Electronically tuneable computer clocking system and method of electronically tuning distribution lines of a computer clocking system

摘要

A resonant clocking system is described which utilizes a feedback clock signal from the master clock node on a clocked chip and wherein the feedback clock signal is detected with a phase detector to determine the relevant phasing of the transmitted and the feedback received clock signals. An electronically controllable delay element is disposed within the transmission path of the clock signal on both the transmission leg and the return leg so that equal amounts of delay time may be added to the flight time in each direction. The delay may be electronically controlled to bring a "Transmitted Clock" pulse and a "Received Clock" pulse into phase. By insuring that the delay time for the entire transmission of the circuit by a particular clock pulse is an even number of cycle times, the master clock node on the clocked chip also may be controlled to be in phase with the "Transmitted Clock" pulse signal. This may be accomplished by initially calibrating the system at one-half of normal operating frequency and bringing "Transmitted Clock" pulse and "Received Clock" or feedback pulse into phase. Thereafter, upon returning to normal operating frequency, there always will be an even integral number of cycles of time delay between the transmission of the clock pulse by the oscillator and the receipt of that identical clock pulse by the phase detector; additionally, the pulse at the master clock mode will be in phase.