Altera and VHDL library

Recent version of Quartus do not support user defined libraries. The only way is to add each file to the project separately (you can, of course, write a small tcl script that automates this task).

Avishay Orpaz.

Clemens Hermann wrote:

After

library

(e.g.

Hi Clemens,

There is no way Quartus can precompile a package (or a design entity) because it has to elaborate the package everytime it is being used. Thus, you will always have to keep the source code accessible. There's ways to encrypt the source code, but you will have to either use a code obfuscator or become part of Altera's AMPP program in order to encrypt the code in a way that Quartus can understand, but the rest of the world can't.

You could use a library directory and add this directory to your project. However, I don't believe the current versions support automatic filename inferencing for packages (i.e. if your package is called my_pkg, it will try to find my_pkg.vhd).

Also, the current version always compiles into library "work". As long as there's no namespace conflicts this is quite workable, but not quite what the LRM specifies. I have heard that version 5.0 will support named libraries.

Whether 5.0 also does automatic package filename inferencing is unclear to me. Hmmm.... would definitely be a wannahave...

Quartus II 5.0 is due out early May, so let's just wait and see.

Best regards,

Ben Twijnstra Sasco

You could change the library in the file properties tab with the GUI or with the following TCL command:

set_global_assignment VHDL_FILE my_pkg.vhd -líbrary my_lib

This works in QuartusII 4.2. The drawback is that a single file could NOT be in two libraries.

Regards Frank

Hi Clemens,

To use a package in multiple projects, the user must explicitly include the file containing the package in each project separately. (Quartus II does not auto-discover package files, only entity files.) The package file must be listed prior to its first use because Quartus II links VHDL design units during parsing. In Quartus II 5.1, we'll remove the requirement that VHDL source files be listed in the correct order. That way, users can simply add all their VHDL source files in any order, and we'll still process the design correctly.

Now, as for VHDL libraries: Prior to Quartus II 4.2, all user VHDL source files were compiled into the WORK library. In 4.2, we still compile VHDL source files into WORK by default, but we also added several mechanisms that allow the user to specify a different destination library. These mechanisms are described in the Quartus II Handbook, Chapter 6:

Hope this helps,

Subroto Datta Altera Corp.

Clemens Hermann wrote:

After

library

(e.g.

Hi Subroto,

first thanks to you and all the other people here helping me out!

o.k., there is stated:

Unlike the MAX+PLUS® II software and earlier versions of the Quartus II software, Quartus II software versions 2.1 and later do not support pre-compiled libraries.

was there a special reason (of course there was :P) to drop this feature?

When I write "my_lib" to File -> File Properties -> Library for the packages I want to be part of "my_lib" things work as desired. But the vhdl "library" is not reflected in the file system like new directory or similar. Am I right in the assumption that the library mechanism only allows to group elements in libraries within one single project and not to generate a library that then can be passed around and used in other projects _as Library_?

A last question: Is the library name I entered (as described above) as proberty of a VHDL file in any way related to libraries listed in Assignments -> Settings -> User Libraries?

Best regards and thanks again,

/ch

Hi Clemens,

Here are the replies to your questions.

"Unlike the MAX+PLUS=AE II software and earlier versions of the Quartus II software, Quartus II software versions 2.1 and later do not support pre-compiled libraries. Was there a special reason (of course there was :P) to drop this feature? "

We replaced the original VHDL and Verilog front-end in Quartus with a solution that couldn't support the pre compiled library feature, buth otherwise provided us with very robust language support, than what was present in prior versions of Quartus.

"When I write "my_lib" to File -> File Properties -> Library for the packages I want to be part of "my_lib" things work as desired. But the vhdl "library" is not reflected in the file system like new directory or similar. Am I right in the assumption that the library mechanism only allows to group elements in libraries within one single project and not to generate a library that then can be passed around and used in other projects _as Library_?"

You are correct. The Library field simply specifies the logical namespace for the design units in a file. Quartus does not support precompiled libraries, where the software would parse the design files and dump the parse trees into a specific directory, much like Modelsim. Instead, Quartus II parses design files on each invocation to quartus_map.exe; it doesn't store a representation of the parse trees on disk.

"A last question: Is the library name I entered (as described above) as proberty of a VHDL file in any way related to libraries listed in Assignments -> Settings -> User Libraries? "

No, it isn't. User Libraries are directories in which Quartus II searches for project source files. The naming of the feature is a bit unfortunate and historic. It should've been named Include Directories.

Hope this helps, Subroto Datta Altera Corp