Signal Integrity(SI) is one of the most important problem in the area of high speed digital design.Nearly all of the PCBs have some SI problems recently.The electrical wire of PCB is a kind of transmission line with no resistive losses.(According) to the theory of transmission line,people may analyze and research the signal characteristics in high speed PCB,and then find the methods to solve the problem of SI problems.This theory explains and compares two methods: source termination and terminal termination...