INTRDUCTION: IC 8051 - MICROCONTROLLER

8051 MICROCONTROLLER

This micrcontroller chip was invented and manufacture by INTEL company. Before 8051 microcontroller another microcontroller chip was manufactured i.e. Intel 8031. And after 8051 they launched 8052 microcontroller.

Difference between all the three is mentioned below:

Feature 8051 8052 8031

Interrupt sources 6 8 6
Serial port 1 1 1
I/O pins 32 32 32
Timers 2 3 2
RAM (bytes) 128 256 128
ROM (on-chip program 4K 8K 0K
space in bytes)

Microcontrollers and embedded processors

General-purpose microprocessors contains:

1. No RAM
   
2. No ROM
3. No I/O ports
4. No Timer
5. Serial COM Port
   

Microcontroller has:

1. CPU (microprocessor)
2. RAM
3. ROM
4. I/O ports
5. Timer
6. ADC and other peripherals

There are so many applications of embedded processors and microcontroller:

1. Home: Appliances, intercom, telephones, security systems, garage door openers, answering machines, fax machines, home computers, TVs, cable TV tuner,VCR, camcorder, remote controls, video games,cellular phones, musical instruments, sewing machines, lighting control, paging, camera, pinball machines, toys, exercise equipment.

2. Office: Telephones, computers, security systems, fax machines, microwave, copier, laser
printer, color printer, paging.

3. Auto: Trip computer, engine control, air bag, ABS, instrumentation, security system,
transmission control, entertainment, climate control, cellular phone, key less entry.

Pin diagram

Architecture of Intel 8051 Microcontroller

Criteria for choosing a Microcontroller:

• Meeting the computing needs of the task at hand efficiently and cost effectively
• Speed
• Packaging
• Power consumption
  The amount of RAM and ROM on chip
• The number of I/O pins and the timer on chip
• How easy to upgrade to higher performance or lower power-consumption versions
  Cost per unit

INTRODUCTION TO EMBEDDED SYSTEMS

*An embedded system is a single-purpose
computer built into a larger system for the purposes of controlling and monitoring the system.

A general purpose computer (e.g. a personal computer) is defined not to be an embedded system.




*A specialized computer system that is part of a larger system or machine. Typically, an embedded system is housed on a single microprocessor board with the programs stored in ROM.



Virtually all appliances that have a digital interface -- watches, microwaves, VCR's, Cars -- utilize embedded systems. Some embedded systems include an operating system, but many are so specialized that the entire logic can be implemented as a single program.

Examples: Cell phones, D.S.TV decoders, MP3 players, ABS breaking systems, Satellite guidance avionics etc.