Towards a Unified Framework for Design of MEMS based VLSI Systems

Abstract

Current day VLSI systems have started seeing increasing percentages of multiple energy domain components being integrated into the mainstream. Energy domains such as mechanical, optical, fluidic etc. have become all pervasive into VLSI systems and such systems are being manufactured routinely. The framework required to design such an integrated system with diverse energy domains needs to be evolved as a part of conventional VLSI design methodology. This is because manufacturing and design of these integrated energy domains although based on semiconductor processing, is still very ad-hoc, with each device requiring its dedicated design tools and process integration. In this thesis three different approaches in different energy domains, have been pro-posed. These three domains include modelling & simulation, synthesis & compilation and formal verification. Three different scenarios have been considered and it is shown that these tasks can be co-performed along with conventional VLSI circuits and systems. In the first approach a micro-mechanical beam bending case is presented. A thermal heat ow causing the beam to bend through thermal stress is analyzed for change in capacitance under a single analysis and modelling framework. This involves a seamless analysis through thermal, mechanical and electrical energy domains. The second part of the thesis explores synthesis and compilation paradigms. The concept of a Gyro-compiler analogous to a memory compiler is proposed, which primarily generates soft IP models for various gyro topologies. The final part of this thesis deals in showcasing a working prototype of a formal verification framework for MEMS based hybrid systems. The MEMS verification domain today is largely limited to simulation based verification. Many techniques have been proposed for formal verification of hybrid systems. Some of these methods have been extended to demonstrate, how MEMS based hybrid systems can be formally verified through ex-tensions of conventional formal verification methods. An adaptive cruise control (ACC) system with a gyro based speed sensor has been analyzed and formally verified for various specifications of this system.