CPU ( Central Processing Unit )

Central Processing Unit (CPU) or the Indonesian central processing unit (UPS) is the main part in the form of computer hardware and the "brain" of the computer. CPU itself works just like a calculator that we use day - a day to count, but the CPU is much more sophisticated. CPU executes the instructions of a computer program to perform arithmetic operations, logical, and basic input / output system. The term has been used in the computer industry at least since the early 1960s. Shape, design, and implementation of CPUs have changed during their history, but their fundamental operation remains the same.

On large machines, CPUs require one or more circuit boards. On personal computers and small workstations, the CPU is placed in a single silicon chip called a microprocessor. Since the 1970s the microprocessor class of CPUs has almost completely taken over all other CPU implementations. Circuit modern large-scale integrated CPU usually less than four square centimeters, with hundreds of metal pins or interconnected.

Two typical components of a CPU is an arithmetic logic unit (ALU), which performs arithmetic and logic operations, and a control unit (CU), which lays out instructions from memory and decodes and executes them, calling on the ALU when necessary.

How it Works CPU:
When data and / or instructions put-processing devices, first of all placed in the MAA (via Input-storage); when the instruction is accommodated by the Control Unit in the program-storage, but when the data is accommodated in Working-storage). If the register is ready to accept the work execution, the Control Unit will take instruction from program-storage to be added to the Instruction Register, while the memory address containing the instruction stored in the program counter. The data collected by the Control Unit of Working-storage to be accommodated in General-purpose register (in this case the operand-register). If the work performed by instructions are arithmetic and logic, the ALU will take over the operation to perform based on the instruction set. The results are stored in the accumulator. When processing is complete, the Control Unit will take the result in the accumulator to be returned to Working-storage. If the whole operation has been completed, the Control Unit will pick up the processing of Working-storage to fit into the Output-storage. And then of Output-storage, processing results will be displayed to the output devices.

CPU functions:
CPU functions such as a calculator, only much more powerful CPU processing power. The main function of the CPU is to perform arithmetic and logic operations on the data retrieved from memory or from the information entered through some hardware, such as keyboard, scanner, lever control, and mouse. CPU controlled using a set of instructions the computer software. Such software can be run by the CPU to read from storage media, such as hard disks, floppy disks, compact discs, or tape recorder. Instructions are then stored in advance in the physical memory (MAA), which each instruction will be given a unique address called a memory address. Furthermore, the CPU can access data on the MAA to determine the address of the desired data.

When a program is executed, data flow from RAM to a unit called the bus, which connects the CPU with the MAA. The data is then decoded using a process known as the unit pendekoder instructions are capable of translating instruction. The data can then walk to the arithmetic and logic unit (ALU) that perform calculations and comparisons. Data can be stored temporarily by the ALU in a memory location called registers that can be retrieved quickly to be processed. ALU can perform specific operations, including addition, multiplication, subtraction, testing the condition of data in the register, to send the results back to the processing of physical memory, storage media, or register if will process the results of further processing. During this process occurs, a unit inside the CPU called the program counter will monitor instruction successfully executed those instructions that can be executed in the proper sequence and appropriate.

What the ALU? ALU, or Arithmetic Logic Unit is a unit that is tasked to perform arithmetic operations and logic operations defined by instructions. ALU often called machine language because this part ALU consists of two parts, the unit arithmetika and boolean logic units, each of which has its own job specifications. The main task of the ALU is to perform all arithmetic calculations that occurs in accordance with the instruction program. ALU perform all arithmetic operations on the basis of the sum so that the electronic circuits used is called adder.
Besides ALU, CPU also consists of a Control Unit or Control Unit (CU)

The control unit is able to set the course of the program. This component is certainly present in all CPU. CPU in charge of controlling the computer so that there is synchronization between components work in carrying out operations functions. included in the control unit responsibility is to take only instructions from main memory and determines the type of instruction. If there are instructions for arithmetic or logic comparison, the control unit will send instructions to the ALU. The results of the processing of data carried by the control unit to the main memory to be stored, and the time will be presented to the output device. Thus the task of the control unit are:

• Regulate and control the input device (input) and output (output).
• Taking instructions from main memory.
• Taking data from main memory (if necessary) to be processed.
• Send instructions to the ALU if any arithmetic or logical comparisons, and oversees the work of the ALU.
• Stores results to main memory.

Not all computational systems rely on a central processing unit. An array processor or vector processor has multiple parallel computational elements, with no one unit is considered as the "center". In a distributed computing model, this problem is solved by a set of processors are mutually distributed.