What is CPU ?

Recent development of CPU

What is CPU ?

The central processing unit (CPU) is the heart of the computer system. All processing is carried out by the CPU.

The CPU is built on a single chip called a microprocessor. The main f unction of the CPU is to accept and execute the instructions stored in the computer's main memory. 

The CPU consists of two major components: the control unit (CU) and the arithmetic and logic unit (ALU)

(1) The control unit

The control unit controls the overall operations of the computer. Some major functions of the control unit are : 

1. To control access to the main store.
2. To control the sequence in which instructions are executed. 
3. To regulate the timing of all operations carried out within the CPU.
4. To send and receive control signals to and from peripheral devices.

(2) The arithmetic and logic unit (ALU)

The arithmetic and logic unit performed the arithmetic and logical operations. It is responsible for the manipulation of data which is brought from the memory unit or the control unit. The arithmetic and logic unit consists of an accumulator (ACC), a set of logic circuits , and a status register (SR).

Recent development of microprocessors

In recent year, the advances in hardware outpace that in the software. The most significant being the advances in microprocessors and storage media.

Faster CPUs from different companies like INTEL, CYRIX, AMD, are coming out every few months. There are mainly two streams of microprocessors that are competing over each other. One of them is CISC ( complex instruction set computer , mainly from Intel) and the other is RISC ( reduced instruction set computer, mainly from MOTOROLA). The main difference between them is the latter one use simpler set of instruction. Both types of design have their advantages.

Nowadays, hybrid structure, combination of CISC and RISC, of microprocessor exits which can take the advantages of both designs.

This is the CPU of AMD	This is the CPU of Intel

The famous Pentium processors are based on a CISC structure while PowerPC processors are based on a RISC structure. Some processors like CYRIX 6X86 use a hybrid structure to take advantage of the two. The speed for microprocessor has been pushed to the limit. Now the Pentium 4 with 2GHz has came to the market, we sure that more and more new product will be seen on the market soon.

Little history of Pentium

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