Intel® Cyclone® 10 GX Transceiver PHY User Guide

ID 683054
Date 4/14/2023
Document Table of Contents

7.5.4. PMA Recalibration

PMA calibration includes:

  • PMA TX calibration
  • PMA RX calibration

The PMA RX calibration includes CDR/CMU PLL calibration, offset cancellation calibration, and VCM calibration. The TX PMA calibration includes TX termination, Vod, and DCD calibration.

Follow these steps to recalibrate the PMA:

  1. Request access to the internal configuration bus by writing 0x2 to offset address 0x0[7:0].
  2. Wait for reconfig_waitrequest to be deasserted (logic low), or wait until capability register of PreSICE Avalon-MM interface control 0x281[2]=0x0.
  3. Configure the PMA calibration enable register 0x100.
    • Read-Modify-Write 0x1 to 0x100[1] to start PMA RX calibration.
    • Read-Modify-Write 0x1 to 0x100[5] to start PMA TX calibration.
    • Read-Modify-Write 0x0 to 0x100[6] to disable adaptation mode.
  4. If there is a data rate change in the CDR, set the rate switch flag register 0x166[7] for PMA RX calibration.
    • Read-Modify-Write 0x1 to offset address 0x166[7] if no rate switch.
    • Read-Modify-Write 0x0 to offset address 0x166[7] if switched rate with different CDR bandwidth setting.
    Note: Refer to Rate Switch Flag Registerfor more information.
  5. Do Read-Modify-Write the proper value to capability register 0x281[5:4] for PMA calibration to enable/disable tx_cal_busy or rx_cal_busy output.
    • To enable rx_cal_busy, Read-Modify-Write 0x1 to 0x281[5].
    • To disable rx_cal_busy, Read-Modify-Write 0x0 to 0x281[5].
    • To enable tx_cal_busy, Read-Modify-Write 0x1 to 0x281[4].
    • To disable tx_cal_busy, Read-Modify-Write 0x0 to 0x281[4].
    Note: Refer to PMA Capability Registers for Calibration Status for more information.
  6. Release the internal configuration bus to PreSICE to perform recalibration by writing 0x1 to offset address 0x0[7:0].
  7. Periodically check the *cal_busy output signals or read the capability registers 0x281[1:0] to check *cal_busy status until calibration is complete.