L- and H-Tile Transceiver PHY User Guide

ID 683621
Date 1/30/2024
Document Table of Contents

A.2.1. CDR/CMU and PMA Calibration

Enables user to optimize CDR/CMU and PMA performance when changing the data rate, reference clock, or both.
Name Address Type Attribute Name Encodings
Internal configuration bus arbitration register


read-write pcs_arbiter_ctrl

This bit arbitrates the control of internal configuration bus

Write 1'b0 to control the internal configuration bus by user.

Write 1'b1 to pass the internal configuration bus control to PreSICE.

PMA Calibration Status


read-write pcs_cal_done

Status for calibration done or not done. This is an OR operation, and if both TX and RX calibration are enabled, PreSICE calibrates RX first, then TX. After both have completed, the calibration is complete.

This is inverted cal_busy signal.

1'b1: calibration done

1'b0: calibration not done

PMA RX calibration enable


read-write pm_cr2_tx_rx_uc_rx_cal

PMA RX calibration enable

1'b1: RX calibration enable on

1'b0: RX calibration enable off

PMA TX calibration enable


read-write uc_tx_cal

PMA TX calibration enable

1'b1: TX calibration enable on

1'b0: TX calibration enable off

Request PreSICE to configure the CDR/CMU PLL in preparation for reconfiguration


read-write pre_reconfig

Rate switch flag register when you use the PMA as a RX channel. The power up default value is 0x0.

0x0: PreSICE uses the default CDR charge pump bandwidth from the default memory space.

0x1: PreSICE uses the CDR charge pump bandwidth setting from the Avalon® memory-mapped interface space register space.

Request PreSICE to configure the PLL in preparation for reconfiguration when the PMA is configured as a CMU PLL:

1'b1: Request PreSICE to configure the PLL in reconfiguration mode

1'b0: Reconfiguration mode not requested

Background calibration 0x542[0] read-write enable_background_cal

Request background calibration when the feature is enabled in the Native PHY IP core:

  • 1'b1: Enabled Background Calibration
  • 1'b0: Disable Background Calibration