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TRANSITION BINS
Transitional functional point bin is used to examine the legal transitions of a value. SystemVerilog allows to specifies one or more sets of ordered value transitions of the coverage point.
Type of Transitions:
Single Value Transition
Sequence Of Transitions
Set Of Transitions
Consecutive Repetitions
Range Of Repetition
Goto Repetition
Non Consecutive Repetition
Single Value Transition
Single value transition is specified as:
value1 => value2
program main;
bit [0:3] y;
bit [0:2] values[$]= '{3,5,6};
covergroup cg;
cover_point_y : coverpoint y {
bins tran_34 = (3=>4);
bins tran_56 = (5=>6);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
In the above example, 2 bins are created for covering the transition of point "y" from 3 to 4 and other for 5 to 6. The variable y is given the values and only the transition 5 to 6 is occurring.
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 2
Covered : 1
Percent: 50.00
Uncovered bins
------------------
tran_34
Covered bins
----------------
tran_56
Sequence Of Transitions
A sequence of transitions is represented as:
value1 => value3 => value4 => value5
In this case, value1 is followed by value3, followed by value4 and followed by value5. A sequence can be
of any arbitrary length.
program main;
bit [0:3] y;
bit [0:2] values[$]= '{3,5,6};
covergroup cg;
cover_point_y : coverpoint y {
bins tran_345 = (3=>4>=5);
bins tran_356 = (3=>5=>6);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
In the above example, 2 bins re created for covering the transition of point "y" from 3 to 4 to 5 and other for 3 to 5 to 6. The variable y is given the values and only the transition 3 to 5 to 6 is occurring.
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 2
Covered : 1
Percent: 50.00
Uncovered bins
------------------
tran_345
Covered bins
-----------------
tran_356
Set Of Transitions
A set of transitions can be specified as:
range_list1 => range_list2
program main;
bit [0:3] y;
bit [0:2] values[$]= '{3,5,6};
covergroup cg;
cover_point_y : coverpoint y {
bins trans[] = (3,4=>5,6);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
In the above example, bin trans creates 4 bin for covering 3=>5,4=>5,3=>6 and 4=>6.
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 4
Covered : 1
Percent: 25.00
Uncovered bins
------------------
tran_34_to_56:3->6
tran_34_to_56:4->5
tran_34_to_56:4->6
Covered bins
----------------
tran_34_to_56:3->5
Consecutive Repetitions
Consecutive repetitions of transitions are specified using
trans_item [* repeat_range ]
Here, trans_item is repeated for repeat_range times. For example,
3 [* 5]
is the same as
3=>3=>3=>3=>3
program main;
bit [0:3] y;
bit [0:2] values[$]= '{3,3,3,4,4};
covergroup cg;
cover_point_y : coverpoint y {
bins trans_3 = (3[*5]);
bins trans_4 = (4[*2]);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 2
Covered : 1
Percent: 50.00
Uncovered bins
------------------
trans_3
Covered bins
----------------
trans_4
Range Of Repetition
An example of a range of repetition is:
3 [* 3:5]
is the same as
3=>3=>3, 3=>3=>3=>3, 3=>3=>3=>3=>3
program main;
bit [0:3] y;
bit [0:2] values[$]= '{4,5,3,3,3,3,6,7};
covergroup cg;
cover_point_y : coverpoint y {
bins trans_3[] = (3[*3:5]);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
In the above example, only the sequence 3=>3=>3=>3 is generated. Other expected sequences 3=>3=>3 and 3=>3=>3=>3=>3 are not generated.
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 3
Covered : 1
Percent: 33.33
Uncovered bins
------------------
tran_3:3[*3]
tran_3:3[*5]
Covered bins
----------------
tran_3:3[*4]
Goto Repetition
The goto repetition is specified using: trans_item [-> repeat_range]. The required number of occurrences of a particular value is specified by the repeat_range. Any number of sample points can occur before the first occurrence of the specified value and any number of sample points can occur between each occurrence of the specified value. The transition following the goto repetition must immediately follow the last occurrence of the repetition.
For example:
3 [-> 3]
is the same as
...=>3...=>3...=>3
where the dots (...) represent any transition that does not contain the value 3.
A goto repetition followed by an additional value is represented as follows:
1 => 3 [ -> 3] => 5
is the same as
1...=>3...=>3...=>3 =>5
program main;
bit [0:3] y;
bit [0:2] values[$]= '{1,6,3,6,3,6,3,5};
covergroup cg;
cover_point_y : coverpoint y {
bins trans_3 = (1=>3[->3]=>5);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 1
Covered : 1
Percent: 100.00
Non Consecutive Repetition
The nonconsecutive repetition is specified using: trans_item [= repeat_range]. The required number of occurrences of a particular value is specified by the repeat_range. Any number of sample points can occur before the first occurrence of the specified value and any number of sample points can occur between each occurrence of the specified value. The transition following the nonconsecutive repetition may occur after any number of sample points so long as the repetition value does not occur again.
For example:
3 [= 2]
is same as
...=>3...=>3
A nonconsecutive repetition followed by an additional value is represented as follows:
1 => 3 [=2] => 5
is the same as
1...=>3...=>3...=>5
program main;
bit [0:3] y;
bit [0:2] values[$]= '{1,6,3,6,3,6,5};
covergroup cg;
cover_point_y : coverpoint y {
bins trans_3 = (1=>3[=2]=>5);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 1
Covered : 1
Percent: 100.00
Transitional functional point bin is used to examine the legal transitions of a value. SystemVerilog allows to specifies one or more sets of ordered value transitions of the coverage point.
Type of Transitions:
Single Value Transition
Sequence Of Transitions
Set Of Transitions
Consecutive Repetitions
Range Of Repetition
Goto Repetition
Non Consecutive Repetition
Single Value Transition
Single value transition is specified as:
value1 => value2
program main;
bit [0:3] y;
bit [0:2] values[$]= '{3,5,6};
covergroup cg;
cover_point_y : coverpoint y {
bins tran_34 = (3=>4);
bins tran_56 = (5=>6);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
In the above example, 2 bins are created for covering the transition of point "y" from 3 to 4 and other for 5 to 6. The variable y is given the values and only the transition 5 to 6 is occurring.
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 2
Covered : 1
Percent: 50.00
Uncovered bins
------------------
tran_34
Covered bins
----------------
tran_56
Sequence Of Transitions
A sequence of transitions is represented as:
value1 => value3 => value4 => value5
In this case, value1 is followed by value3, followed by value4 and followed by value5. A sequence can be
of any arbitrary length.
program main;
bit [0:3] y;
bit [0:2] values[$]= '{3,5,6};
covergroup cg;
cover_point_y : coverpoint y {
bins tran_345 = (3=>4>=5);
bins tran_356 = (3=>5=>6);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
In the above example, 2 bins re created for covering the transition of point "y" from 3 to 4 to 5 and other for 3 to 5 to 6. The variable y is given the values and only the transition 3 to 5 to 6 is occurring.
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 2
Covered : 1
Percent: 50.00
Uncovered bins
------------------
tran_345
Covered bins
-----------------
tran_356
Set Of Transitions
A set of transitions can be specified as:
range_list1 => range_list2
program main;
bit [0:3] y;
bit [0:2] values[$]= '{3,5,6};
covergroup cg;
cover_point_y : coverpoint y {
bins trans[] = (3,4=>5,6);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
In the above example, bin trans creates 4 bin for covering 3=>5,4=>5,3=>6 and 4=>6.
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 4
Covered : 1
Percent: 25.00
Uncovered bins
------------------
tran_34_to_56:3->6
tran_34_to_56:4->5
tran_34_to_56:4->6
Covered bins
----------------
tran_34_to_56:3->5
Consecutive Repetitions
Consecutive repetitions of transitions are specified using
trans_item [* repeat_range ]
Here, trans_item is repeated for repeat_range times. For example,
3 [* 5]
is the same as
3=>3=>3=>3=>3
program main;
bit [0:3] y;
bit [0:2] values[$]= '{3,3,3,4,4};
covergroup cg;
cover_point_y : coverpoint y {
bins trans_3 = (3[*5]);
bins trans_4 = (4[*2]);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 2
Covered : 1
Percent: 50.00
Uncovered bins
------------------
trans_3
Covered bins
----------------
trans_4
Range Of Repetition
An example of a range of repetition is:
3 [* 3:5]
is the same as
3=>3=>3, 3=>3=>3=>3, 3=>3=>3=>3=>3
program main;
bit [0:3] y;
bit [0:2] values[$]= '{4,5,3,3,3,3,6,7};
covergroup cg;
cover_point_y : coverpoint y {
bins trans_3[] = (3[*3:5]);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
In the above example, only the sequence 3=>3=>3=>3 is generated. Other expected sequences 3=>3=>3 and 3=>3=>3=>3=>3 are not generated.
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 3
Covered : 1
Percent: 33.33
Uncovered bins
------------------
tran_3:3[*3]
tran_3:3[*5]
Covered bins
----------------
tran_3:3[*4]
Goto Repetition
The goto repetition is specified using: trans_item [-> repeat_range]. The required number of occurrences of a particular value is specified by the repeat_range. Any number of sample points can occur before the first occurrence of the specified value and any number of sample points can occur between each occurrence of the specified value. The transition following the goto repetition must immediately follow the last occurrence of the repetition.
For example:
3 [-> 3]
is the same as
...=>3...=>3...=>3
where the dots (...) represent any transition that does not contain the value 3.
A goto repetition followed by an additional value is represented as follows:
1 => 3 [ -> 3] => 5
is the same as
1...=>3...=>3...=>3 =>5
program main;
bit [0:3] y;
bit [0:2] values[$]= '{1,6,3,6,3,6,3,5};
covergroup cg;
cover_point_y : coverpoint y {
bins trans_3 = (1=>3[->3]=>5);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 1
Covered : 1
Percent: 100.00
Non Consecutive Repetition
The nonconsecutive repetition is specified using: trans_item [= repeat_range]. The required number of occurrences of a particular value is specified by the repeat_range. Any number of sample points can occur before the first occurrence of the specified value and any number of sample points can occur between each occurrence of the specified value. The transition following the nonconsecutive repetition may occur after any number of sample points so long as the repetition value does not occur again.
For example:
3 [= 2]
is same as
...=>3...=>3
A nonconsecutive repetition followed by an additional value is represented as follows:
1 => 3 [=2] => 5
is the same as
1...=>3...=>3...=>5
program main;
bit [0:3] y;
bit [0:2] values[$]= '{1,6,3,6,3,6,5};
covergroup cg;
cover_point_y : coverpoint y {
bins trans_3 = (1=>3[=2]=>5);
}
endgroup
cg cg_inst = new();
initial
foreach(values[i])
begin
y = values[i];
cg_inst.sample();
end
endprogram
Coverage report:
--------------------
VARIABLE : cover_point_y
Expected : 1
Covered : 1
Percent: 100.00
Index
Introduction
Cover Group
Sample
Cover Points
Coverpoint Expression
Generic Coverage Groups
Coverage Bins
Explicit Bin Creation
Transition Bins
Wildcard Bins
Ignore Bins
Illegal Bins
Cross Coverage
Coverage Options
Coverage Methods
System Tasks
Cover Property
Report a Bug or Comment on This section - Your input is what keeps Testbench.in improving with time!
Introduction
Cover Group
Sample
Cover Points
Coverpoint Expression
Generic Coverage Groups
Coverage Bins
Explicit Bin Creation
Transition Bins
Wildcard Bins
Ignore Bins
Illegal Bins
Cross Coverage
Coverage Options
Coverage Methods
System Tasks
Cover Property
Report a Bug or Comment on This section - Your input is what keeps Testbench.in improving with time!