an algebra for logic strength simulation
To simulate tri-state logic in a non-pessimistic way, a six valued algebra is shown to be necessary. This is then extended to quin-state logic (strong 0, strong 1, weak 0, weak 1, high impedance) and a fifteen valued algebra. The improved accuracy is as important for fault simulation as for design verification. The requirements for non-pessimistic test generation algebras for tri-state and quin-state logic are also discussed. Pessimism in test generation increases the search space and hence the run time.
algebra logic simulation accuracy fault design verification requirements test generation search space timing