Re: Flame Linus to a crisp!

[Timothy Miller]

Linus Torvalds wrote:

>On Thu, 24 Apr 2003, Timothy Miller wrote:
>  
>
>>For their smaller devices, Xilinx has a free "WebPack" which is a 
>>complete Verilog synthesizer (I don't know if it does VHDL), as well as 
>>place & route, of course.  I think it'll do up to Virtex II 250.  It 
>>also tends use fewer gates for a given design than the version of 
>>Leonardo Spectrum we have.  It just doesn't have a simulator, which is 
>>vital to any good development process.  Also, the Web Pack only runs 
>>under Windows.  Maybe it'll work with WINE?
>>    
>>
>
>It does work with wine - but it's sad how horrible the command line tools
>are (they were apparently first done under UNIX, and then ported to 
>Windows, and they got the Windows command line interface and trying to use 
>them in a sane way with Wine is not exactly much fun).
>
>But yes, with Wine and a few scripts you can actually make the tools 
>usable under Linux - I tried them out and had a small silly "pong" game 
>running on one of those things (a 100k device on one of the cheap 
>development boards).
>
>I have to admit that I would hate to actually use those tools for any real 
>work, though. 
>
>  
>
Where I work we have used the Web Pack (5.1, I believe) for "real work", 
although you can't trust its static timing.  Beyond a certain 
utilization, it completely lies to you, and we can't get it to work 
right, no matter how much we over-constrain a design.  All we can do is 
synthesize and then thoroughly test in real hardware (which isn't hard 
to do when all you're doing is a simple pixel-processing pipeline -- 
either it works, or you get obvious sprinkless all over the monitor 
screen).  If that doesn't work, we get really clever to reduce area, or 
we go to a bigger device.  What can you do with free but closed-source 
software?  :)  Designing for FPGA's is a real pain.  Although the ASIC I 
did was a lot more complex, the process was a lot more straight-forward 
and the tools didn't lie to you.