What is a Microcontroller?

A microcontroller refers to the smallest computer that can be used on an Integrated Circuit or IC. They have memory of their own, one or more small processors and programmable I/O, all on a single chip.

Technically, a microcontroller is a compact integrated circuit designed to perform specific operations in an embedded system.

Understanding Microcontroller

Understanding Microcontroller

A Microcontroller Unit, or MCU, is also called an embedded controller or embedded computer sometimes because these are compact ICs that act as small, independent computers.

The architecture of a microcontroller is usually based on the Harvard architecture that offers different ways to exchange data between the memory and the processor.

Some are designed on Von Neumann architecture as well that offer similar benefits.

The processors in them can be based on reduced instruction set computing or complex instruction set computing.

If it is based on complex instruction set computing, it will typically have the following:

If it is based on reduced instruction set computing, it will typically have:

Complex instruction set computing, however, emphasizes more on hardware and is much easier to implement than reduced instruction set computing.

It also allows more efficient use of memory with a higher number of clock cycles to execute instructions, although this may result in performance degradation.

Reduced instruction set computing, on the other hand, focuses more on software and therefore offers much better performance as compared to the reduced instruction set computing.

This is because it has a much simpler instruction set and design. However, the software can be quite complex.

The MCUs can perform a number of peripheral functions due to the input and output pins in them. These pins let the microcontrollers act as follows:

The features of the microcontrollers make them preferred and popular, comprising about half of the entire processor market across the globe.

Some of its useful features are:

Microcontroller Types

There are different types of microcontrollers available that are categorized based on different factors such as architecture, bit configuration, bus width memory, instruction set, and so on.

Based on bus width, the microcontrollers can be classified as:

Based on memory, the microcontrollers can be classified as:

Based on Instruction Set Architecture, the microcontrollers can be classified as:

Based on their architecture, the microcontrollers can be classified as:

There are also some other types of microcontrollers that are commonly used, such as:

PIC microcontrollers, with features as follows:

8051 microcontrollers, with features as follows:

Read Also:  What is Conventional Memory? (Explained)

AVR microcontrollers, with features as follows:

ARM microcontrollers, with features as follows:

RENESAS microcontrollers, with features as follows:

How Do Microcontrollers Work?

The microcontrollers typically work by processing the data received by the input pins with the help of the CPU. The final result of the processing is given through the output pins.

Basically, the entire working process of the microcontroller is executed and driven by the synchronous sequential logic circuit. This has specific features such as:

The MCUs also use a large number of logic gates for processing data.

These gates usually need some time to alter the output state. It depends on the inputs. This is called propagation delay.

The interval between every clock pulse must be higher than this delay.

This will make the logic circuit more reliable and stable since it decides the highest operating speed of the microcontroller, which may be different from one MCU to another.

The working process of the microcontroller can be summarized as follows:

The process is completed in quick time since the microcontrollers are high-speed devices. This is ensured by the workings of the other components as follows:

The whole thing is regulated by the clock of the oscillator and everything happens in a matter of a few nanoseconds when the device starts to function.

What is a Microcontroller Used for?

Microcontrollers have a wide range of applications, ranging from communication to motor control, industrial to medical and test and measurement applications.

It is also used in different embedded systems, office machines, home appliances, remote-controlled appliances, and electromechanical systems.

Depending on their sophistication, some of the applications of the MCUs are:

Therefore, the MCUs are used in a wide range of devices to control the small features of the larger components.

It is due to the unique aspect of the microcontrollers, which is that they do not need a multifaceted, front-end operating system.

Microcontroller Examples

Any self-contained system that comes with its own memory, processor, and peripherals can be an example of a microcontroller.

Usually, you will find them in embedded systems and other machinery, such as computers and their peripherals, automobiles, telephones, and appliances.

Here is the list, in alphabetical order, of some of the most common and widely used microcontrollers produced by different manufacturers:

What are the Components of a Microcontroller?

There are mainly three core components of a microcontroller such as the CPU, I/O peripherals and memory along with some additional supporting elements that help in its functioning.

The fundamental elements of a microcontroller are:

The processor or CPU – This, being the brain of the MCU, responds to different instructions and processes them. The instructions include basic arithmetic, logic and I/O functions along with data transfer to communicate commands to the other parts of a larger embedded system.

Memory – This is used to store the data received by the processor of the microcontroller temporarily. There are actually two main memory types in a microcontroller.

There is a non-volatile program memory that stores long-term information regarding the instructions carried out by the CPU without requiring a power source.

Read Also:  What is a File Size? (Explained)

And, there is a volatile data memory to store data temporarily while an instruction is being executed and requires a stable power supply.

I/O peripherals – These act as the interface for the CPU to receive information from the outside world through the input ports and send it to the output devices in the form of binary data to complete the tasks that are external to the MCU.

In addition to these defining elements, the microprocessor also comes with some other additional elements included in it. These are:

ADC or Analog to Digital Converter – This is a circuit that changes analog signals to digital signals which lets the processor communicate with the sensors and other similar external analog devices.

DAC or Digital to Analog Converter – This circuit changes the digital signals to analog signals and helps the processor convey the outgoing signals to the external analog devices.

System bus – This is the communication pathway or the wire that connects all the different parts of the MCU together.

Serial port – This is an I/O port that allows the MCU to connect to other outside components. It functions in the same way as a parallel port or USB with the only difference being the ways of exchanging bits.

Timers and counters – The counter is used to manage the counting of the external pulses. The timer conducts different clock tasks and times different functions of the microcontrollers such as pulse production and modulations, oscillations, frequency measurement, and others.

Interpretation controller – This is used to supply delayed control with both internal and external interpretation to the running application.

Block with special function – This block with additional ports is found in a few specific types of microcontrollers used in special devices such as robots, space systems and others to perform specific types of tasks.

How is a Microcontroller Programmed?

Typically, the microcontrollers are programmed in three basic steps involving writing the code, compiling the code files and uploading it.

In the earlier days assembly languages were used for programming but the modern MCUs are programmed using higher-level languages such as Java and C++.

The basic steps involved in programming a microcontroller are:

Writing the program code – This is the first step of programming and is usually done in C, though some compilers prefer using other programming languages as well.

You may use any software to write the code, even Notepad, but choosing a better version such as Notepad++ that supports highlighting the syntax will make writing much easier.

Compiling – This is the second step to follow which involves converting the human-readable code into a machine-readable code. There may be one or more files to compile before you upload the code for the microcontroller.

Uploading the file – While uploading the program file for the EEPROM or flash, you will need a physical connection to the microcontroller from the computer and a dedicated programmer or a USB programmable chip.

How is a Microcontroller Powered?

Ideally, the microcontrollers are powered by any of the three main DC voltage sources such as wall adapters, batteries, or via the USB port in the computer.

Wall adapter – Also called wall-warts, these big and bulky adapters protrude like a wart. One with an output voltage corresponding to that of the devices in the circuit should be used. However, if it is higher than that, you will need to use a voltage regulator along with it as well.

Batteries – There are different types of batteries with varied voltage ratings and therefore one with the desired voltage should be used.

However, you must also consider the periods of operation so that it can supply the rated output to the circuit. Once again, if the rating is higher than what is desired, it will also need using a voltage regulator.

USB – This is perhaps the best power source and the easiest way to get a smooth supply of 5 volts of direct current.

The amount of power required by a microcontroller is determined by the needs of the device but usually it is within a specific range.



Read Also:  What is Optane Memory? Uses, Pros & Cons

Microcontroller vs Microprocessor

Why are Microcontrollers Preferred?

Microcontrollers are preferred because they are specially designed and optimized to perform specific tasks while using very little power.

These are also ideal for use in embedded systems as well as for common computing applications since they can support more versatile and complex computing operations depending on their capabilities and instruction sets.

Questions & Answers:

Do Microcontrollers Have Logic Gates?

Yes, the microcontrollers are, in fact, made up of thousands, and even millions, of logic gate circuits.

Does a Microcontroller Store Data?

Yes, the microcontrollers store data in the data memory. Usually, the microcontrollers come with their own RAM to store the data of the running programs.

However, it is volatile and stores data temporarily or as long as there is a constant power supply.

How Much RAM Does a Microcontroller Have?

The amount of RAM in a microcontroller is usually around 128 bytes or 1 MB to 256 KB, which is not very big to hold a lot of RAM for your application.

However, you should check with the data sheet of the MCU to be doubly sure about the amount of RAM.

How Much ROM is in a Microcontroller?

The amount of ROM in a microcontroller is much higher than the amount of RAM in it. For example, in an 8051 microcontroller the amount of ROM or code memory is 4 KB. Typically, in general MCUs, the amount ranges between 32 KB to 2 MB.

What is the Voltage of a Microcontroller?

Most of the microcontrollers may run at a voltage of 3 volts, while there are a few that can operate even at a lower voltage supply of less than 2 volts.

Typically, the modern microcontrollers consume significantly low power to operate. In fact, their operating voltage typically ranges between 1.8 volts and 5.5 volts.

Is a Microcontroller an IC?

Yes, a microcontroller is a single Integrated Circuit or IC. It is designed to perform special tasks and is intended to be used for a particular application.

Which Language is Best for a Microcontroller?

Microcontrollers were initially programmed in assembly language only, but today, the most popular option is the C programming language. The most commonly used languages used in the microcontrollers are C or C++.

These are reliable and can ensure higher efficiency and speed in performance. Apart from that, MCUs can also be programmed in other common languages such as JavaScript and Python.


Microcontrollers are used in almost all electronic devices today, including computers.

They offer a much more practical, flexible and affordable solution to meet several challenges in modern systems and their circuit design.

Designed to perform specific tasks, they add to the overall performance of the system.