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AR# 15958

5.1i iMPACT - Verification of a Virtex-II/Pro device generates "ERROR:Bitstream:63 - Trying to read past end of bitstream..."


General Description:

When I attempt to program and verify a Virtex-II/Pro device, the following error message is reported:

"5.1i iMPACT: ERROR:Bitstream:63 - Trying to read past end of bitstream. The bitstream may be corrupted."

iMPACT crashes after the error is reported.


This problem is fixed in the latest 5.1i Service Pack, available at:

The first service pack containing the fix is 5.1i Service Pack 3.

Additionally, you can work around most instances of this problem by generating the .msk and .bit files in separate BitGen runs.

AR# 15958
Date Created 09/03/2007
Last Updated 12/15/2012
Status Active
Type General Article