51 MCU Series Serial 10-Serial Communication

     Today I will introduce computer communication. Computer communication refers to the information exchange between a computer and an external device or between two computers. There are two types of computer communication: parallel communication and serial communication. Parallel communication usually uses multiple data lines to transmit each bit of a data byte at the same time, as shown below:

 

                              

      In multi-microcomputer systems and modern measurement and control systems, serial communication is often used for information exchange.

 

                             

 

       Serial communication is the process of dividing data bytes into bits and transmitting them one by one on a transmission line. Serial communication includes synchronous communication and asynchronous communication. Asynchronous communication means that the sending and receiving devices of the communication use their own clocks to control the sending and receiving process of data. In order to coordinate the sending and receiving of both parties, the clocks of the sending and receiving devices are required to be as consistent as possible. Asynchronous communication is transmitted in units of characters (frames), as shown in the following figure:

 

                               

     In synchronous communication, it is necessary to establish direct control of the sender's clock over the receiver's clock so that both parties can achieve complete synchronization.

 

                   

                         External synchronization and                                                               self-synchronization

    

     Next, let's talk about the transmission direction of serial communication, which includes 3 types:
     1. Simplex: Simplex means that data can only be transmitted in one direction and cannot be transmitted in the reverse direction.
     2. Half-duplex: Half-duplex means that data can be transmitted in two directions, but it needs to be done in time.
     3. Full-duplex: Full-duplex means that data can be transmitted in both directions at the same time.

 

     Due to time constraints, I will just say this much for now. To be continued.