make & view coverage reports

1. To monitor coverage, include COVERAGE=VCS option during simulation.

For instance:

    $ make TEST_ROM=median_rom.v TRACE_ROM=median_rom.tr.v COVERAGE=VCS bp_single_trace_demo.run.v
2. To generate coverage reports, run the following command:
    $ make COVERAGE=VCS urg

This command will generate reports in both html and txt format. You can view reports in bp_top/syn/coverage_reports folder.

3. Editing signal and module coverage of Coverage reports

In file coverage.hier, I specify signals excluded from coveage report.