Visible to Intel only — GUID: mca1652928250541
Ixiasoft
Visible to Intel only — GUID: mca1652928250541
Ixiasoft
6.10.2. Calculating Deterministic Latency
Item | Value | Description |
---|---|---|
sampling_clk_period | 4.375ns (10M/100M/1G/2.5G) |
Period for sampling clock of 228.571 MHz for 1G/2.5G. |
UI period |
|
Unit interval. Indicates bit time of one serial bit for specific speed. For 2.5G, the line rate is 3.125Gbps and hence UI = 0.32ns (=1/3.125G). For 1G/10M/100M, the line rate is 1.25G. UI are calculated accordingly. |
parallel_clk | 20 UI | Period for 1 parallel clock cycle. |
tx_delay (TxDL) | Read from EFIFO-DL register [0x19:0x18] – [20:0] |
TX delay value in sampling_clk cycles, fixed point format Q13.8. Bit [20:8] is integer, bit [7:0] is fractional. Example: tx_delay = 0x27F4, Bit [20:8] = 0x27 = 39, Bit [7:0] = 0xF4 = 244/2^8 = 0.953125, Hence, tx_delay = 39.953125 clock cycles. |
rx_delay (RxDL) | Read from EFIFO-DL register [0x1B:0x1A] – [20:0] |
RX delay value in sampling_clk cycles, fixed point format Q13.8. Bit [20:8] is integer, bit [7:0] is fractional. |
TX PMA Delay |
|
TX PMA delay in the number of UI. Multiply by UI period to convert to nanoseconds and fractional nanoseconds format. |
RX PMA Delay |
|
RX PMA delay in the number of UI. Multiply by UI period to convert to nanoseconds and fractional nanoseconds format. |
TX Latency = TxDL * (sampling_clock_period in ns)
RX Latency = RxDL * (sampling_clock_period in ns)