Specman Based Verification Methodology for ... - CiteSeerX

‣ Checkers:This unit performs data and temporal (timing) checks which are explained below indetail.• Data Check:To perform data checks the memory output needs to be compared with expectedoutput. The expected output is obtained using scoreboard technique.Scoreboarding is a common verification technique and not e-specific. Here wehave built a reference memory which behaves exactly as per the specification.Any operation performed on the memory under test, is performed on the referencememory also and the output of this reference memory is compared with thememory under test outputREFERNCEMEMORYoutputSeqDriverBFMCompareinputMEMORYUNDER TESToutputFig 4: Reference MemoryTo build a reference memory we need to allocate a static array, but this willconsume huge system memory. To avoid this we are using a dynamically createdkeyed list. When a write operation is performed on the memory under test, theaddress accessed is added to keyed list. When a particular address location iscorrupted due to, say a timing violation then that address location is removedfrom the list.• Temporal Check:These checks involve path delay checks. In the case of memory there are accesstime checks and handshake signal timing checks. To perform these checks thesame timing information which is present in the memory under test, is provided tothe eVC. The monitor is asked to emit an event when there is a change in any ofthe signals involved in these paths. The timings of these events are noted and thencompared with the expected timings.7