I am currently working on an old board which have old FPGA SPRTAN which its not available on market on board and i dont have a source code for those FPGA's except for .bit
file which was downloaded through VME bus.

Currently i am redesigning the board eliminating all the PAL's on the
board with high end FPGA and also want to incorporate the obsolescence
spartan into them.But i dont have a source code except for .BIT
(Bitstream)file.

Is there any software which could convert the .bit file to VHDL/
Verilog?or even a functional block?

Any alternative suggestions to go ahead with this board redesign ?

Thank you
osama

I think you're going to struggle with that - the bitstream format has never been formally documented.

Some reading for you :) - you may already have seen them?

https://www.fpgarelated.com/showthread/comp.arch.f...

https://ai2-s2-pdfs.s3.amazonaws.com/e4df/deaa6f68...

http://www.fabienm.eu/flf/wp-content/uploads/2014/...

Cheers,

Martin

thanks