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Hello,
Pls see my attachment. There is a list of vhdl and bdf files under files.(e.g zpu.vhd, old_helloworld.vhd, ...see snapshots)
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I looked into your attachment. And the problem is that you have two entities with the same name. This is not desirable.
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Are these files automatically put into a work library??
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The files are compiled in the work library by the simulation software. Quartus II doesn't use work library etc for synthesis. However if you have a "design library" which contains design entities, then Quartus looks into the library for the particular design entity you have specified in your design.
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How to create a new library??
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Not required here.
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Create new folder in working directory???
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No.
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Now, to cut the long story short, here is what you should do:
1. If zpu.bdf and zpu.vhd represent the same design, remove either of these from your project Files.
2. If they represent two different designs, then change the name of one of them (i.e. change the name of the "entity" in the program and not the name of the file).
Regards,
Kumar Vijay Mishra.