Exploiting program redundancy to improve performance, cost and power consumption in embedded systems

During the last 15 years embedded systems have grown rapidly in complexity and performance to a point where they now rival the design challenges of desktop systems. Embedded systems are now targets for contradictory requirements: they are expected to occupy a small amount of physical space (e.g., low package count), be inexpensive, consume low power and be highly reliable. Regardless of the decades of intensive research and development, there are still areas that can promise significant benefits if further researched. One such area is the quality of the data which embedded system operates upon. This includes both code and data segments of an embedded system application. This work presents a unified, compiler-driven approach to solving the redundancy problem. It attempts to increase the quality of the data stream that embedded systems are operating upon while preserving the original functionality. The code size reduction is achieved by Huffman compressing or tailor encoding the ISA of the original program. The data segment size reduction is accomplished by modified Discrete Dynamic Huffman encoding. This work is the first such study that also details the design of instruction fetch mechanisms for the proposed compression schemes.