Answers Database


FPGA Configuration: XC4000E won't configure in socket designed for XC4000?


Record #760

Product Family: Hardware

Product Line: 4000E

Product Part: 4000E

Problem Title:
FPGA Configuration: XC4000E won't configure in socket designed for XC4000?


Problem Description:
Urgency: Standard

General Description:
In rare cases, you may find that an equivalent XC4000E device
does not configure when dropped into your existing XC4000 socket.


Solution 1:

You may encounter this problem if your design:

    1. Configures in peripheral, master parallel,
       or master serial mode
    2. Uses one or more mode pins as signal pins, AND
    3. Has pull-down resistors over 5k on one or more mode pins.

Note that all three of these criteria have to be met for
this problem to occur.

Change the high-resistance pulldowns to resistors of 5k or below.




End of Record #760 - Last Modified: 07/13/98 16:15

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