Agilex™ 7 Device Configuration via Protocol (CvP) Implementation User Guide

ID 683763
Date 4/01/2024
Document Table of Contents

1.3.1. CvP Limitations

The Agilex™ 7 device CvP implementation has the following limitations and restrictions in the current version of the Quartus® Prime software:
  • Any MemWR transaction is treated as CvP data before the device enters user mode. ConfigWR transactions are also supported.
  • When you poll the CVP_CREDIT bits from the CvP credit register, you must write the next 4 KB of fabric configuration data to the CvP data register within 50 ms of receiving an additional credit. Failure to send the data results in configuration failure.
  • The CvP response time is variable and depends on different conditions. The typical delay time is 5 sec and it is safe to wait till 1 min. So the driver should poll status in credit register to decide on driver timeout.
  • In CvP initialization and update mode, when FPGA fabric is not programmed, the PCIe* features that uses FPGA fabric are not accessible.
  • To generate the update image in the CvP update mode, you must use the same version of the Quartus® Prime software that you use to generate the base image.
  • If you use a .sof file to configure the FPGA with JTAG interface, the version of the Quartus® Prime that you used to generate the update bitstream must be the same as the version of the Quartus® Prime Programmer to program the FPGA.
  • For Agilex™ 7 designs that include the Hard Processor System (HPS), it is important to note that performing an FPGA core image update also causes the HPS to be reconfigured. The updated bitstream contains both the FPGA core data as well as the First Stage Bootloader (FSBL) used by the HPS.