V-Series Transceiver PHY IP Core User Guide

ID 683171
Date 7/26/2022
Public
Document Table of Contents

10.4.1. Data Interfaces

This topic describes the Avalon-ST TX and RX interface signals as well as the serial interface and status signals.
Table 133.  Avalon-ST TX Interface Signals
Signal Name Direction Description
tx_parallel_data[(<n>43:0] Input This is TX parallel data driven from the MAC. The ready latency on this interface is 0, so that the PHY must be able to accept data as soon as it comes out of reset.

The bits of each 11-bit word have the following definitions when you enable 8B/10B encoding:

  • tx_parallel_data[7:0]: TX data bus.
  • tx_parallel_data[8]: TX data control character.
  • tx_parallel_data[9]: Force disparity. For the Gen1 and Gen2 PCIe PIPE interface, this signal forces running disparity to negative in compliance mode.
  • tx_parallel_data[10]: Disparity field.
    • 1'b0: Transmit positive disparity.
    • 1'b1: Transmit negative disparity.
    • For Gen1 and Gen2 PCIe PIPE - Forces the TX ouptu to electrical idle.

If 8B/10B encoding is disabled, the width of this interface is width you specified for FPGA fabric transceiver interface width If 8B/10B encoding is disabled, when you have enabled dynamic reconfiguration, the following mapping applies to each word:

  • tx_parallel_data[7:0]: Data input bus.
  • tx_parallel_data[10:8]: Unused.

Refer to Table 134 for the location of valid data for a single- and double-word data buses, with and without the byte serializer.

tx_clkout Output This is the clock for TX parallel data, control, and status signals.
tx_datak [< n >(<w>/<s>)-1:0] Input Data and control indicator for the transmitted data. When 0, indicates that tx_data is data, when 1, indicates that tx_data is control.
tx_forcedisp [< n >(<w>/<s>)-1:0] Input When asserted, this control signal enables disparity to be forced on the TX channel. This signal is created if you turn On the Enable manual disparity control option on the 8B/10B tab.
tx_dispval [< n >(<w>/<s>)-1:0] Input This control signal specifies the disparity of the data. When 0, indicates positive disparity, when 1, indicates negative disparity. This port is created if you turn On the Enable disparity control option on the 8B/10B tab.
Table 134.  Location of Valid Data Words for tx_parallel_data for Various FPGA Fabric to PCS Parameterizations The following table shows the valid 11-bit data words with and without the byte deserializer for single- and double-word FPGA fabric to PCS interface widths. The byte serializer allows the PCS to operate at twice the data width of the PMA . This feature allows the PCS to run at a lower frequency and accommodates a wider range of FPGA interface widths.
Configuration Bus Used Bits
Single word data bus, byte deserializer disabled [10:0] (word 0)
Single word data bus, byte serializer enabled [32:22], [10:0] (words 0 and 2)
Double word data bus, byte serializer disabled [21:0] (words 0 and 1)
Double word data bus, byte serializer enabled [43:0] (words 0-3)
Table 135.  Avalon-ST RX Interface SignalsThese signals are driven from the PCS to the MAC. This is an Avalon source interface.
Signal Name Direction Description
rx_parallel_data[<n>63:0] Output This is RX parallel data driven from the Custom PHY IP Core. The ready latency on this interface is 0, so that the MAC must be able to accept data as soon as the PHY comes out of reset. Data driven from this interface is always valid.

The bits of each 16-bit word have the following definitions when you enable 8B/10B decoding:

  • rx_parallel_data[7:0]: RX data bus
  • rx_parallel_data[8]: RX data control character
  • rx_parallel_data[9]: Code violation
  • rx_parallel_data[10]: Word alignment status
  • rx_parallel_data[11]: Disparity error
  • rx_parallel_data[12]: Pattern detect
  • rx_parallel_data[14:13]
    • 2'b00: Normal data
    • 2'b01: Deletion
    • 2'b10: Insertion (or Underflow with 9'h1FE or 9'h1F7
    • 2'b11: Overflow
  • rx_parallel_data[14:13]: Running disparity value

If 8B/10B decoding is disabled, the width of this interface is width you specified for FPGA fabric transceiver interface width. If 8B/10B encoding is disabled, when you have enabled dynamic reconfiguration, the following mapping applies to each word:

  • rx_parallel_data[9:0]: RX data bus
  • rx_parallel_data[10]: Sync status
  • rx_parallel_data[11]: Disparity error
  • rx_parallel_data[12]: Pattern detect
  • rx_parallel_data[14:13]
    • 2'b00: Normal data
    • 2'b01: Deletion
    • 2'b10: Insertion (or Underflow with 9'h1FE or 9'h1F7
    • 2'b11: Overflow
  • rx_parallel_data[15]: Running disparity value

Refer to Table 136 for the location of valid data for a single- and double-word data buses, with and without the byte serializer.

rx_clkout [< n >-1:0] Output This is the clock for the RX parallel data source interface.
rx_datak [< n >(<w>/<s>)-1:0] Output Data and control indicator for the source data. When 0, indicates that rx_parallel_data is data, when 1, indicates that rx_parallel_data is control.
rx_runningdisp [< n >(<w>/<s>)-1:0] Output This status signal indicates the disparity of the incoming data.
rx_enabyteord[< n >-1:0] Input This signal is created if you turn On the Enable byte ordering block control option on the Byte Order tab. A byte ordering operation occurs whenever rx_enabyteord is asserted. To perform multiple byte ordering operations, deassert and reassert rx_enabyteord.
Table 136.  Location of Valid Data Words for rx_parallel_data for Various FPGA Fabric to PCS Parameterizations The following table shows the valid 11-bit data words with and without the byte deserializer for single- and double-word FPGA fabric to PCS interface widths. The byte deserializer allows the PCS to operate at twice the data width of the PMA . This feature allows the PCS to run at a lower frequency and accommodates a wider range of FPGA interface widths.
Configuration Location of rx_parallel_data
Single word data bus, byte deserializer disabled [15:0] (word 0)
Single word data bus, byte serializer enabled [47:32], [15:0] (words 0 and 2)
Double word data bus, byte serializer disabled [31:0] (words 0 and 1)
Double word data bus, byte serializer enabled [63:0] (words 0-3)
Table 137.  Serial Interface and Status Signals
Signal Name Direction Signal Name
rx_serial_data[< n >-1:0] Input Receiver differential serial input data.
tx_serial_data[< n >-1:0] Output Transmitter differential serial output data.