E-Tile Transceiver PHY User Guide

ID 683723
Date 4/01/2024
Document Table of Contents General PMA Tuning Guidelines

Observe these guidelines for custom data rate and channel situations. Data rates of 6.5 Gbps and below can use manual CTLE if a long initial adaption time is not acceptable.
  • Minimize your use of TX equalization.
    Table 45.  Recommended TX Attenuation Value (VOD)
    Insertion Loss < 10 dB > 10 dB
    TX equalization Attenuation Value (VOD)


    This is only useful for loopback tests; it does not apply for actual applications. For actual applications, tune the launch VOD of the link partner to get the optimal BER at the E-tile receiver.

  • Sweep the GS1 and GS2 parameters when possible.
    Table 46.  Typical GS1/GS2 SettingsFor lower data rates with higher insertion loss, you can use higher values.
    Insertion Loss < 13 dB > 13 dB
    GS1 0 1
    GS2 1 2
  • The typical values for RF_B0 and RF_B1 are 1 and 4. For high data rates (50 Gbps and above) and for longer channels (20 dB and above), you can use a RF_B1 value of 6 or 8 (maximum) to take advantage of full EQ capabilities. Depending on the system and temperature ramp, you may be required to use a RF_B0 setting of 2 to allow sufficient room on both up and down ramps.
  • Sweep the RF_B0/RF_B1 values and apply optimized values for a channel or group (short/medium/long) of channels whenever possible.
  • During continuous adaptation, fixing LF_Max (which limits the LF adaptation range) and adapting RF_B0 provides the best performance over temperature ramp.