Relation Coverage: A New Paradigm for Hardware/Software Testing

While the Hardware (HW) domain and the Software (SW) domain use the concept of coverage to measure the thoroughness of tests, there isn't an established common metric that applies to both worlds. In this paper we make two major contributions: First, leveraging the abstraction of Virtual Prototypes (VPs), we unify HW/SW coverage by viewing the HW/SW system as a single model. This enables the measurement of structural HW/SW metrics like line, function, and branch coverage via a novel non-intrusive approach, where neither the VP (representing the HW) nor the SW requires any modification. Second, based on the unified HW/SW coverage, we introduce relation coverage. The innovation is that the user can define a relation between the frequency of executing lines in the SW and the execution count of corresponding lines of the HW model. This relation expresses expected behavior to be covered during testing. As a case study, we consider HW/SW testing of a Gyroscope sensor controlled by SW running on a RISC-V VP.