Sophomore, I am studying the basics of digital circuit and system design, which can be roughly divided into these parts. In the first part, the understanding and transformation of logical values are generally a lot of 010001011,simplifying and looking for rules. The second part, combinatorial logic, introduces many chips, and you need to combine these chips to achieve the desired effect. The simplest input is 0 and the output is 1. The third part, flip-flop, tells you that the circuit has delay. You can use the delay, sometimes you need to reduce the delay, and add several chips through the delay of the circuit, such as flip-flop, register and counter. The fourth part is digital-analog exchange, which teaches you how to convert continuous analog signals into discontinuous digital signals (0 1) and vice versa. In the fifth part, I'm studying. I've talked about the internal structure of the basic gate circuit, NMOS and CMOS, but I don't know much about it for the time being. The sixth part is synthesis.