Sequential analysis driven reset optimization to improve power, area and routability

Resets are required in the design to initialize the hardware for system operation and to force it into a known state for simulation or to recover from an error. Given the increasing design complexity and time-to-market pressures, figuring out the registers which do not require resets is extremely challenging. In this paper, we present a novel algorithm which uses observability based sequential analysis to identify the registers in design which do not require resets. With the proposed algorithm, we have seen that in some cases 70% registers in the design can have redundant resets. Further, with removal of the redundant resets on registers up to 22% sequential power savings and up to 3% area reduction post-layout can be obtained.