LSI Verification Method Requiring No Extra Hardware
Original Publication Date: 1978-Feb-01
Included in the Prior Art Database: 2005-Feb-20
Verification of the correctness of computer designs is a mandatory part of their design and fabrication, Large-scale integration (LSI) makes engineering changes prohibitive in cost and time. Verification of design A is usually defined in terms of proof of equivalence with some other "standard" design B. When the designs are acyclic, the algorithm VERIFY  determines their equivalence or produces a counter-example (nonequivalence). For cyclic designs, eliciting in general sequential behavior, because of indeterminate behavior (races, hazards), it does not appear possible to develop a similar algorithm . Schemes for design have been devised which render the cyclic case equivalently acyclic for test-and-verification purposes. It was used in IBM System/ 360 with SCAN. Density increase and pin scarcity made SCAN obsolete.