Intel® FPGA AI Suite: SoC Design Example User Guide

ID 768979
Date 9/06/2023
Public

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6.7. PLL Configuration

The Intel® FPGA AI Suite IP is designed to operate at high fMAX rates in Intel® FPGA devices. The SoC design example provides an IOPLL that provides the IP with a fast clock.

In the design example the external board 100 MHz reference clock is fed into the PLL and a 200 MHz output clock is produced. This clock feeds the Intel® FPGA AI Suite IP directly.

You can remove or alter this PLL if you want to profile different performance curves of the system.

The Intel® FPGA AI Suite dla_benchmark application has no runtime method to dynamically determine the PLL operating frequency in the SOC design. The frequency of 200 MHz has been set as a constant in this application source code. If you alter the PLL frequency, you must also alter the dla_benchmark application to match the new clock frequency. This matching ensures that the benchmark metrics accurately reflect the performance.

See dla_mmd_get_coredla_clock_freq in $COREDLA_WORK/runtime/coredla_device/mmd/hps_platform/acl_hps.cpp and change the return value accordingly.