Forum Discussion

TPerm1's avatar
TPerm1
Icon for New Contributor rankNew Contributor
6 years ago

Cyclone V nCEO pin

Hi,

We are using the nCEO pins in order to perform multi-device configuration. We have pulled nCEO up to VCCPGM with a 10K resistor as recommended by the document "Cyclone® V Device Family Pin Connection Guidelines".

We are using device 5CEBA2F17C8N. nCEO is in bank 5A, with VCCIO5A connected to 1.8V. We have pulled nCEO to VCCPGM, which is connected to 3.3V. Will this cause issues since nCEO pin is pulled to a voltage above VCCIO?

Thanks,

Tom

1 Reply

  • AnandRaj_S_Intel's avatar
    AnandRaj_S_Intel
    Icon for Regular Contributor rankRegular Contributor
    6 years ago

    Hi Tom,

    We have to Connect the resistor to a supply that provides an acceptable input signal for the FPGA device.

    VCCPGM must be high enough to meet the VIH specification of the I/O on the device and the external host.

    Most important point is that the operating voltage(VCCPGM ) for the configuration input pin is independent of the I/O banks power supply, VCCIO, during configuration. Therefore, Cyclone V devices do not require configuration voltage constraints on VCCIO.

    Let me know if this has helped resolve the issue you are facing or if you need any further assistance.

    Regards

    Anand