Range Value Direction ?

Further to Ray's email on "usage of Covergroup variables"...we have few
more questions

In following

Coverpoint int_var
{
        bins a = {[4:2]);
        bins aa[4] = {[10:5]};
        bins b[0] = { 1, 2, 3};
        bins c[100] = { 1, 2, 3};
        
}

1) Is the range "[4:2]" of bin "a" legal ?
2) If bin "aa" is legal then how are values distributed ? Are range
values directional ?
Will "aa[0]" have "10" or "5" ?
3) Is bin "b" legal ? Is it okay to have bin size := 0 ?
4) Is bin "c" legal ? Can some bins have no values associated with them
? What value is to be used for coverage calculation "100" or "Number of
bins with value" ?

Thanks,
++swapnil

-----Original Message-----
From: Ryan, Ray
Sent: Monday, October 25, 2004 9:57 AM
To: sv-ec@eda.org
Cc: Scott, David; Dwivedi, Swapnil; Yum, Sunny
Subject: usage of overgroup variables

We would appreciate some clarification on the usage of Covergroup
variables.

Covergroup variable usage:
1) Can a covergroup variable be created (ie assigned 'new') other than
as a part of the declaration of the variable?
2) Can NULL be assigned to a covergoup variable?
3) Can a covergroup variable be assigned 'new' more than once?
4) Can a covergroup variable be assigned another covergroup variable?
5) Can a covergroup be a parameter to a task or function? Are there any
limits on the direction?
6) Can a function return a covergroup (ie the function return type is a
covergroup)?

Coverage Data lifetime:
7) If a covergroup instance is deleted or goes out of scope, is it's
coverage data still included in the type coverage? A covergroup instance
might go out of scope or be deleted when:
    a) The covergroup variable is assigned NULL (if allowed).
    b) The instance variable is declared and assigned new in a class
       and the class instance is assigned NULL.
    c) The covergroup variable is declared within a task or function.
       In this case, each time the task or function is entered, is
       additional type coverage data accumulated?

Thanks,
Ray
Received on Thu Oct 28 17:07:48 2004