A Tools Flow for Extended Burst-Mode State Machines Design with Enhanced Robustness

Due to the increasing demand for mobile devices and CMOS-UDSM (Ultra Deep Sub-Micron) technology, the search for ultra-low-power projects is becoming a priority. One technique that allows a substantial reduction of circuits consumed power is the sub-threshold voltage operation, but it leads to some drawbacks. The Speed Independent asynchronous circuits show an interesting solution to operate at sub-threshold voltage because they satisfy the unbounded delay gate model. However, there is a limitation with UDSM technology because the wires have zero delays. In this paper, we propose an architecture and approach that synthesizes asynchronous finite state machines (AFSM) with enhanced robustness. They are described by the extended burst-mode (XBM) specification. The resulting XBM_AFSMs are flexible QDI (Quasi Delay Insensitive), so they can operate within sub-threshold voltage and in UDSM technology because they interact with the environment in flexible weak-indication mode. The approach is presented through the case study, and the XBM_AFSMs synthesized show a good optimization when compared to XBM_AFSMs from the literature.