Configuration via Protocol (CvP) Implementation User Guide: Agilex™ 5 FPGAs and SoCs

ID 813775
Date 10/02/2024
Public

4.1.1. FPGA Power Supplies Ramp Time Requirement

For an open system, you must ensure that your design adheres to the FPGA power supplies ramp-up time requirement.

The power-on reset (POR) circuitry keeps the FPGA in the reset state until the power supply outputs are in the recommended operating range. A POR event occurs from when you power up the FPGA until the power supplies reach the recommended operating range within the maximum power supply ramp time, tRAMP . If tRAMP is not met, the device I/O pins and programming registers remain tri-stated, during which device configuration can fail.

To meet the PCIe* link up time for CvP, the total tRAMP must be less than 10 ms, from the first power supply ramp-up to the last power supply ramp-up. You must select ASx4 fast mode for MSEL settings to make sure the shortest POR delay.

Figure 5. FPGA Power Supplies Ramp-Up Time and POR