Javed S. Barkatullah

Enhancing microprocessor immunity to power supply noise with clock/data compensation

This paper demonstrates an alternative to the conventional wisdom that microprocessors require a flat impedance spectrum across a broad range of frequencies in order to deliver maximum operating frequency. Delivering this impedance requires large amounts of on-die capacitance. We show through extensive analysis techniques that proper co-design of the clock and power distribution networks can relax this requirement, saving the area and leakage power needed for on-die decoupling. Measurements made on 130- and 180-nm processors validate the approach.

A design for digital, dynamic clock deskew

Unintentional clock skews between clock domains represent an increasing and costly overhead in high-performance VLSI chips. We describe a novel yet easy-to-implement design that reduces skew between local clock domains dynamically or statically by sensing clock-delay differences and then tuning the clock of each domain relative to its neighbors. Lowering local clock skew is accomplished without compromising worst-case global skew.