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

ID 683100
Date 2/16/2022
Public

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6.4.1. Disabling Background Calibration

For Intel® Stratix® 10 H-tile production devices, disable the background calibration first prior to accessing the transceiver core reconfiguration register. The Intel® Stratix® 10 H-tile ES devices and all variants of Intel® Stratix® 10 L-tile devices (ES and production) do not have background calibration.

In Intel® Quartus® Prime software version 19.2 onwards, use the following steps to access the transceiver core reconfiguration registers:

  1. Write 0x1 into register 0x325[12] of the Avalon® memory-mapped control and status interface to hold the auto adaptation module in an Idle state.
  2. Write 0x0 into register 0x542[0] with the channel offset address of the transceiver control and status registers using the transceiver reconfiguration Avalon® memory-mapped interface to disable background calibration. The background calibration must be disabled for all four lanes before accessing the transceiver control and status registers of any of four lanes.
  3. Access the transceiver register, for example, to perform the transceiver reconfiguration.
  4. Once completed, write 0x1 into register 0x542[0] with the channel offset address of the transceiver control and status registers using the transceiver reconfiguration Avalon® memory-mapped interface to enable background calibration. The background calibration must be enabled for all four lanes after accessing the transceiver control and status registers of any of four lanes.
  5. Write 0x0 into register 0x325[12] of the Avalon® memory-mapped control and status interface to release the auto adaptation module from the Idle state.