An adaptive algorithm for computing the initial states of retimed circuits

Retiming is an important technique to minimize the delay and/or area by relocating registers in sequential circuits. In this paper, we formulate a new problem for initial state computation for a set of retimed circuits having the same corresponding finite state machine, and propose a new adaptive algorithm to solve it. The retimed circuit discussed in this paper can be any circuit with forward and/or backward retiming or even with circuit replication. The proposed new adaptive algorithm based on homing sequence technique can effectively compute an equivalent state of the retimed circuit whenever the initial state of the original circuit can be reached from some final states corresponding to some homing sequences of the corresponding finite state machine. It is also applicable to sequential circuits with partial initial state assignments by allowing that some values of registers are not specified.