Optimal code layout for reducing energy consumption in embedded systems

Most of the microprocessor spends majority of its time waiting for the data to be transferred from slow memory devices connected to it, resulting in Memory wall problem. The main aim of this paper is to reduce memory wall problem by increasing not only processor speed but also the memory speed. This can be achieved by placing efficient and small memory near the processor so that energy efficiency of the system can be improved. Such memory is called Scratch Pad memory (SPM). Scratch pad memory (SPM) and cache memory plays a vital role in improving the efficiency of the system. Repositioning of code in on-chip and off-chip memory increases the efficient of the utilization of multiprocessing embedded system. Optimal code layout design is developed to place the code in memory for preventing the cache conflicts and misses. Many researchers discussed about the usage of SPM and cache memory to improve the efficiency of the system but combining the both is not done. In this work both SPM and cache memory is combined with the proposed Meta heuristics technique. Meta heuristic model is the proposed model in which along with the SPM, Cache code layout is developed to place the code in it, resulting better performance compared with the other two models namely ILP model and Heuristic model. It is found that the two stage meta-heuristic model yield more efficiency and consume less energy than other two models.