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eharalanova's avatar
eharalanova
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17 days ago

Agilex 5E - PCIE PERST# pin - failing compilation

Hello! I'm using Critical Link MytiSom Dev Kit. It has the same FPGA as the Altera Dev Kit - A5ED065BB32AE6SR0. I'm adapting the PCIe Root Port example from Altera - I have assigned the PCIe Gen3x4 lanes to bank 4B. I have checked the pin assignments several times but I keep getting failed compilation with the error attached bellow. Any suggestions on what can cause the issue. I have also attached the pin assignments.

Thank you

3 Replies

  • eharalanova's avatar
    eharalanova
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    Thank you both for your reply. 

    I have carefully placed the PCIe RX/TX pins and used the corresponding p0_pin_perst_n_i and p0_pin_perst_n_i_1, but I might have made wrong connections in the QSYS. I have copied the Altera PCIe_subsys, it is then connected to pcie_clk_rst_subsys, pcie_gts_rst (for the system PLLs on the side of the PCIe), the 100 MHz clk reset, the 250 MHz clk reset which are synchronized in the top_wrapper.sv in the example design and are now synced on my top. Are all these needed? The wrapper contains also rst_ctrl. It seems to me that this is the place were something might get tangled because I have not connected the perst_n pins to anything else, but the corresponding inputs in the pcie_subsys 

  • Hi,

    The error message points to your pcie_perst_n.

     

    Please make sure you don't use this pin for other purpose in your design. Then confirm the pin location and voltage in your qsf. Below are the settings from Agilex5 Modular Dev Kit FYR. 

    set_instance_assignment -name IO_STANDARD "3.3V LVCMOS" -to p0_pin_perst_n_i_reset_n
    set_instance_assignment -name WEAK_PULL_DOWN ON -to p0_pin_perst_n_i_reset_n

     

     

    Regards,

    Rong

  • Hi eharalanova​,

    I would suggestion you to,

    Check the Critical Link MitySom Dev Kit board schematic for the the Pin and IO 
    Make sure have the pin assign in the correct bank and correct voltage.
    Ex. Altera Agilex 5 Premium Devkit  using 3.3v for PERST.

    Try to refer to the Critical Link guide on PCIe example design 

    https://support.criticallink.com/redmine/projects/mitysom_a5/wiki/Mitysom-a5e-pcie-gen3x4-ep

    If you have more details share here with us.