AR# 173: XC4000/A: XC4000 and XC4000A bitstreams are NOT compatible!
XC4000/A: XC4000 and XC4000A bitstreams are NOT compatible!
Keywords: 4000A, 4000, bitstream, configuration
The bitstreams for XC4000 and XC4000A parts are not compatible. The 4k data book (Aug. '92) incorrectly lists the 4003/4003A and 4005/4005A parts as having the same frame and data sizes on p.26. The A parts have 4 bits fewer per frame, which is consistent with the reduced amount of interconnect in these parts.