Thanks all,
JustJohn XST has been improved a lot from the version 6.1 to 7.1.
2 years ago you tryed XST 5.1 maybe or 6.1.....
I found XST (ISE 7.1) much improved but I'm not 100% happy.


Alan thanks for your answer is very important to me.

Thanks again all,
Francesco
PS: I hope to have some feedback from Xilinx about that :-)

Francesco,

Two years ago I tried the same exercise. I took another group's code,
enough VHDL to fill an XC2V3000, which would compile under Synplify,
and tried to port it to XST. I won't go into details, but I finally had
to give up the effort. I suspect part of the problem may have been that
the original code was _very_ strict about using unconstrained arrays in
_any_and_every_ place it was possible to do so. This means a lot of
work for the tool (not to mention the writer).

Here is a link to a very fair, and not too old, article on 'free'
tools, like XST, vs. expensive tools like Synplify:
http://www.fpgajournal.com/articles_2005/20050322_freetool.htm
Quoting from that:
"First (at this stage anyway), the commercial EDA tools seem to have an
edge in the robustness and versatility in their language front-end. If
you don't write perfect, mainstream-style HDL, a commercial tool will
often do a better job making some sense of your code and yielding
reasonable results than the current crop of vendor-proprietary tools."

Personally, I code to XST, on the assumption that if it makes it there,
it'll play anywhere.

Hi Francesco,

I've recently used XST without problems on a Spartan-II with 99% logic
utilisation.
That's using VHDL. Max. clock speed was 100Mhz. So XST gets my vote.

Alan



francesco_poderico@yahoo.com wrote:
> Hi all,
> I wish to have an idea about how many people here uses Synlify or
> Leonardo and how many people uses XST.
> The purpose of that is undesrtand how many people here beleave that XST
> is a mature product and it can be trusted or not.
> At moment I'm tryng to use XST for a small FPGA (spartan 2E 150) and
> I'm having a lot of trouble.
> (I have several years of experience and I made design very complex)
>
> For example the xapp807 has source file in VHDL and in Verilog. when I
> use the verilog version it works fine, but when I use the VHDL version
> it is unrelaible. 
> 
> Hope to have feedback from you.
> Francesco

Hi all,
I wish to have an idea about how many people here uses Synlify or
Leonardo and how many people uses XST.
The purpose of that is undesrtand how many people here beleave that XST
is a mature product and it can be trusted or not.
At moment I'm tryng to use XST for a small FPGA (spartan 2E 150) and
I'm having a lot of trouble.
(I have several years of experience and I made design very complex)

For example the xapp807 has source file in VHDL and in Verilog. when I
use the verilog version it works fine, but when I use the VHDL version
it is unrelaible. 

Hope to have feedback from you.
Francesco