The procedure for transmitting a two-cycle UFC message is
shown in the following figure. In this case the user application is sending a 4-byte
message using a 2-byte interface. s_axi_tx_tready is deasserted for
three cycles: one cycle for the UFC header which is sent during the
s_axi_ufc_tx_tready cycle, and two cycles for UFC data.
Figure 1. Transmitting a Multicycle UFC Message
