（2）Processing Unit

（2）Processing Unit
The heart of any computer system is the central processing unit(CPU),located inside the computer's main box or system unit.
A processor is composed of two functional units—a control unit and an arithmetic/logic unit-and a set of special workspaces called registers.
Figure 1-3 depicts its structure,in which the Internal CPU interconnection provides communication among the Control Unit,ALU,and Registers.
The control unit is the functional unit that the responsible for supervising the operation of the entire computer system.
The control unit fetches instructions form memory and determines their types of decodes them.It then breaks each instruction into a series of simple small steps or actions. By doing this,it controls the step-by-step operation of the entire computer system.
The arithmetic and logic unit(ALU) is the functional unit that provides the computer with logical and computational capabilities.Data are brought into the ALU by the control unit,and the ALU performs whatever arithmetic or logic operations are required to help carry out the instruction.
A register is a storage location inside the processor. Registers in the control unit are used to keep track of the overall status of the program that is running.Control unit registers store information such as the current instruction,the location of the next instruction to be executed,and the operands of the instruction. In the ALU,registers store data items that are addded,subtracted,multiplied, divided,and compared.Other registers store the results of arithmetic and logic operations.

（2）Processing UnitThe heart of any computer system is the central processing unit(CPU),located inside the computer's main box or system unit.
处理单元任何计算机系统的核心是中央处理单元(CPU)，位于计算机的主箱或系统单元内。
A processor is composed of two functional units—a control unit and an arithmetic/logic unit-and a set of special workspaces called registers.
处理器由两个功能单元-一个控制单元和一个算术/逻辑单元-以及一组称为寄存器的特殊工做区组成。
Figure 1-3 depicts its structure,in which the Internal CPU interconnection provides communication among the Control Unit,ALU,and Registers.
图1-3描述了其结构，其中内部CPU互连提供控制单元、ALU和寄存器之间的通讯。
The control unit is the functional unit that the responsible for supervising the operation of the entire computer system.
控制单元是负责监督整个计算机系统运行的功能单元。
The control unit fetches instructions form memory and determines their types of decodes them.
控制单元获取指令造成内存并肯定它们的解码类型。
It then breaks each instruction into a series of simple small steps or actions.
而后，它将每一个指令分解成一系列简单的小步骤或操做。
By doing this,it controls the step-by-step operation of the entire computer system.
经过这样作，它控制整个计算机系统的逐步操做。
The arithmetic and logic unit(ALU) is the functional unit that provides the computer with logical and computational capabilities.
算术逻辑单元(ALU)是为计算机提供逻辑和计算能力的功能单元。
Data are brought into the ALU by the control unit,and the ALU performs whatever arithmetic or logic operations are required to help carry out the instruction.
数据由控制单元带入ALU，ALU执行任何须要的算术或逻辑操做来帮助执行指令。
A register is a storage location inside the processor.
寄存器是处理器内部的存储位置。
Registers in the control unit are used to keep track of the overall status of the program that is running.
控制单元中的寄存器用于跟踪正在运行的程序的整体状态。
Control unit registers store information such as the current instruction,the location of the next instruction to be executed,and the operands of the instruction.
控制单元寄存器存储信息，如当前指令、下一条要执行的指令的位置和指令的操做数。
In the ALU,registers store data items that are addded,subtracted,multiplied, divided,and compared.
在ALU中，寄存器存储被加、减、乘、除和比较的数据项。
Other registers store the results of arithmetic and logic operations.
其余寄存器存储算术运算和逻辑运算的结果。

（2） 处理器
任何计算机的核心都是中央处理器（CPU），放在计算机主机箱或系统单元中。
处理器有两个功能部件（控制器部件和算术逻辑部件）与一组称为寄存器的特殊工做区组成。
图1-3 描述了处理器的结构。其中，CPU的内部互连机构提供了控制部件、算术逻辑部件和寄存器之间的通讯。
控制部件从存储器中取出指令，并肯定这些指令的类型或对其进行译码。而后将每条指令部分分解成一系列简单的小步骤或动做。这样，它就控制了整个计算机系统的步进操做。
算术逻辑部件（ALU）是为计算机提供逻辑及计算功能的部件。控制部件将数据送入蒜素逻辑部件，而后又算术逻辑部件完成指令所要求的某些算术或逻辑运算。
寄存器是处理器内的存储单元。控制部件中的寄存器用来跟踪正在运行的程序的整体状态。控制器寄存器存储器诸如当前指令、下一条将要执行的指令地址以及该指令的操做数等信息。在算术逻辑部件中，寄存器存放要进行加、减、乘、除以及要比较的数据项。二其余寄存器则存放算术和逻辑运算的结果。