How to get handle for a coverpoint?

Question

How can I get a handle for a coverpoint so that I can call methods using that handle? First I need to know the type of a coverpoint so that I can instantiate the handle.

Here is an example:

class my_coverage_class;
  rand bit my_coverpoint;
  covergroup my_covergroup;
    option.per_instance = 1;
    coverpoint my_coverpoint;
  endgroup
  function new;
    my_covergroup = new;
  endfunction
endclass: my_coverage_class

program automatic testbench;
  initial begin
    my_coverage_class inst = new();
    begin 
      var type(inst.my_covergroup.my_coverpoint) cp
        = inst.my_covergroup.my_coverpoint; // BREAKS HERE
      cp.get_inst_coverage();
    end
  end
endprogram // testbench

When I run the above using VCS 2013.06, I get:

Error-[NYI] Not Yet Implemented
testbench, 16
Feature is not yet supported: Type operator not supported

Note: When I run $display("%s", $typename(inst.my_covergroup.my_coverpoint)), I get <unknown>

Greg · Accepted Answer · 2017-12-18T21:46:43.983

Based on the error message, your simulator does not yet support type. Even if it did, I don't see anything IEEE Std 1800-2012 that suggest there can be a handle to a coverpoint. If your simulator supports handles for covergorups, then you should be able to do the following:

package my_package;
  covergroup my_cover_group(bit cp);
    option.per_instance = 1;
    coverpoint cp;
  endgroup
  class my_coverage_class;
    rand bit my_coverpoint;
    my_cover_group my_covergroup;
    function new;
      this.my_covergroup = new(this.my_coverpoint);
    endfunction
  endclass: my_coverage_class
endpackage : my_package

program automatic testbench;
  import my_package::*;
  my_cover_group covgrp_handle;
  initial begin
    my_coverage_class inst = new();
    begin 
      covgrp_handle = inst.my_covgrp;
      covgrp_handle.cp.get_inst_coverage();
    end
  end
endprogram // testbench

Other options is to use a macro (ex: `define cp inst.my_covergroup.my_coverpoint). This would work for the provided test case, however it is not very flexible if intended for dealing with many (possibly unique) types of instances/covergroups/coverpoints.

How to get handle for a coverpoint?

1 Answers1