An automated tool for optimizing margins, using distributed references, in a high-speed signaling environment.

摘要

Ever increasing time-to-market pressures make systemic high-speed design approaches a must, even in early design stages. However, such approaches are difficult due to lack of integrated toolsets capable of meeting both I/O and interconnect needs. Additionally, electronic design automation tools begin to have theoretical and practical limits, mainly due to approximation methods used to solve Maxwell's equations.; Gigahertz-speed data transfer rates also translate into tight integration of silicon and interconnects. This increased interdependency makes the traditional approach---designing systems components in isolation---obsolete.; To compensate for higher interconnect losses, additional capabilities, such as filtering, have to be implemented in silicon. Due to system dependencies such capabilities can only be characterized using distributed loads closely matched to operational conditions. Consequentially, realistic (idealized) distributed loads have to be used as a design reference, replacing traditional lumped elements in I/O characterization. Such loads can also be used to increase early design integration and to bridge the existing tool gap in silicon and interconnect design capabilities.; Examples of driver and receiver optimizations from a systemic point of view based on readouts from a software enhancement, the "Eye Diagram Analyzer" (EDA) are described. The software enhancement is written in C-code and offers the advantage of providing an accurate numerical analysis and interpretation of Eye Diagram data from time domain simulations or measurements, which can be used for real-time (statistical) data analysis. The software has been written as a series of functions making it attachable through function calls to a variety of traditional high speed design tools.; As results a comprehensive methodology to characterize digital transmission paths has been achieved. The methodology has the advantage that is tool-independent, simple, and accurate up to users needs. It can be used to develop, using mathematical function, realistic transmission lines based on frequency domain measurements. It can also be used to characterize I/O enhancements such as equalization, based on real time system margining as well as incorporate I/O and interconnects into a complete system.