Introduction

MICROPROCESSOR

Microprocessor is a device which may perform the several device actions such as transistors, Integrated circuits and resistors. The Microprocessor is an inbuilt device which consists of millions of electronic components which are listed above. This Microprocessor is used in computers.

Applications of Microprocessor and Microcontrollers:

1. Consumer electronics

2. Camcorders, cameras

3. Household appliances like Television, DVD player, washing machine, fridge, microwave oven etc.

4. Telecommunication appliances like cellular telephones, Telephone switches and multimedia applications etc….

5. Computer peripherals like printers, scanners, fax machines etc...

6. Health care like different kinds of scanners EEG, ECG machines etc...

7. Banking and retail applications like ATM, Currency counts,

8. Card readers i.e. barcode, smart card readers, hand held devices etc...

Microprocessor term has come to be known in general purpose digital computer central processing unit (CPU). Although popularly known as computer on a chip.

The below figure shows the block diagram of CPU

* The cpu contains ALU (Arthiematic and Logical Unit)

* A program counter (PC)

* A stack pointer (SP) and working register

* A clock counter

* An Interrupt circuit.

To make the complete microcomputer one must add memory usually read only memory (ROM), read access memory (RAM), memory decoders, an oscillator and a number of inputs, output devices such as parallel and serial data ports.

*The main use of microprocessor is that to read the data, perform extensive calculations on that data and stores these calculations in a mass storage device of display the results as per human use.

*The microprocessor programs are stored in mass storage device and loaded into RAM

*A few microprocessor programs are stored in ROM

*The ROM based programs are primary small fixed programs that operates peripherals and other fixed devices that are connected to the system.

8086 MICROPROCESSOR

The 8086 was INTEL`s first 16-bit microprocessor. It has a capability of addressing about 1 megabyte of memory. It uses a segmented memory. 8086 prefetches up to 6 instruction bytes from memory and arrange them in order to speed up instruction execution. The below figure shows the 8086 microprocessor.

From the above figure you observe that it consists of 40 pins which are specialized by their names. To operate this microprocessor +5v power supply is required. Remind one thing, generators requires prime movers for starting purpose, so same procedure is required in microprocessor it also needs the prime mover. The clock input signal is generated by 8284 clock generator/driver chip. The execution time varies between 2 clock cycles and 30 clock cycles.

Versions of Microprocessor

There are three versions in 8086 microprocessor

1. 8086: This version operates from a clock frequency of 5MHZ.

2. 8086-2: This version operates under clock frequency 8MHZ.

3.8086-4: This version operates from a maximum clock frequency of 4MHZ.

Family of 8086 microprocessor:

The 8086 family consists of two types of 16-bit processor, they are 8086 and 8088.

8088: This processor is an 8-bit processor. It is the external data path to memory.

*For the requirement o 16-bit processor operation there is a necessity of two 8088 processors

*This process access memory

8086: This processor has a 16- bit external data path compare to 8088, 8086 is preferred most due to constructional features and reliability.

*The 8086 microprocessor is used in designing the IBM personal computers

*The 8086 microprocessor is designed using HMOS technology, and packs approximately 30,000 transistors on the chip.

*It is packed in a 40 pin plastic DIP (Dual in line Package) or a 40pin CERDIP (ceramic DIP)

*The INTEL 8088 has the same instruction set registers as the Intel 8086, but has only 8bit external bus, although the internal
architecture is 16-bits.