Research

My research work has been mainly focused on the design and implementation of next-generation, customizable application-specific embedded processors and systems. The objective of this work is the definition of novel embedded processor architectures and embedded systems capable of incorporating and utilizing application knowledge so as to achieve significant power and performance improvements, as well as predictable execution times. The basic approach is to identify global and local application properties during compile/link time and/or through profiling and exploit them dynamically during program execution by the processor. The application properties are utilized by a microarchitecturally reprogrammable hardware, thus maintaining the flexibility and the consequent low design and verification cost as no new silicon spins or VLSI design reiterations are required in the face of new application targets or software modifications.

The customization policy consists of the synthesis of reprogrammable hardware, to be used as a customization vehicle for various micro-architectural features, such as data/instruction caches, branch resolution logic, on/off-chip memory communication, etc. The reprogrammable logic includes tables of programmable registers, a reconfigurable data path and memory cells. This logic aims to enhance the microprocessor architecture with application-specific properties. The proposed customization logic is reprogrammable in the sense of loading a set of registers or tables with specific values for controlling simple data paths or for defining certain special events for the particular application.

The overall objective of my work is the identification of a comprehensive set of customization methodologies for achieving low power, high performance, and predictable execution times in the next generation embeeded systems and processors. The reprogrammable hardware support, developed for accomodating and exploiting the application knowledge, defines a unified embedded architecture. This architecture is capable of recustomization in a post manufacturing fashion, thus achieving all the flexibility benefits of general purpose systems, while attaining significant power and performance improvements through the utilization of application-specific information. For more in-depth technical information regarding the various low-power and performance boosting customization techniques that we have developed, please refer to the technical publications page.