ADAT transmit

The codebase supports a single ADAT transmitter that can transmit eight channels of uncompressed digital audio at sample-rates of 44.1 or 48 kHz over an optical cable. Higher rates are supported with a reduced number of samples via S/MUX (‘sample multiplexing’). Using S/MUX, the ADAT transmitter can transmit four channels at 88.2 or 96 kHz or two channels at 176.4 or 192 kHz.

In order to provide ADAT transmit functionality lib_xua uses lib_adat.

Basic configuration of ADAT transmit functionality is achieved with the defines in Table 19.

Table 19 ADAT transmit defines

Define	Description	Default
XUA_ADAT_TX_EN	Enable ADAT transmit	0 (Disabled)
ADAT_TX_INDEX	Start channel index of ADAT TX channels	N/A (must be defined by the application)
ADAT_TX_USE_SHARED_BUFF	Use shared memory when transferring samples between AudioHub and the ADAT tansmitter task	N/A (must be defined by the application)

The ADAT transmitter runs on the same tile as the Audio IO (AUDIO_IO_TILE)

The codebase expects the ADAT transmit port to be defined in the application XN file as PORT_ADAT_OUT. This must be a 1-bit port, for example:

<Port Location="XS1_PORT_1G"  Name="PORT_ADAT_OUT"/>