mailboxes

I'm not sure about the errors you received (class not recognized) unless you either didn't pass the +sv switch to ncverilog (or use irun with a file with a .sv extension) or you were using a fairly old version (IUS58 or older).

However, there are some coding errors. You typically construct the mailbox outside the class and then pass the handle into the class via the new method.

module test;
 class mb_test;
   mailbox mbx_get;
   mailbox mbx_put;

   function new(mailbox m1, m2);
     mbx_int1 = m1;
     mbx_int2 = m2;
   endfunction

   // Code
 endclass :

 mb_test mailbox mb_in = new();
 mailbox mb_out = new();

 mb_test t = new(mb_in, mb_out);

endmodule


Hi Sebastian,
I suspect you have an old IUS version, do ncvlog -version

Here is a simple code that should work fine in NC, as a starting point.
program test(); mailbox mbx; initial begin mbx = new(); end endprogram

In your code you seem to be missing initial begin, but maybe you posted pseudo-code here.

Some old version didn't support mailbox and Cadence folks wrote a custom class for the same, you can try and find it in this forum, but I recommend you upgrade to latest release.

HTH
Ajeetha, CVC
www.noveldv.com

I'm not sure about the errors you received (class not recognized) unless you either didn't pass the +sv switch to ncverilog (or use irun with a file with a .sv extension) or you were using a fairly old version (IUS58 or older).

However, there are some coding errors. You typically construct the mailbox outside the class and then pass the handle into the class via the new method.

module test; class mb_test; mailbox mbx_get; mailbox mbx_put; function new(mailbox m1, m2); mbx_int1 = m1; mbx_int2 = m2; endfunction // Code endclass : mb_test mailbox mb_in = new(); mailbox mb_out = new(); mb_test t = new(mb_in, mb_out); endmodule <\code>

Hi,

thanks for the really fast and very very professional answers. A ncvlog -version says me, that my version is 5.7, which ist too old, isn't it?
Even your little testprogram does not compile, because the unrecognized option mailbox. I think, I should ask the system administrator for installing a newer version of systemverilog.

A basic question I have is the following: can I create a mailbox or any object inside a class? I think it is possible. The reason, I have declared the two mailboxes inside the class is, that I have two forever tasks, which read and write in these mailboxes.Even if it is bad programmig style, I would be interested, if it is possible.

Best regards
Sebastian

We addressed that exact topic almost exactly a year ago before we had support for classes. I did a search on mailboxes from this forum and found it. Go to http://www.cdnusers.org/Forums/tabid/52/view/topic/forumid/66/postid/2739/Default.aspx and you can find the discussion and an attachment that has the code for creating a mailbox class.

Tim

Thanks for your help.

I thougth, mailboxes are a genial invention, but actually I have problems over problems: I wanted to put an string into a mailbox, but it seems to me, that this isn't working, is that correct?
I'm really sorry about my silly questions, but there is no one else I could ask and I am really disappointed!

Another question is, how I can simulate a written program in SystemVerilog. I call ncvlog -SV filename.sv, but after that, no file for simulation is ready.
Could you help me???

Thanks for your patience!
Sebastian

Me again:

Thank you very much for the code examples, I'm trying to understand this code at the moment. You've helped me a lot.

Best wishes
Sebastian

>> Another question is, how I can simulate a written program in SystemVerilog.
>> I call ncvlog -SV filename.sv, but after that, no file for simulation is ready.

You need to elab and then simulate. Rather I believe the recommended approach going forward is to use the modern, more powerful "irun" command.

Try:


  irun my_file.sv


HTH
Ajeetha, CVC
www.noveldv.com