August 14, 2012 -- The concept of X, X corruption, and X propagation has been intriguing to many design engineers. Relating these terms to simulations and translating the impact of the same into behavior on silicon is difficult. This article focuses on giving an idea about these terms, reasons for the occurrence of X, the impacts it causes and some best practices to follow to avoid any undesirable effects. It aims to raise awareness of X issues in different phases of design flow and establish a basic understanding of the artifact of X in reader's mind with the help of examples.
By Deepak Mahajan, Aniruddha Gupta, Deepak Kumar Behera, and Narender Kaushik. (The authors are all with Freescale Semiconductor, Inc.)
This brief introduction has been excerpted from the original copyrighted article.