Models of I/O characteristics are used to accurately
simulate the signal behavior on a printed circuit
board (PCB). Most designers are familiar with SPICE
models, but a given manufacturer’s SPICE models
contain information that is considered to be proprietary. Therefore, simpler models are devised that extract the SPICE parameters and present them to the user in such a way that the proprietary information is protected. One such form is the I/O buffer information specification (IBIS) format. This white paper describes some of the features of the IBIS format as well as how to use them.