Computer Processor Elements and Components
Computer processor is the main part of the computer because it is responsible for all the operations done through the computer. In order to work, some components must exist inside the CPU chip. Here is an overview of such components.
The processor is mainly the brain of the computer because it controls all the processes done through the computer from typing to transferring data to remote computers. Inside the processor there are some basic elements the work together to make the processor functional. These elements are as follow:
1. Arithmetic Logic Unit (ALU): This is the main block in the processor and the most important. The ALU is responsible for performing all the computations needed through the processor. When the user,
for example, enters a numbers to add, this unit makes the computation and outputs the result to the output devices. All the arithmetic operations such as adding, subtraction, multiplying, or division is performed using this unit. Also the logical operations such as ANDing, ORing are also done using this unit. The unit accepts the data, then performs the operations and then output the results to other units inside the processor.
2. Registers: This is another type of devices existed inside the processor. The registers are responsible for saving temporarily the results obtained from other devices such as ALU. One can think of registers as a short term memory as it save some values for a short period of time and then takes other values as needed by the computing devices. For example when you add two numbers if you take the first two numbers and add them and see the result is higher than ten you save the remaining in your head and this saving corresponds to putting the number remained in a register.
3. Busses. This is the third type of components existed inside the processor. The main use of the bus is to transfer any type of data between components inside the processor or among the processor and the remaining devices inside the computer such as motherboard. The buses are divided into three main subtypes:
A. data bus: this type is used to transfer the data bytes between elements inside the processor. For example when the ALU outputs the result it may transfer it to registers by the data bus. It is named so because it is responsible to transfer only data bytes.
B. Address bus: this type of buses is used to fetch certain data from memory based on the number on the address bus. For example if the address bus has a binary value of 1101. Then it will fetch the value in memory in that address. Thus the address bus tells the processing units where to find the data in memory or where to put the computed data in memory.
C. Control bus: this type of buses is used to transfer control signals between elements of the processor. For example, when an instruction is decoded that it has addition operation, it will inform the ALU that the operation is addition by putting certain value on the control bus. When the Processor decodes this value it will understand that the operation is addition based on the value on the address bus.
4. Decoders: this type of devices is used to tell the processor what must be done based on the instructions in the memory written by users. So if ,for example, some bytes are found in the memory that corresponds to an addition instruction the decoder will read them and knows that it is addition based on the bytes contained then it will activate the control lines to inform the processor that it is an addition. Thus the processor is considered an interface between the memory and the processor