Low Latency 100G Ethernet Intel® FPGA IP Core User Guide: For Intel® Stratix® 10 Devices

ID 683100
Date 2/16/2022
Document Table of Contents

4.7. Auto Adaptation

The auto adaptation controls the RX PMA adaptation in the Transceiver PHY IP.

The auto adaptation, controlled by the auto adaptation module, continuously polls rx_is_lockedtodata signal. Asserting the rx_is_lockedtodata signal low triggers the auto adaptation module state machine. The auto adaptation state machine waits for the rx_is_lockedtodata signal to assert high. Once asserted and stable, the auto adaptation starts the RX PMA adaptation by accessing register 0x14c. For more information on RX PMA adaptation and specific register, refer to the L- and H-Tile Transceiver PHY User Guide.

In the H-tile production devices, the auto adaptation and background calibration shares the access to the transceiver reconfiguration interface. When the auto adaptation wants to gain the access to the transceiver reconfiguration interface, it disables the background calibration access (to the same transceiver reconfiguration interface).

In the H-tile ES devices, the background calibration is not supported. The auto adaptation module can directly access the transceiver reconfiguration interface.
Note: If a transceiver toolkit wants to gain access to the transceiver reconfiguration interface, you must hold the auto adaptation state machine in idle state by programming 0x325[12] bit. For steps on disabling the background calibration, refer to the Disabling Background Calibration.