A microcontroller (mcu or µc) is a small computer on a single integrated circuit consisting of a relatively simple CPU combined with support functions such as a crystal oscillator, timer, watchdog, I\O etc.
Microcontrollers are designated for small applications. Thus, in contrast to the microprocessors used in personal computers and other high performance applications, simplicity is emphasized. Microcontrollers operate at frequency as low as 12 MHz, as this is adequate for many typical applications, enabling low power consumption (mill watt or nanowatt).
Microcontroller is used in automatically controlled products and devices, such as automatic control system, appliances and toys.
| Microprocessors | Microcontroller |
|1. It is just a CPU. |1.Include CPU+ I/O+ RAM+ROM+TIMERS+SERIAL COMM |
| |On a single chip. |
|2. Operates at high frequency ie, 2.06GHz. |2.Operates at a low frequency ie,12 MHz |
|3. It is general purpose, i.e. more than on operation can be perform |3. It is single purpose ,i.e. can perform only one task at a time. |
|simultaneously. | |
|4.Costly |4. Cheap. |
Introduction to 8051 microcontroller
Input /Output pins 32
RAM 128 bytes
ROM 4K bytes
Timers 2
Interrupt sources 6
Serial port 1
Pin Diagram and Description