What is a CPU?
Look, there are people who think that the CPU is the processor found in the motherboard (the point). But there is also an opinion that it is the CPU casing and its contents including motherboard, memory, hard drives, power supply, cables and all the devices attached to it such as CDROM, Floppy drive, de el el. Once again I just took part in giving an alternative view on the CPU.
based on the knowledge that I have and once again not want to get stuck into the two opinions that have been mentioned before because it could be both true. It all depends on the understanding and belief in yourself, the best is your jury and of course others.
CPU stands for is the Central Processing Unit. CPU is responsible for performing all of the mathematical calculations required by the computer to function properly. Because the computer can not function without the CPU (which may also be referred to as the central processor or just the processor alone), it is not uncommon to hear people refer to the CPU as the "brains" of a computer.
CPU is processing the program instruction on micro computer called a micro-processor (processor mikor). This processor is a chip consisting of thousands to millions of IC (Integrated Circuit). Where IC is used to implement functions logika.CPU consists of two main parts:
1. Arithmetika unti Logic (ALU)
The main task of the ALU is to perform all arithmetic calculations (math), which occurs in accordance with the instructions of the program. ALU perform all arithmetic operations on the basis of the sum so that the electrical circuit used is called the Adder. Another task of the ALU is to make a decision of a logic operation in accordance with the instructions of the program. Logic operation involves comparison of two operands by using a certain logical operators, namely: equal (=), less than (<), or more than (>).
2. Control Unit (CU) = control unit
This unit is responsible for managing or controlling any existing equipment on the computer system. The control unit will be set when the input device to receive data and when data is processed and when displayed on the screen output.
This unit also interprets the instructions from computer programs, bringing data from input devices to main memory and retrieve data from main memory to be processed. If there are instructions for the calculation of arithmetic or logical comparisons. So this control unit will send instructions to the ALU.
Results of data processing is carried by the control unit to the main memory for storage and in time will be presented to the output device. Thus the task of the control unit are:
* Regulate and control the input output devices
* Taking instructions from main memory
* Retrieve data from main memory (if needed) to be processed
* Send instructions to the ALU when there is arithmetic or logical comparisons, and oversees the work of the ALU
* Saving results into the main memory
Besides, the CPU has a small storage device called the Registry. Register a small storage devices that have a high-speed access that is used to store data and instructions are being processed, while other data and instructions that are waiting their turn to be processed is stored in main memory.
Thus there are 3 kinds of memory used in computer systems, namely:
1. Register (used to store instructions and data being processed yangs
2. Main memory (used to store instructions and data to be processed and store data processing)
3. Secondary storage (used for storing programs and data permanently)
How does CPU work?
In order to do their work properly, the CPU must complete the four-step cycle. The first step in this cycle is to get an instruction from the memory of the software program. After taking the CPU instruction, the second step is to translate the instructions. By translating the instructions, the CPU can manage information from instruction in a way that allows the CPU to complete the next step, which is being executed.
During the execution of these steps, the CPU complete instructions. This can be achieved by following the information obtained during the steps of translation. After the CPU executes the instruction is completed, the final step in this cycle is to write-back results that occurred during the execution stages. CPU can write the results back to the internal register, or to the main memory of the computer.