Hi,

I have a fully routed Spartan3(Alliance 9,2) that I would like to keep 
the routing and only change the "IOB Input Switching Characteristic" for 
all used IOs, I know how to do this in the FPGA Editor but I would like 
to do this using a new "ucf" file.

The reason is that I have some issues and like to try out different 
Characteristics.

Anyone know how to do this?

/michael

On Mar 28, 5:37=A0am, Michael <michael_laaja...@yahoo.com> wrote:
> Hi,
>
> I have a fully routed Spartan3(Alliance 9,2) that I would like to keep
> the routing and only change the "IOB Input Switching Characteristic" for
> all used IOs, I know how to do this in the FPGA Editor but I would like
> to do this using a new "ucf" file.
>
> The reason is that I have some issues and like to try out different
> Characteristics.
>
> Anyone know how to do this?
>
> /michael

Going back the UCF file to make this change means that you need start
the design implementation over from the map and that could mean
changes in your placement and routing. The MAP and PAR tools do offer
the option to use a previous NCD file to guide the the mapping and
placement.

For both MAP and PAR this would be "-gf my_old.ncd -gm exact".  The "-
gf" is the Guide File and the "-gm" is the Guide Mode.

Using FPGA Editor will be far easier to accomplish what you want to do
and you don't need to do everything through the GUI.  Use the GUI the
first time to get the commands to select an IOB and change the
IOSTANDARD and then create a text file to replicate these commands
across all of your IOBs.  You can run this script using the non-GUI
version by using the fpga_edline tool instead of fpga_editor.

fpga_edline -p my_script.txt my_design.ncd

Don't forget to add a save command to write the NCD at the end before
quitting.

Ed McGettigan
--
Xilinx Inc.

Hi,

On 03/28/11 04:37 PM, Ed McGettigan wrote:
> On Mar 28, 5:37 am, Michael<michael_laaja...@yahoo.com>  wrote:
>> Hi,
>>
>> I have a fully routed Spartan3(Alliance 9,2) that I would like to keep
>> the routing and only change the "IOB Input Switching Characteristic" for
>> all used IOs, I know how to do this in the FPGA Editor but I would like
>> to do this using a new "ucf" file.
>>
>> The reason is that I have some issues and like to try out different
>> Characteristics.
>>
>> Anyone know how to do this?
>>
>> /michael
>
> Going back the UCF file to make this change means that you need start
> the design implementation over from the map and that could mean
> changes in your placement and routing. The MAP and PAR tools do offer
> the option to use a previous NCD file to guide the the mapping and
> placement.
No I don't like to do like that.
>
> For both MAP and PAR this would be "-gf my_old.ncd -gm exact".  The "-
> gf" is the Guide File and the "-gm" is the Guide Mode.
>
> Using FPGA Editor will be far easier to accomplish what you want to do
> and you don't need to do everything through the GUI.  Use the GUI the
> first time to get the commands to select an IOB and change the
> IOSTANDARD and then create a text file to replicate these commands
> across all of your IOBs.  You can run this script using the non-GUI
> version by using the fpga_edline tool instead of fpga_editor.
>
> fpga_edline -p my_script.txt my_design.ncd
>
> Don't forget to add a save command to write the NCD at the end before
> quitting.
>
> Ed McGettigan
> --
> Xilinx Inc.
>
>
Ok, that sounds like the best way thanks!!

/michael