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Visitor
Visitor
5,973 Views
Registered: ‎12-08-2010

FFT 7.1 error

Hello,

 

  I am using Matlab 2009b, simulink platform ans xilinx blockset.

  I need to use FFT 7.1 for my design and I met some problems during the simulation that I don't understand

  I've added a screenshot of the simulation and the problem occured.

  Waiting for your assistance

 

Arik Tomer

 

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temppeoblem.JPG
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6 Replies
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Xilinx Employee
Xilinx Employee
5,966 Views
Registered: ‎11-28-2007

The error message is pretty clear: you have undriven inputs (highlighted in red) on the FFT core. If you don't plan to use those inputs, connect them to appropiate constants. The blog below has a SysGen FFT example which you can take a look:

 

http://myfpgablog.blogspot.com/2010/07/fft-results-from-matlab-fft-bit.html

 

 

 

 


@d04110 wrote:

Hello,

 

  I am using Matlab 2009b, simulink platform ans xilinx blockset.

  I need to use FFT 7.1 for my design and I met some problems during the simulation that I don't understand

  I've added a screenshot of the simulation and the problem occured.

  Waiting for your assistance

 

Arik Tomer

 


 

Cheers,
Jim
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Visitor
Visitor
5,956 Views
Registered: ‎12-08-2010

But it's connected to a constant..... you can see in the picture

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Xilinx Employee
Xilinx Employee
5,950 Views
Registered: ‎11-28-2007

The FFT core shown in your picture has 7 input ports and you only connected 3. All input ports need to be driven. The undriven ones are highlighted in red like this > (xn_im for example).

 

 


@d04110 wrote:

But it's connected to a constant..... you can see in the picture


 

Cheers,
Jim
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Visitor
Visitor
5,895 Views
Registered: ‎12-08-2010

It doesn't help...

We tried to drive every input with every constant and even tried the recommended solution (placed the parts exactly like in the picture)

here is another screen shot of the situation - I don't know what to do here

temppeoblem.JPG
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Visitor
Visitor
5,893 Views
Registered: ‎12-08-2010

 
problem2.JPG
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Xilinx Employee
Xilinx Employee
5,876 Views
Registered: ‎11-28-2007

It did help as now you're getting a different error message. I suggest you keep reading the error message until you understand what it means and then think about what needs to be done to fix it. You may need to go over some of the SysGen tutorials with simpler examples (check the link below) so you can understand how SysGen and fixed point works before tackling a bigger project.

 

http://forums.xilinx.com/t5/DSP-Tools/Available-System-Generator-Documentation/td-p/52551

 

 

 


@d04110 wrote:

It doesn't help...

We tried to drive every input with every constant and even tried the recommended solution (placed the parts exactly like in the picture)

here is another screen shot of the situation - I don't know what to do here


 

 

Cheers,
Jim
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