Computer Logical Organization 简明教程

Boolean Algebra

布尔代数用于分析和简化数字(逻辑)电路。它只使用二进制数,即 0 和 1。它也被称为 Binary Algebralogical Algebra 。布尔代数是由 George Boole 于 1854 年发明的。

Boolean Algebra is used to analyze and simplify the digital (logic) circuits. It uses only the binary numbers i.e. 0 and 1. It is also called as Binary Algebra or logical Algebra. Boolean algebra was invented by George Boole in 1854.

Rule in Boolean Algebra

以下是布尔代数中使用的重要规则。

Following are the important rules used in Boolean algebra.

  1. Variable used can have only two values. Binary 1 for HIGH and Binary 0 for LOW.

  2. Complement of a variable is represented by an overbar (-). Thus, complement of variable B is represented as . Thus if B = 0 then = 1 and B = 1 then = 0.

  3. ORing of the variables is represented by a plus (+) sign between them. For example ORing of A, B, C is represented as A + B + C.

  4. Logical ANDing of the two or more variable is represented by writing a dot between them such as A.B.C. Sometime the dot may be omitted like ABC.

Boolean Laws

有六种类型的布尔定律。

There are six types of Boolean Laws.

Commutative law

满足以下表达式的任何二进制运算都称为交换运算。

Any binary operation which satisfies the following expression is referred to as commutative operation.

commutative

交换定律指出,更改变量的顺序对逻辑电路的输出没有任何影响。

Commutative law states that changing the sequence of the variables does not have any effect on the output of a logic circuit.

Associative law

此定律指出,执行逻辑运算的顺序无关紧要,因为它们的效果相同。

This law states that the order in which the logic operations are performed is irrelevant as their effect is the same.

associative

Distributive law

分配律规定了以下条件。

Distributive law states the following condition.

distributive

AND law

这些律使用 AND 运算。因此它们被称为 AND 律。

These laws use the AND operation. Therefore they are called as AND laws.

and

OR law

这些律使用 OR 运算。因此它们被称为 OR 律。

These laws use the OR operation. Therefore they are called as OR laws.

or

INVERSION law

此律使用 NOT 运算。反演律规定变量的双重反演产生原始变量自身。

This law uses the NOT operation. The inversion law states that double inversion of a variable results in the original variable itself.

not

Important Boolean Theorems

以下是一些重要的布尔定理:

Following are few important boolean Theorems.

Boolean function/theorems

Description

Boolean Functions

Boolean Functions and Expressions, K-Map and NAND Gates realization

De Morgan’s Theorems

De Morgan’s Theorem 1 and Theorem 2