The serial interface is a pervasive component within many electronic products and will be familiar to users of personal computers and modern electronic devices. Over the last twenty years, the serial interface or link has developed from a specialist electronic subsystem for computer and telecommunication systems to an essential building block for modern electronic products ranging from disk storage devices to home entertainment consoles. The high speed serial interface (HSS!) offers fast data transfer at relatively low cost and is now an semiconductor vendors supplying chips to original equipment manufacturers.