Answers Database

XC4000E does not configure in socket designed for XC4000: possible workaround


Record #760

Product Family:  Hardware

Product Line:  4000E

Problem Title:
XC4000E does not configure in socket designed for XC4000: possible
workaround



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


Solution 1:

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



End of Record #760