SPORT signal in one
direction, it is simpler and safer to connect the pin buffer enable pin
directly high or low as appropriate. Furthermore, signals in the SRU other
than the pin buffer enable signal (which is generated by the peripheral)
may be routed to the pin buffer enable input. For example, an outside
source may be used to 'gate' a pin buffer output by controlling the corre-
sponding pin buffer enable.
ADSP-2126x SHARC Processor Hardware Reference 12-13