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 |