Clock Technology: The Next Frontier

Abstract

Clocking of electrical circuit is a crucial issue since clock signal is used to establish the flow-of-time inside electronic world. Before, during and after the Moore's law, flow-of-time is an eternal issue. Alongside processor, memory/storage and analog/ RF technologies, IC clocking could be regarded as the 4th major IC design technology. In the past several decades, clock is mostly used in the form of fixed-frequency with high frequency stability. For future system, however, this type of clock signal is not sufficient because its usage environment is not expected to be stationary but dynamic. To meet this challenge, innovation in IC clocking is required. This paper first discusses the difficulties in creating flow-of-time; then the two long-lasting problems in clock generation are identified, and then new challenges in the design of future system are summarized. Afterwards, the Time-Average-Frequency based flexible clock generator is introduced and its potential to confront these challenges is addressed. Several major issues in modern design are discussed. The paper concludes with a vision that, for electronic system to improve its information processing efficiency to next level, clock technology is the next frontier to be explored.