A Novel Profile-Driven Technique for Simultaneous Power and Code-size Optimization of Microcoded IPs

摘要

Microcoded customized IPs have significantly better performance, yet larger code size, compared to similarly-sized instruction-based processors. Storing wide microcodes on-chip requires wide memory-blocks that occupy a large area and consume high leakage power. Therefore, addressing the code size of microcoded IPs is very important. In this paper, we introduce compression techniques that along with careful resolution of "don't care" values (denoted by X') in microcode can address the code size issue. We observed that X' values can be used for improving either dynamic power of IPs or their compression. However, achieving the efficiency of both is challenging. In this paper, we propose a profile-guided 'X'-resolution technique that can achieve both power and compression efficiency. Using our technique, the code size of microcoded IPs is reduced by 2.7 times, while saving 20% dynamic power, on average.