System Verilog Mailbox Usage

SystemVerilog
,
1

I am new to using SV mailboxes.

I declare a mailbox in a testbench module - driver.sv

mailbox evt_mbx = new ();

Then I add data to it:

evt_mbx.put (mailbox_data);

This seems to work fine.

In another Testbench module elg_bfm.sv I now want to read the mailbox.

How do I reference the evt_mbx mailbox created in the other module?

My simulator is giving me this error

Unresolved reference to ‘evt_mbx’

initial
begin
forever begin
      int idx;
      #2 evt_mbx.get (idx);
 end
end

Thanks

Len

2

In reply to liguydp:

module is mainly for RTL design, if you want to pass stuff… just input output …
mailbox is for testbench, most case is declare under class.

3

In reply to liguydp:

You declared evt_mbx as a class variable inside a module, and initialized it with a handle to a mailbox object. You can access that handle value from another module the same as you would access another int variable from another module: either by hierarchical reference, or through port connections. You just need to make sure you construct the mailbox in one place, and pass the handle to where it being used.

module driver;
mailbox #(int)  evt_mbx;
...
   evt_mbx.put(...)
endmodule
module elg_bfm;
mailbox #i(nt)  evt_mbx;
...
   evt_mbx.get(...);
endmodule

module top;

mailbox #(int)  evt_mbx = new ();

driver d1();
bfm b1();
initial begin
   d1.evt_mbx = evt_mbx;
   b1.evt_mbx = evt_mbx;
end
endmodule




module driver(input mailbox #(int) mbx);
...
   mbx.put(..._;
endmodule
module elg_bfm(mailbox #(int) mbx);
...
   mbx.get(...);
endmodule

module top;

mailbox #(int)  evt_mbx = new ();

driver d1(et_mbx);
bfm b1(evt_mbx);
endmodule