SLOS948 February 2019 TAS6424M-Q1
Right-justified (RJ) timing also uses the FSYNC pin to define when the data being transmitted is for the left channel and when the data is for the right channel. The FSYNC pin is high for the left channel and low for the right channel. A bit clock running at 32 × fS or 64 × fS is used to clock in the data. The first bit of data appears on the data 8-bit clock periods (for 24-bit data) after the FSYNC pin toggles. In RJ mode the LSB of data is always clocked by the last bit clock before the FSYNC pin transitions. The data is written MSB-first and is valid on the rising edge of bit clock. The device pads the unused leading data-bit positions in the L/R frame with zeros.