Exploiting Variable Cycle Transmission for Energy-Efficient On-Chip Interconnect Design

As on-chip interconnect in deep-submicron designs contribute to the system-wide power consumption, minimization of interconnect power consumption has become one of the important design issues in deep-submicron technologies. As transition activity mainly determines the interconnect power consumption, several bus encoding techniques have been proposed to minimize the activity. Unlike the existing low-power or energy-efficient bus encoding techniques, in this paper, we propose a scheme which exploits both dynamic voltage scaling and variable cycle transmission mechanisms for minimizing on-chip interconnect energy consumption. We transmit data using variable cycle transmission method and, based on the delay savings achieved through variable cycle transmission method at regular intervals, scale the voltage and frequency to obtain significant energy savings. Using our technique for a 5 mm interconnect wire we achieved energy savings of 30% and 45% over the base case in the address bus and data bus, respectively. Our technique also reduces the energy-delay-product by 34% and 52% for address bus and data bus, respectively.