This Answer Record contains guidelines for upward pin-out migration in Spartan-3E packages.
Spartan-3E has introduced a new pin type called "input only." These pins are denoted as "IP" in the pin name (e.g., IP_Lxxy_#). It is important to take these pins into consideration when migrating to larger densities within a package.
The following pins go from being IO to IP in a larger device and should be used as inputs only if an upward migration is possible:
TQ144 P10 & P29 from '100E to '250E
FT256 D16 from '250E to '500E
FT256 F5, M14, & N2 from '500E to '1200E
FG320 E17, F4, P15, R4 from '500E to '1200E
FG320 A12 from '1200E to '1600E
For more information on footprint migration differences, see the Spartan-3E Pinout Description section in the Spartan-3E Data Sheet located at: