AN 871: Quick Guide for Intel® Arria® 10 and Intel® Cyclone® 10 GX Transceiver High-Speed Link Tuning

ID 683449
Date 9/26/2018
Public

1.3. Optimizing Your Settings

  1. When the BER is acceptable, use the Auto Sweep feature on the Advanced tab of the Transceiver Toolkit to sweep the values in the Transceiver Toolkit to determine the settings that meet the BER 10-12 condition.
    Table 3.  Acceptable BER Example Values
    Datarate Acceptable BER4 Auto Sweep Range5 Range Guide
    TX VOD 31 31 If the maximum VOD is used, do not sweep the VOD. Otherwise, sweep ± 5 of the values.
    Pre-emphasis First Post-Tap -8 0 to -18 If negative, only sweep across negative values. If positive, only sweep across positive values. Sweep ± 10 of the values.
    Pre-emphasis First Pre-Tap -3 -3 to -12 (maximum) If negative, only sweep across negative values. If positive, only sweep across positive values. Sweep all positive or negative values.
    Equalizer Stage Single Single Fixed
    CTLE AC Gain 15 5 to 25 Sweep ± 10 of the values.
    CTLE DC Gain 1 1 If DC gain setting 0 is used for acceptable BER, do not sweep. Else, sweep DC gain settings 1 - 4..
    VGA 2 1 to 4 If the VGA setting for acceptable BER is > 0, sweep across VGA settings 1 - 4.
    DFE Adaptation Enabled Enabled  
  2. Select the middle value for the settings range that PASS for the BER 10-12 condition. The middle value is the optimized value.
    Table 4.  BER 10-12 Condition PASS Settings ExampleThe green boxes indicate settings that pass, and the red boxes indicate settings that fail.
    CTLE AC gain settings 5 6 7 8 9 10 11 12 13 14 15 16 17
    BER BER 0 0 0 0 0 0 0 0 BER BER BER
    VGA 1 2 3 4                  
    BER 0 0 0                  
    DFE Adaptation 5 6 7 8 9 10 11 12 13 14 15 16 17
    BER BER BER BER 0 0 0 0 0 BER BER BER BER

    In this example, the following settings can be selected as optimum values:

    • CTLE AC gain = 10 or 11
    • VGA = 3
    • TX Pre-emphasis Post-Tap 1 = -11 (Make sure your Post-Tap setting is a negative value.)
  3. Using the Transceiver Toolkit, test the optimized BER 10-12 PASS settings across more channels, boards, or both. If you are unable to, repeat Step 2 to determine the overlapping range across more channels and the board.
4 Example settings after there has been an acceptable BER for 5 seconds
5 Range of values derived from the Auto Sweep feature on the Advanced tab of the Transceiver Toolkit that meet the BER 10-12 condition