3.2.3. Coefficient and Equalization Limit Test

Filename

xena_lt_coeff_eq_limit.py

Objective

To make the test port to respond COEFF_EQ_AT_LIMIT or COEFF_AT_LIMIT or EQ_AT_LIMIT when keep incrementing a coefficient on the remote transmitter.

Configurations

• Number of <repetitions>, default to 1

• AN/LT Configuration

  • AN enabled/disabled.

  • <preset> the remote transmitter should start.

  • <coefficients> of the remote transmitter.

  • LT control action: INCREMENT

  • <serdes> the serdes lane(s) to test

• Port configuration

  • Interface type, e.g. QSFPDD 100G CR

  • Serdes speed

  • Number of Serdes (read-only)

Procedure

1. If AN is enabled, test port starts AN + interactive LT. Else, start interactive LT on the port.

2. AN Phase

   • 2.1. If AN result is AN_GOOD_CHECK, continue to LT Phase.

   • 2.2. If AN result is not AN_GOOD_CHECK, quit the test and report AN failure with the AN status.

3. LT Phase:

   • 3.1. Request the remote transmitter to use PAM4 or PAM with Precoding modulation.

   • 3.2. Request the remote transmitter to use <preset> on each specified Serdes.

   • 3.3. Request the remote transmitter to INCREMENT coefficient on each specified Serdes.

   • 3.4. If the response is COEFF_EQ_AT_LIMIT or COEFF_AT_LIMIT or EQ_AT_LIMIT or COEFF_NOT_SUPPORTED, then test is OK.

   • 3.5. If frame lock is lost, then the test is failed.

   • 3.6. Report the response on each specified Serdes.

4. Stop AN and LT on the test port.

5. Repeat 1-4 until all <coefficients> are tested.

6. Repeat 1-5 until all <repetitions> are tested.

Note

This test may cause the local port to lose frame lock to the remote port.

Statistics

• Timestamp

• Repetition #

• AN status

• For each Serdes

  • Starting preset

  • For each coefficient

    • Last response