As we indicated in Chapter 6, the term state machine, also called finite state machine or algorithmic state machine (ASM) is the same as sequential system. A tool that is a cross between a state diagram and a flow chart is theASM diagram (sometimes referred to as anASM chart). We will first describe the basic elements and compare its structure to that of a state diagram. Then, we will apply this tool to a controller for a small system of registers (the place where this tool is most useful).