We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 356

MAKEBITS 5.0:XC3000A/L,3100A: Input does not appear to be connected internally


In XC3000A, XC3000L, and XC3100A devices, there is a bitstream generation
problem that may cause IOBs configured as inputs to not be
connected internally. The problem occurs when a design uses
one of the following pins:

---- ----- ---------------------
3020A/L,3120A 63 row.B.long.1.PAD63.I
3030A/L,3130A 79 row.B.long.1.PAD79.I
3042A/L,3142A 95 row.B.long.1.PAD95.I
3064A/L,3164A 119 row.B.long.1.PAD119.I
3090A/L,3190A 143 row.B.long.1.PAD143.I
3195A,3195L 175 row.B.long.1.PAD175.I

If one of these pips is used, the corresponding input to the part
will not be connected correctly internally. You can check to see
if the pip is used by calling up the design in EDITLCA, then typing
"find " followed by the pip name shown in the table above. You can
check to see if the input is used by typing "find PAD" followed by
the PAD number shown in the table above. Alternatively, you could
use the UNIX "grep" command to search for the pip name in the .lca

A patch is available from Xilinx that fixes this problem, and is being
shipped as soon as possible (this was written 8/1/94) to all

AR# 356
Date 03/31/1997
Status Archive
Type ??????
Page Bookmarked