Error: top level design entity " " is undefined

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hello, I met with the same question,

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As FvM indicated this error message is caused by the fact that no VHDL entity is found with the name of the "top level entity". It is not enough to name your VHDL file with the name of the top entity. The top entity itself of your VHDL description should have this name.

e.g. In the example below TOP is the "Top Level Entity" and has been declare d like that (see @pletz) file TOP.vhd

entity TOP is

port (

...

);

end TOP;

architecture my_design of TOP is

begin

...

end my_design;

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we have problem in compiling VHDL code in Quartus II software. Every time we compile it shows the Error:top level design entity " file name" is undefined.

We are even taking care of the case sensitivity.

Our file name, new created project name and entity name in the code are all same.

Plz help us regarding this.

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Hi,

did you set the toplevel correctly ? You can check that in Quartus :

Assignments -> Device -> General

Look to the field "Toplevel entity". If this is not your toplevel, write it down here.

Kind regards

I solved this in Quartus II 11.0 by going Assignments > Settings > General and making my Top-level entity the name of my top level Verilog module (not its filename).

e.g. for a file named example.v

module circuit (output f, input x,y,z);

assign f=(x|(y&~z))&~(y&z);

endmodule

make the Top-level entity "circuit" not "example"

Hi,

thanks for the reply..

I tried to check the top level entity in the way u said but it is the same name as in program. It is all in small case.

Still there is undefined top level entity error.

Should the file name be in small case also?

Is it got to do with the location of the file where it is stored?

Thanks

Hi...

Thanks for the reply....

There is no space character in the name.

Is there any specific location like 'bin' folder where the files has to be stored while simulating the program?

Please help me with this..

Thanks

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Hi...

Thanks for the reply....

There is no space character in the name.

Is there any specific location like 'bin' folder where the files has to be stored while simulating the program?

Please help me with this..

Thanks

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Hi,

you can check whether the file is in the project or not.

Project -> Add/Remove Files in Project

There you can see all the files which are used in the project.

If you don't see your top-level files use the "add" button to include the file.

Btw: Did you use the Project wizard for setting up your project ?

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The said error message means, that no entity with the said top-level name can be found in any of the design files, the error can clearly be distinguished from file not found.

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Hi FvM,

when the top-level file isn't in the file list, you don't get any message about a missing file.

Did you get a warning like this during Analysis and Elaboration ?

Warning: Can't analyze file -- file C:/altera/quartus80sp1/qdesigns/vhdl_verilog_tutorial/addersubtractor.vhd is missing