An approach for reference model implementation by predicting all possible output of design

Lirong Qiu

COMPUTER MODELLING & NEW TECHNOLOGIES 2014 18(5) 131-137

School of Information Engineering, Minzu University of China, Beijing, China

In verification system, it is preferable to build reference model at transaction level which does not produce the output as the same latency as the design itself. But due to the lack of accurately modelling design’s behaviour, there are some scenarios that design’s output is different with reference model’s output due to the different processing delay of stimulus. Scoreboard can get lots of comparison failure when it tries to do comparison between the output of reference model and design under such scenarios. In this case, neither reference nor design is wrong from functionality, but output comparison failure will mix up with the true design issue and bring trouble to the automatic check on design’s behaviour. Cycle based reference model does not have such problem. But it usually takes great effort to implement cycle based reference models and maintain them. This paper provides its study on implementation style of reference model. By predicting all possible output of design, this paper presents a method for reference model to handle such stimulus competition scenarios at the transaction level. The paper also discusses the reference model’s reaction effect on generator, which helps the test hit design’s corner case.