软硬件系统编程PPT (14).pdf

基本逻辑运算和逻辑门 Basic Logic Operation and Logic Gate I. LOGIC  Logic  A law that shows the cause and effect of things  The realization of logic is manifested by proposition and reasoning  Proposition  A statement that is either true or false  Reasoning  A thinking process that deduces conclusion from premise  Premise is a known proposition, and conclusion is a proposition deduced by reasoning 2 Logic Proposition Example: 2+3=5 true 3 is an even number false Are there classes tomorrow morning? Not a proposition 3 is not an even number. Not (negation) John has learned both English and German. And (simultaneity) From Xi’an to Beijing, people can go through Zhengzhou or Taiyuan. Or 3 Logic Proposition  Compound propositions can be constituted from simple propositions through the operation of “connectives”.  Proposition is the basic representation of logic, therefore, “connectives” represents logical operation  not NOT operation  and AND operation  or OR operation 4 Logic Proposition  The truth and false of a proposition can correspond to  In physic  the opening and closing of a switch, or the high and low level of electrical level.  In math  1 and 0 in binary system Modern computer is made up of various logic devices, and its mathematical foundation is logic algebr