An efficient critical path tracing algorithm for sequential circuits

Several timing verification algorithms for combinational circuits have been proposed in the last few years. However, similar algorithms do not exist for sequential circuits. Existing algorithms have difficulty in performing timing verification even for combinational circuits due to the excessive computation time and memory requirement for identifying the critical path. This paper presents a critical path analysis algorithm for sequential circuits. The algorithm can be used to identify the critical path of a sequential circuit while considering exact operation of the circuit without assuming the use of scan techniques. The input sequence which sensitizes the critical path is determined as well.