Can RF Help CMOS Processors? [Topics in Circuits for Communications]

Digital circuits implemented in CMOS technology have been the workhorses of high performance computer processors for more than a decade, following Moore´s law with exponentially increasing integration and performance. Driven by lower cost, increasing performance, and mixed-signal benefits, CMOS technology also has found increasing use in analog, and more recently, RF applications. Now, with transistor performance still improving, wires are becoming the limiting factor for speed and performance by imposing limits on communication bandwidth and latency between processing cores and memories, both off- and on-chip. Communication and circuit techniques, developed mainly for narrow band-wireless RF communication can help increase the wired communication speed in digital systems. This approach, dubbed RF Interconnect (RF-I), picks up speed for on-board and on-chip applications, changing the communication paradigm from the old parallel unidirectional time-shared bus to new transmission lines enabling reconfigurable communication using both frequency and code division multiple access techniques.