THE COMPILER

The first thing that you have to do is set the current file as the project. To do this you select File and Project. You then click on the menu item Set Project To Current File (the short-cut for this is ctrl-shift-J). You can now start the compiler either by choosing the menu item Max+plus II -> Compiler or by going File -> Project -> Save & Compile (the short-cut for this is ctrl-L).

Now that the compiler is loaded you could click start and try to compile your file however you would likely not get too far. The crucial step is that you have to change the compiler from VHDL 1987 standard to VHDL 1993 standard. This is done by going to Interfaces -> VHDL Netlist Reader Settings and changing from VHDL 1987 to VHDL 1993 the following picture illustrates this:

figure 3.1

It is in this screen that you add any library files that should be compiled along with your code. If you need this feature read up in the Help file.

Now that you have setup which VHDL standard you will be using (this is extremely important) you are ready to start compiling your project. The compiler screen

figure 3.2

manages the compilation of your code. To start compiling you press the Start button. The first step in the compilation process is to run a check on your syntax. If the compiler finds something it did not like you will be notified and a message screen telling you how many errors and how many warnings it found during the syntax check.

figure 3.3

Another box is displayed it is entitled the Messages and is shown in figure 3.4. This includes a list of all of the errors, warnings, and informative messages that occurred during the compile. Anything in red is an error and must be fixed before your code can be successfully compiled. The message box is a crucial tool in the debugging process because it will tell you almost everything about your code (good and bad, usually bad though!). It is not only displayed when you are compiling but it also is displayed when you are doing simulations and timing analysis as well as other functions.

figure 3.4

You can scroll through the messages by either using the scroll bar or by using the Message button. If you have the text editor open and you click on a message and then click on Locate, the program will move you to the line which is giving the error. If you don't understand the message then click on the Help on Message button and it will open a Help screen which describes this message.

After you have successfully removed all of the syntax errors from the screen the compiler will continue through all of the stages necessary to make a downloadable file. This is a long process and may take upwards of 10 minutes for large designs. The compile process will produce a whole bunch of files each with it's own purpose. The help file is extremely good at describing all of the compiler attributes and you should use it often.

After you have successfully compiled your VHDL code you must now set the pin assignments.


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Mark Fedorak, Vera Casteel, Kris Pucci, Ron Smith - 1998