This Figure shows an example of the signals on the TX user interface when an NFC message is received. In this case, the NFC message has a code of 0001, requesting two data beats of idles. The core deasserts s_axi_tx_tready on the user interface until enough idles have been sent to satisfy the request. In this example, the core is operating in immediate NFC mode, where NFC idles are inserted immediately. Aurora 8B/10B cores can also operate in completion mode, where NFC idles are only inserted between frames. If a completion mode core receives an NFC message while it is transmitting a frame, it finishes transmitting the frame before deasserting s_axi_tx_tready to insert idles.
