Abstract: A complete procedure for verifying register-transfer logic against its scheduled behavior in a high-level synthesis environment is provided. A new method that is both complete and practical for verification is provided. Hardware verification is known to be a hard problem and the proposed verification technique leverages off the fact that high-level synthesis--performed manually or by means of high-level synthesis software--proceeds from the algorithmic description of the design to structural RTL through a sequence of very well defined steps, each limited in its scope. Equivalence checking task is partitioned into two simpler subtasks, verifying the validity of register sharing, and verifying correct synthesis of the RYL interconnect and control. While state space traversal is unavoidable for verifying validity of the register sharing, irrelevant portions of the design are automatically abstracted out, significantly simplifying the task that must be performed by a back-end model checker.

Abstract: A Boolean SAT solver uses reconfigurable hardware to solve a specific input problem. Each of the plurality of ordered variables has a corresponding one of a plurality of state machines. Each state machine has an implication circuit for its respective variable, and operates in parallel according to an identical state machine. One state machine implements the Davis-Putnam method in hardware and provides improved performance over software by virtue of the parallel checking of direct and transitive implications. Another state machine implements a novel non-chronological backtracking method that takes advantage of the parallel implication checking and avoids the need to maintain or to traverse a GRASP type implication graph in the event of backtracking. The novel non-chronological backtracking provides for setting a blocking variable as a leaf variable and for changing only the value of the leaf variable, but possibly changing both the value and identity of a backtracking variable.

Abstract: A breadth-first manipulation of reduced, ordered binary decision diagram representation of a logic circuit eliminates page access time bottlenecks encountered when obtaining nodes from secondary memory to primary memory by providing an orderly page access arrangement. The pointer to a node is the address at which the node is located in memory, from which address the memory block at which the node is located is determined. A look-up table is used to convert the memory block information into a variable index indicative of the level at which the node is located. The queue of ITE (if.sub.-- then.sub.-- else) requests is maintained on a per level basis.

Abstract: A computer-implemented process for doing timing analysis of a VLSI sequential circuit that includes false paths. It includes the steps of transforming the circuit into a functionally equivalent .delta. path disjoint circuit for a given delay value and propagating all inverters to primary inputs of the circuit and performing a multifault test on all primary input fanouts of a particular length consisting solely either of all zoroes or of all ones.

Abstract: A methodology for the redesign of sequential VLSI circuits to increase the circuit speed involves cascading the circuit over a plurality of time frames without the memory elements, identifying any long false paths in the cascaded circuit, reconfiguring the original circuit to eliminate the false paths while providing fanout to preserve functionality, and retiming the reconfigured circuit to reduce circuit delay.