4 

2.1  Line Coverage

Line coverage simply answers the question, "Was this line of code executed during simulation?"

Covered will display the number of logical lines of code that exist in a particular file with the number of logical lines that were executed during the simulation along with a percentage indicating the percentage of lines executed. If verbose mode is selected for a report, Covered will display the lines of logic that were not executed during the simulation run.

2.1.1 Example

Example

Suppose that the following module was specified in your DUT that is being analyzed:

        module test;

        reg a, b, c;

        initial
          begin
           a = 0;    // Line 1
           b = 1;    // Line 2
           if( a )
             c = b;  // Line 3
           else
             c = ~b; // Line 4
          end

        endmodule

If this code were simulated as stated, the simulator would execute lines 1 and 2, and due to the value assigned to a, line 4 would be executed. This means that during execution, out of a possibility of 4 lines, only 3 were executed. Therefore, Covered would state that for this module the line coverage percentage would be 75% (or 3 out of 4).

2.1.2 Recommendations

Recommendations

For a design to pass full coverage, it is recommended that the line coverage for all modules in a design receive 100% coverage. If a line of logic is not executed during simulation, the design has not been fully exercised. Line coverage is useful for determining holes in the test suite.

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