Timing Analysis for PCI Express Compiler × Variations That Target a Cyclone IV GX Device

Description

The Quartus II software does not perform timing analysis for the FPGA fabric in Cyclone IV GX × variants; consequently, variants that would fail timing analysis are not identified.

This issue affects × variants in the Cyclone IV GX device.

Resolution

You can manually create the required clock constraint. provides the equation for this constraint. In this equation <n> is 8.000 for a 125 MHz application clock and 16 for a 62.5 MHz application clock.

Clock Constraint

# create_clock -name {core_clk_out} -period <n> -waveform { 0.000 8.000 } [get_nets {*altpcie_hip_pipen1b_inst | core_clk_out~clkctrl}]

This issue is fixed in version 10.1 of the Quartus II software.