Re: [sv-ec] How do I record coverage information of Fibonacci series, using covergroup

Clear DayTapan,

What you are proposing is an interesting enhancement to the auto-bining capabilities of the language.
Currently, the way to specify non-consecutive bins is to use an explicit (user-defined) set of bins.
Pre-computing multiple sets of Fibinacci numbers and selecting the appropriate one via a compiler 
directive ('ifdef) is a possible way to implement this. A generate statement might be another possibility, 
but I believe it is harder to get that working for this particular purpose.

    Arturo

----- Original Message ----- 
From: Tapan Kapoor 
To: sv-ec@eda.org 
Cc: Sandeep Pagey 
Sent: Friday, July 01, 2005 1:05 AM
Subject: [sv-ec] How do I record coverage information of Fibonacci series, using covergroup


Hi,

The question is about System Verilog covergroup usage. How to record coverage information of any design signal which has a non-continuous spectrum like Fibonacci series? The range of Fibonacci series is configurable through parameters i.e. two parameter MIN_VAL and MAX_VAL. These parameters provide bounds for the value-distribution of the signal, which means the range would differ from application to application. If I use whole range in the bin definition, as shown in the code fragment below:
-----------------------------------------------
integer fib_signal;
always @ (input_data)
        fib_signal = input_data;

covergroup fibonacci_cover @ (posedge clock)
        rec: coverpoint fib_signal
        {
            bins data[] = {[MIN_VAL:MAX_VAL]};
        }
endgroup
------------------------------------------------
the numbers which are not in the fibonacci series appear as holes, since they are never likely to appear. Alternatively, if there were a construct to define bin-range through a function as below:
----------------------
    bins data[] = fibonacci_function(MIN_VAL, MAX_VAL)
----------------------
where the function "fibonacci_function" is repetitively invoked to get all the fibonacci values within the range, it would help defining the range accurately. 

Please suggest if there is a way to code the above-described functionality within the existing language. OR is it possible to include the above sort of construct in the covergroup. It would be useful for many other application where the input data-stream is non-continuous spectrum like recording even-parity, odd-parity, one-hot etc.


Thanks & regards,

Sandeep / Tapan. 


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