Visible to Intel only — GUID: yqk1699440936572
Ixiasoft
Visible to Intel only — GUID: yqk1699440936572
Ixiasoft
7.1. TX MAC Interface to User Logic
Signal | Direction | Description |
---|---|---|
clk_txmac | Output | Clock for the TX logic. Derived from o_clk_tx_div and is an output from the F-Tile Low Latency 100G Ethernet Intel® FPGA IP core. clk_txmac is guaranteed to be stable when tx_lanes_stable is asserted. The frequency of this clock is 390.625 MHz. All TX MAC interface signals are synchronous to clk_txmac . |
l8_tx_data[511:0] | Input | Data input to MAC. Bit 511 is the MSB and bit 0 is the LSB. Bytes are read in the usual left to right order. The F-Tile Low Latency 100G Ethernet Intel® FPGA IP core does not process incoming frames of less than nine bytes correctly. You must ensure such frames do not reach the TX client interface. You must send each TX data packet without intermediate idle cycles. Therefore, you must ensure your application can provide the data for a single packet in consecutive clock cycles. If data might not be available otherwise, you must buffer the data in your design and wait to assert l8_tx_startofpacket when you are assured the packet data to send on l8_tx_data[511:0] is available or will be available on time. If readyLatency = 0, ensure that no data transition at the l8_tx_data bus at the same clock cycle l8_tx_ready is deasserted. You can transition the data at the l8_tx_data bus at the same clock cycle l8_tx_ready is asserted. If readyLatency = 3, ensure that no data transition at the l8_tx_data bus at the third clock cycle after l8_tx_ready is deasserted. You can transition the data at the l8_tx_data bus at the third clock cycles after l8_tx_ready is asserted. |
l8_tx_valid | Input | When asserted, indicates valid data is available on l8_tx_data[511:0]. You must assert this signal continuously between the assertions of l8_tx_startofpacket and l8_tx_endofpacket for the same packet regardless of the l8_tx_ready status. |
l8_tx_startofpacket | Input | When asserted, indicates the first byte of a frame. When l8_tx_startofpacket is asserted, the MSB of l8_tx_data drives the start of packet. Packets that drive l8_tx_startofpacket and l8_tx_endofpacket in the same cycle are ignored. |
l8_tx_endofpacket | Input | When asserted, indicates the end of a packet. Packets that drive l8_tx_startofpacket and l8_tx_endofpacket in the same cycle are ignored. |
l8_tx_empty[3:0] | Input | Specifies the number of empty bytes on l8_tx_data when l8_tx_endofpacket is asserted. |
l8_tx_error | Input | When asserted in the same cycle as l8_tx_endofpacket, indicates the current packet should be treated as an error packet. Assertion at any other position in the packet is ignored. The TX statistics counters do not reflect errors the IP core creates in response to this signal. |
l8_tx_ready | Output | When asserted, indicates that the MAC can accept the data. When the readyLatency = 0, the IP core accepts valid data in the same clock cycle in which it asserts l8_tx_ready. When the readyLatency = 3, the IP core accepts valid data 3 clock cycles after it asserts l8_tx_ready. |
l8_txstatus_valid | Output | When asserted, indicates that l8_txstatus_data[39:0] is driving valid data. |
l8_txstatus_data[39:0] | Output | Specifies information about the transmit frame. The following fields are defined:
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l8_txstatus_error[6:0] | Output | Specifies the error type in the transmit frame. The following fields are defined:
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