55,518 research outputs found
RTL2RTL Formal Equivalence: Boosting the Design Confidence
Increasing design complexity driven by feature and performance requirements
and the Time to Market (TTM) constraints force a faster design and validation
closure. This in turn enforces novel ways of identifying and debugging
behavioral inconsistencies early in the design cycle. Addition of incremental
features and timing fixes may alter the legacy design behavior and would
inadvertently result in undesirable bugs. The most common method of verifying
the correctness of the changed design is to run a dynamic regression test suite
before and after the intended changes and compare the results, a method which
is not exhaustive. Modern Formal Verification (FV) techniques involving new
methods of proving Sequential Hardware Equivalence enabled a new set of
solutions for the given problem, with complete coverage guarantee. Formal
Equivalence can be applied for proving functional integrity after design
changes resulting from a wide variety of reasons, ranging from simple pipeline
optimizations to complex logic redistributions. We present here our experience
of successfully applying the RTL to RTL (RTL2RTL) Formal Verification across a
wide spectrum of problems on a Graphics design. The RTL2RTL FV enabled checking
the design sanity in a very short time, thus enabling faster and safer design
churn. The techniques presented in this paper are applicable to any complex
hardware design.Comment: In Proceedings FSFMA 2014, arXiv:1407.195
Formal Verification of Fault Tolerant NoC-based Architecture
International audienceApproaches to design fault tolerant Network-on-Chip (NoC) for System-on-Chip(SoC)-based reconfigurable Field-Programmable Gate Array (FPGA) technology are challenges on the conceptualisation of the Multiprocessor System-on-Chip (MPSoC) design. For this purpose, the use of rigorous formal approaches, based on incremental design and proof theory, has become an essential step in a validation architecture. The Event-B formal method is a promising formal approach that can be used to develop, model and prove accurately the domain of SoCs and MPSoCs. This paper gives a formal verification of a NoC architecture, using the Event-B methodology. The formalisation process is based on an incremental and validated correct-by-construction development of the NoC architecture
Incremental bounded model checking for embedded software
Program analysis is on the brink of mainstream usage in embedded systems development. Formal verification of behavioural requirements, finding runtime errors and test case generation are some of the most common applications of automated verification tools based on bounded model checking (BMC). Existing industrial tools for embedded software use an off-the-shelf bounded model checker and apply it iteratively to verify the program with an increasing number of unwindings. This approach unnecessarily wastes time repeating work that has already been done and fails to exploit the power of incremental SAT solving. This article reports on the extension of the software model checker CBMC to support incremental BMC and its successful integration with the industrial embedded software verification tool BTC EMBEDDED TESTER. We present an extensive evaluation over large industrial embedded programs, mainly from the automotive industry. We show that incremental BMC cuts runtimes by one order of magnitude in comparison to the standard non-incremental approach, enabling the application of formal verification to large and complex embedded software. We furthermore report promising results on analysing programs with arbitrary loop structure using incremental BMC, demonstrating its applicability and potential to verify general software beyond the embedded domain
Hardware/Software Co-verification Using Path-based Symbolic Execution
Conventional tools for formal hardware/software co-verification use
bounded model checking techniques to construct a single monolithic propositional formula. Formulas generated in this way are extremely complex and contain a great deal of irrelevant logic, hence
are difficult to solve even by the state-of-the-art Satisfiability (SAT)
solvers. In a typical hardware/software co-design the firmware only
exercises a fraction of the hardware state-space, and we can use this
observation to generate simpler and more concise formulas. In this
paper, we present a novel verification algorithm for hardware/software co-designs that identify partitions of the firmware and the hardware logic pertaining to the feasible execution paths by means of
path-based symbolic simulation with custom path-pruning, propertyguided slicing and incremental SAT solving. We have implemented
this approach in our tool COVERIF. We have experimentally compared COVERIF with HW-CBMC, a monolithic BMC based co-verification
tool, and observed an average speed-up of 5× over HW-CBMC for
proving safety properties as well as detecting critical co-design bugs
in an open-source Universal Asynchronous Receiver Transmitter
design and a large SoC design
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