Agilex™ 7 F-Series and I-Series Known Issue List

ID 683584
Date 3/13/2025
Public
Document Table of Contents

2.1.2.14. No response received during read operation on the xcvr_reconfig interface after an FPGA re-configuration

Description

The xcvr_reconfig interface in the R-Tile Intel FPGA IP for PCIe requires to have write and read transactions issued in multiples of 8. Not meeting this guideline can cause a lack of response for read operation on the xcvr_reconfig interface after an FPGA re-configuration and it might require a FPGA power cycle in order to recover the access to the xcvr_reconfig interface.

Workaround

The FPGA Application logic must keep track of the number of write and read transactions performed on the xcvr_reconfig interface prior to the FPGA reconfiguration.

The following guideline describes the tracking that needs to be implemented to track the number of transactions prior the FPGA reconfiguration:

  1. The FPGA Application logic implements two separate transaction counters, one for read operations and one for write operations.
  2. The FPGA Application logic increases this counter for every transaction issued in the xcvr_reconfig interface.
  3. Once FPGA Application logic has completed the accesses required on the xcvr_reconfig interface, it must evaluate the counter and confirm it is a multiple of 8.
    • In case additional write operations are required, the FPGA Application logic must perform the additional write operations with a value of 0x0 to the address offset 0x6_0000.
    • In case additional read transactions are required, the FPGA Application logic must perform the additional read operations to the address offset 0x6_0000. For example, if FPGA Application logic performed only one write operation and two read operations on the xcvr_reconfig interface, as soon as those operations are completed, the FPGA Application logic must perform an additional seven dummy write operations and six dummy read operations to the register offset provided above. This ensures the numbers of transaction issued on the xcvr_reconfig interface is always a multiple of eight.

Status

Table 34.  Device Status Table
Devices Affected Planned Fix
  • AGIx019R18Axxxxx
  • AGIx023R18Axxxxx
  • AGIx022R29Axxxxx
  • AGIx027R29Axxxxx
  • AGIx022R31Axxxxx
  • AGIx027R31Axxxxx
  • AGIx041R29xxxxxx
  • AGIx041R31Exxxxx
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