Article ID: 000091403 Content Type: Troubleshooting Last Reviewed: 08/15/2023

Why does the O-RAN Intel® FPGA IP give incorrect values when Block floating-point compression is turned on?

Environment

  • Intel® Quartus® Prime Pro Edition
  • BUILT IN - ARTICLE INTRO SECOND COMPONENT
    Description

    Due to a problem in the O-RAN Intel® FPGA IP version 1.6.0 and earlier, you may see the O-RAN Intel FPGA IP gives incorrect values when Block floating-point compression is turned on.

    When the original PRB value is almost saturated at maximum positive value, O-RAN intel FPGA IP may generate a negative value of compressed PRB.

     

    For example, the original PRB value “8180” is compressed to 9 bits using the exponent value `5` and the compressed PRB value is incorrectly generated as 256 (0x100). The compressed value is expected to be decompressed as 16-bits and the expected value is 8192 (0x2000). However,  the decompressed outcome becomes 8192(0xE000).

     

    This problem impacts the IqWidth from `8` to `15`.

    The Fronthaul Compression Intel® FPGA IP has the same problem.

    Resolution

    This problem is fixed starting with the O-RAN Intel® FPGA IP and the Fronthaul Compression Intel FPGA IP webcore version 22.2.

    Related Products

    This article applies to 3 products

    Intel® Arria® 10 FPGAs and SoC FPGAs
    Intel® Stratix® 10 FPGAs and SoC FPGAs
    Intel Agilex® 7 FPGAs and SoC FPGAs