State Machine's Thought
State (current status and next state) and status conversion, is the basic concept of the state machine. For example, now designed a simple ordinary telephone control IC, then the first thing is to consider whether this Device has several states? According to our common sense, you can know if the phone is quietly lying there. It is not dry. What is it? If the user is taken, the keypad controller is ready to detect the keyboard, this is a state? (Of course, it can also be separated from the hang-up, frame spring, normal dial, etc., but also to handle separately). If this is called this time? Then you have to do a response. If you type it normally, send the dial to the send port, then wait for the switch to send the corresponding signaling, such as the bell tone, the other party, the other party hangs, that is, the exchange of signaling is correspondingly . Then use the status, you can describe: (huh, simple expression, only for the "status" concept, detailed status can check the telecom handbook) Et. IDLE =====> Scankey === => Process ====> iDLE; (complex state can also be sub-state) The called IDLE ======> Ring =====> Process ====> idle;
The drive signal always says that the use of the form can be expressed as: current state ==================================================================================================================================================================================================================================================
