说明：  4bit ALU（运算逻辑单元）的设计 给出了此次设计alu的输入输出结构及相应的位数。其中C0是一位的进位输入，A和B分别是4位的数据输入，S0、S1、M分别为一位的功能选择输入信号；Cout是一位的进位输出，F是4为的运算结果输出。
(4bit ALU (arithmetic logic unit) design is given in the design of alu input and output structure and the corresponding median. C0 which is a binary input of, A and B are four data entry, S0, S1, M, respectively, as a function of choice of the input signal Cout of a binary output, F is 4 for computing the results of output.)