Hey everybody,

Just started using Xilinx XST as my synthesis tool and I'm just
looking for the command line instruction (or GUI) to set the design
frequency, I was using precision where it was "setup_design -
frequency=66".

Anyone know the equivalent command for XST?

My eyes cant seem to find it in the documentation! :-(


Cheers,


Rob.

r...@gmail.com wrote:

> Just started using Xilinx XST as my synthesis tool and I'm just
> looking for the command line instruction (or GUI) to set the design
> frequency, I was using precision where it was "setup_design -
> frequency=66".

To learn the tool, just give ISE
a known good synchronous hdl design file.
It will tell you what Fmax is,
and draw you an rtl schematic.

Then read the docs and the command files it made.

         -- Mike Treseler

<r...@gmail.com> wrote in message 
news:b...@a70g2000hsh.googlegroups.com...
> Hey everybody,
>
> Just started using Xilinx XST as my synthesis tool and I'm just
> looking for the command line instruction (or GUI) to set the design
> frequency, I was using precision where it was "setup_design -
> frequency=66".
>
> Anyone know the equivalent command for XST?
>
> My eyes cant seem to find it in the documentation! :-(
>
>
> Cheers,
>
>
> Rob.

UCF file?

NET "clk" TNM_NET = "clk";
TIMESPEC "TS_clk" = PERIOD "clk" 0.025 us;

Hans
www.ht-lab.com

Rob wrote:
>
> I'm just looking for the command line instruction (or GUI)
> to set the design frequency, I was using precision where it
> was "setup_design -frequency=66".
>
> Anyone know the equivalent command for XST?
>

XST timing constraints are set up in the .xcf file

In the 9.2i XST user manual
  %xilinx%\doc\usenglish\books\docs\xst\xst.pdf

Look at:
  "XST Constraint File (XCF)", page 325
  "XST timing options", page 336

The XST command line field is described in the
first section listed above.

In the ISE GUI, you add this file to the flow by:

 - right click on the "Synthesis - XST " line of
   the processes window, and select "Properties"

 - in the "Synthesis Options" category:
   - set "Property Display Level" to "Advanced"
   - check the "Use Synthesis Constraints" button
   - fill in the "Synthesis Constraints File" field

 If you want XST to forward annotate these to P&R tools,
also check the "Write Timing Constraints" option.

Brian