A Zero Sum Signaling Method for High Speed, Dense Parallel Bus Communications

TL;DR

This paper introduces a zero sum signaling technique for high-speed, dense parallel bus communications that reduces physical channel count and mitigates simultaneous switching noise using coding strategies, validated through simulation.

Contribution

It presents a novel zero sum signaling method that enables single-ended buffers to reduce physical channels and mitigate SSN in high-speed digital interconnects, supported by simulation analysis.

Findings

Zero sum signaling effectively mitigates SSN in high-speed buses.

The method reduces the number of physical channels by nearly half.

Simulation results show comparable performance to traditional methods.

Abstract

Complex digital systems such as high performance computers (HPCs) make extensive use of high-speed electrical interconnects, in routing signals among processing elements, or between processing elements and memory. Despite increases in serializer/deserializer (SerDes) and memory interface speeds, there is demand for higher bandwidth busses in constrained physical spaces which still mitigate simultaneous switching noise (SSN). The concept of zero sum signaling utilizes coding across a data bus to allow the use of single-ended buffers while still mitigating SSN, thereby reducing the number of physical channels (e.g. circuit board traces) by nearly a factor of two when compared with traditional differential signaling. Through simulation and analysis of practical (non-ideal) data bus and power delivery network architectures, we demonstrate the feasibility of zero sum signaling and compare performance with that of traditional (single-ended and differential) methods.