The UFC interface is created when the core is
generated with UFC enabled (see the following figure). UFC
s_axi_ufc_tx_tvalid and s_axi_ufc_tx_tready ports on the
TX side start the UFC message and a 3-bit s_axi_ufc_tx_tdata port specifies
the length of the message. With s_axi_ufc_tx_tready asserted, the UFC
message can be supplied to the data port.
Figure 1. Aurora 8B/10B Core UFC Interface
The RX side of the UFC interface consists of a set of AXI4-Stream ports that allows the UFC message to be read as a frame. Simplex modules retain only the interface needed to send data in the supported direction.
The following table describes the ports for the UFC interface.
| Name | Direction | Clock Domain | Description |
|---|---|---|---|
| UFC_S_AXIS_TX | |||
| s_axi_ufc_tx_tvalid | Input | user_clk | Asserted to request a UFC message be sent to the channel partner. Must be held until s_axi_ufc_tx_tready is asserted. Do not assert this signal unless the entire UFC message is ready to be sent; a UFC message cannot be interrupted after it has started. |
| s_axi_ufc_tx_tdata[0:2] or s_axi_ufc_tx_tdata[2:0] | Input | user_clk | Specifies the size of the UFC message that is sent. The SIZE encoding is a value between 0 and 7. See the following table. |
| s_axi_ufc_tx_tready | Output | user_clk | Asserted when an Aurora 8B/10B core is ready to read the contents of the UFC message. On the cycle after the s_axi_ufc_tx_tready signal is asserted, data on the s_axi_tx_tdata port is treated as UFC data. s_axi_tx_tdata data continues to be used to fill the UFC message until enough cycles have passed to send the complete message. Unused bytes from a UFC cycle are discarded. |
| UFC_M_AXIS_RX | |||
| m_axi_ufc_rx_tdata[0:(8n–1)] or m_axi_ufc_rx_tdata[(8n–1):0] | Output | user_clk | Incoming UFC message data from the channel partner (n = 16 bytes maximum). |
| m_axi_ufc_rx_tvalid | Output | user_clk | Asserted when the values on the m_axi_ufc_rx_tdata ports are valid. |
| m_axi_ufc_rx_tlast | Output | user_clk | Signals the end of the incoming UFC message. |
| m_axi_ufc_rx_tkeep[0:(n–1)] or m_axi_ufc_rx_tkeep[(n–1):0] | Output | user_clk | Specifies the number of valid bytes of data presented on the m_axi_ufc_rx_tdata port on the last word of a UFC message. Valid only when m_axi_ufc_rx_tlast is asserted (n = 16 bytes maximum). |