Different Types Of Microcontrollers Used In Embedded System

Hello guys, welcome back to my blog. In this article, I will discuss the different types of microcontrollers used in embedded systems, features of different types of microcontrollers, working of microcontrollers, advantages, and disadvantages of microcontrollers, etc.

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Types Of Microcontrollers

Microcontroller

A decade back the process and control operation was performed by microprocessors only. But nowadays situations are completely changed and it is controlled by the device called Microcontroller and it is used for specific tasks. The development is so radical that we can’t find any electronic gadget without the use of a microcontroller. So, here we just define that the microcontroller is a single-chip computer with all the peripherals like RAM, ROM, I/O ports, timers, ADC’s, etc., at the same chip.

A microcontroller is a single-chip microcomputer fabricated from VLSI fabrication. Microcontrollers are embedded inside the devices to control the activities and features of a product. Hence, they can also be related to embedded controllers based on this reason normally a microcontroller is also known as an embedded controller.

The microcontroller word explains that the word micro is commonly used in electronics and usually in science micro mean 10^-6 and the device includes transistors that are small in size. From here, we define that a microcontroller is a pretty small device employed to control the devices. A microcontroller saves cost, saves power consumption, and does the circuit compact. Nowadays we use different types of microcontrollers in a number of applications because it gives an effective output.

A microcontroller is an integrated circuit that comprises a processor core along with memory, associated circuits, and that controls some of the functions of electronic devices or systems. Microcontrollers are primarily employed in devices that require a degree of control to be employed by the user of the device. Today many types of microcontrollers are available in the market with various term lengths such as 4bit, 8bit, 64bit, and 128bit microcontrollers.

A microcontroller can receive inputs from the device they control and maintain control by sending the device signals to various parts of the device. They run one particular program and are committed to a single task. They are low power consumption devices with dedicated input devices and small LED or LCD show outputs. A great example is the Tv’s microcontroller, It takes input from a remote and produces its output on the TV screen.

Microcontrollers normally must have low power consumption conditions since many devices they manage are battery operated. Microcontrollers are quite suited for long-lasting battery applications. The dominant role of microcontrollers being used nowadays is implemented in other apparatus.

Types of microcontrollers

Nowadays different types of microcontrollers are available in the market with various features those are like:

1. PIC Microcontroller
2. ARM Microcontroller
3. 8051 Microcontroller
4. AVR Microcontroller
5. MSP Microcontroller

Let’s discuss one by one “types of microcontrollers”.

01. PIC Microcontroller

PIC is a family of microcontrollers manufactured by microchip technology, originally produced by the general instrument’s microelectronics division. The name PIC originally referred to Peripheral Interface Controller, and currently, it is expanded as Programmable Intelligent Computer.

PIC devices are familiar with both industrial developers and hobbyists due to their low cost, wide availability, large user base, extensive collection of application notes, serial programming, free development tools, and reprogrammable flash memory capability.

Features of PIC16F877

01. Core features

1. High- performance RISC CPU
2. Up to 8k × 14 words of FLASH program memory
3. 35 instructions
4. 368×8 static RAM-based data memory
5. Up to 256 × 8bytes of EEPROM data memory
6. Interrupt capability (up to 14 sources)
7. Three addressing modes (Direct, Indirect, relative)
8. Power-on Reset (POR)
9. Harvard architecture memory
10. Power saving SLEEP mode
11. Wide operating voltage range:2.0V to 5.5V
12. High sink/source current:25mA
13. Accumulator based machine

02. Peripheral features

1. 3Timer/Counters
2. 2 Capture, Compare, PMW modules
3. 10bit channel analog to digital converter
4. USART with 9bit address direction
5. Synchronous serial port including master mode and I2C Master/Slave
6. 8bit parallel slave port

03. Analog features

1. 10 bit up to 8 channel analog to digital converter
2. Brownout Reset
3. Analog comparator module(Programmable input multiplexing from device inputs & comparator outputs are externally accessible).

Block Diagram Of PIC Microcontroller

The PIC microcontroller consists of 8-channels, 10 bit Analog to Digital converter. The performance of the A/D converter is controlled by these special function registers. Early models of PIC had read-only memory or field programmable EPROM as program storage, some with provision to erasing memory. All present models use flash memory for program storage and more current models support the PIC to reprogram itself.

The instruction set also differs by model, with extra powerful chips adding instructions for digital signal processing functions. PIC holds a built-in data memory, data bus, and a dedicated processor for providing all I/O purposes. There are many PICs that started with PIC16F84 and PIC16C84.

The lower bits are stored in ADRESL(8bits), and the upper bits are stored in the ADRESH register. Microchip has newly introduced flash chips with types that are much more attractive, such as 16F628,16F877, and 18F452.

Advantages Of PIC Microcontroller

01. They are reliable and the malfunctioning of PIC percentage is very light and the performance of PIC is really fast because of employing RISC architecture.

02. Power conception is also much less compared to different microcontrollers. When we discuss in the programmer point of view interfacing is really easy, moreover, we can connect analog devices directly without any additional circuitry and use them, programming is also very easy when compared to different microcontrollers.

03. It is consistent and the faculty of PIC percentage is very low. Using RISC architecture the performance is high Speed.

Disadvantages Of PIC Microcontroller

01. The length of the program will be big because of using RISC(35instructions).

02. Program memory is not accessible and only one single accumulator is present.

Applications Of PIC Microcontroller

01. These microcontrollers are used in electronic devices such as mobile’s, computers, and embedded operating systems.

02. PIC microcontrollers are the very smallest microcontrollers in the world that can be created to carry out a huge range of tasks so, this microcontroller is often used for a high range of tasks. Next comes ARM microcontroller in types of microcontrollers.

02. ARM Microcontroller

Arm full form or stands Advanced Risk Machine, originally acorn RISC machine is a family of reduced instruction set computing (RISC) architectures for computer processors, configured for various environments. It is 1 of the extensive and most licensed processor cores in the world.

The first arm processor was developed in the year 1978 by Cambridge University, and the first ARM RISC processor was created by the acorn group of computers in the year 1985. Arm holdings develop the architecture and license it to different companies, who design their own products that perform one of those architectures including Systems-on-Chips (SoC) and Systems-on modules (SoM) that incorporate memory, interfaces, radios, etc.

The ARM processors have a less amount of transistors because they have a reduced instruction set, which provides a smaller size for IC. Through being space-efficient also. Most maximum of electronic devices consists of these processors. By joining the ARM processors with RAM, ROM, and other peripherals in one single chip, we get an ARM microcontroller.

Features Of ARM Microcontroller

1. There are only 25basic instruction types in this designed processor.
2. Most of the operations are implemented through registers
3. All instructions can have some conditions with them.
4. There can be various modes of addressing in this processor.
5. Manual stock manipulation is done. Stack addressing and subroutines are explicitly programmed.
6. The 32-bit mode microprocessor made it possible to have access to memory and data manipulation saved in these 32-bits.
7. The address range of this processor is 26bit wide. It allows 64megabytes of memory to be accessed directly.
8. Usually, there is a single cycle execution.
9. There is no support in the processor for misaligned memory accesses.

Block Diagram Of ARM Microcontroller

It is a 32-bit processor allowing several advantages over other microcontrollers. It is a 32bit microcontroller therefore all instructions are 32 bit long and are executed in a single cycle. It is a hardware architecture. For communication with ROM and RAM, this architecture provides separate instruction buses and data buses.

It consists of an instruction set to make the arithmetical, logical, and Boolean operation. The ARM is a load-store architecture, next the instructions are executed conditionally. It has a 3stage pipeline that fetches the instructions then decodes them and then ultimately
executes the instruction.

The last thing that we require to understand is how ARM will be used and the way in which the chip appears. The different signals that interface with the processor are input, output, or supervisory signals which will be employed to control the ARM operation.

Advantages Of ARM Microcontroller

1. They are cheap compared to other processors
2. They are made with such features that it consumes less power.
3. The devices with ARM processors can have a much better battery life than other processors.
4. They perform one operation at a time and so work faster.
5. The availability and application support has also made the users choose ARM processors.

Disadvantages Of ARM Microcontroller

1. It is not binary compatible with x86, which implies you cannot run windows on it very soon.
2. Some ARM processor clocks frequencies, which speeds and memory bandwidths are limited in such cases.
3. The scheduling of instructions makes debugging difficult.
4. The performance of these processors greatly depends on the execution. If the programmer doesn’t execute it properly then it can take a long time to work properly.

Applications Of ARM Microcontroller

1. ARM processor finds applications in digital TVs, set-top boxes, smartphones, mobiles, and laptops, etc.
2. ARM processors are founds in networking applications like home gateways, DSL modems
3. ARM processors are found in numerous market segments, including networking, automotive, mass storage. With each segment, ARM processors can be found in multiple applications. Next comes 8051 microcontrollers in types of microcontrollers.

03. 8051 Microcontroller

In 1981, intel launched an 8-bit microcontroller called the 8051. It is an extremely integrated single chip, which consists of on-chip CPU(Central Processing Unit), EPROM/PROM/ROM(Erasable Programmable Read-Only Memory), I/O, serial& parallel, timers, RAM(Random Access Memory), interrupt controller, serial interfacing ports, A/D& D/A converters, oscillatory circuits.

A microcontroller internally consists of all features needed for computing systems and functions as a computer without combining any external digital parts into it. It is able of handling Boolean functions and it has several bit handling instructions that can be clearly understood by the programmer.

Features Of 8051 Microcontroller

1. 40 pin DIP(Dual Inline Package)
2. 8-bit data bus &16-bit address bus
3. 128byte RAM(on-chip data memory)
4. 4KB ROM(on-chip program memory)
5. The maximum external data/program memory that can be interfaced is of 64KB
6. 4 parallel ports of 8-bit
7. 32 input/output bidirectional lines
8. On-chip oscillator which is having of 12MHz
9. 5volts DC power supply
10. On-chip 2 timers and counters (16bit)
11. There are 5 interrupts in microcontroller {(2hardware: IN1&IN2 ) &(3software Interrupts: Timer0, Timer1& serial port)}
12. It has an on-chip Programmable power-saving circuit
13. It uses Harvard 2RISC architecture
14. On-chip serial port. It is full-duplex type, asynchronous with Programmable baudrate{(Universal Asynchronous Receiver)(Transmitter: I2C,SPI,USB)&(protocols:set&rules)}
15. 111 total instruction set in 8051 Microcontroller.

Block Diagram Of 8051 Microcontroller

There is an interrupt that is very useful as it helps in the case of emergency operations. An interrupt gives us a mechanism to put on hold the ongoing operations, execute a subroutine, and then again resume another operation. When the subroutine is completed, then the execution of the main program starts. Generally, there are 5 interrupts that are there in the 8051 microcontrollers. External interrupts could be low-level triggered or negative edge triggered. When all these interrupts are activated, set the corresponding flogs except for the serial interrupt. The interrupt flags are cleared during the processor branches to the Interrupt Service Routine (ISR).

Microcontrollers require a program that is a collection of instructions. This program tells the microcontroller to do specific tasks. These programs require memory on which these can be saved and read by the microcontroller to perform specific operations of a particular task. The memory which is utilized to Store the program of the Microcontroller is identified as code memory or program memory of applications. It is known as ROM memory of Microcontroller that also requires a memory to store data or depends temporarily on the Microcontroller. The data memory of 8051 used to store the data temporarily for operation is known as RAM memory.

Basically, the bus is a collection of wires which work as a communication channel or medium for the transfer of data. In this Microcontroller, we have an address bus used to address memory locations and to transfer the address from CPU to memory of the Microcontroller and there is another bus called Data Bus used to carry data of a particular application.

Generally, we understand that the Microcontroller is a device, therefore it requires clock pulses for its operation of Microcontroller applications. For this purpose, Microcontroller 8051 has an on-chip oscillator that works as a clock source for the Central Processing Unit of the Microcontroller. The output pulses of the oscillator are stable. Therefore, it enables synchronized work of all parts of the 8051 Microcontroller.

Normally microcontrollers are used in embedded systems to control the operation of machines in the Microcontroller. Therefore to connect it to other machines, peripherals, or devices we require input/output interfacing ports in the Microcontroller interface. Timers are used for the measurement of intervals to determine the pulse width of pulses.

Advantages Of 8051 Microcontroller

1. The low time required for performing an operation.
2. The processor chips are very small and versatility occurs.
3. Due to their higher integration, the cost and size of the system are reduced.
4. The Microcontroller is easy to interface additional RAM, ROM, and I/O ports.
5. At the same time, many tasks performed so the human effect can be saved.
6. Without any digital parts, it can act as a microcomputer.
7. It is easy to use, troubleshooting, and system maintenance are simple.

Disadvantages Of 8051 Microcontroller

1. The Microcontroller cannot interface high power devices directly.
2. It has a more complex structure as compared to a microprocessor.
3. It only performed a limited number of executions simultaneously.
4. Mostly used in micro- equipment.

Applications Of 8051 Microcontroller

1. Consumer appliances (TV tuners, remote controls, computers, and sewing machines)
2. Home appliances (TV’s, VCR, video games, camcorder, music instruments, home security systems, garage door openers….etc.)
3. Communication systems (Mobile phones, intercoms, answering machines, paging devices)
4. Office (Fax machines, printers, copiers, lazar printers)
5. Automobiles (Airbags, ABS, engine control, transmission control, temperature control, keyless entry)
6. Aeronautical and space
7. Medical equipment
8. Defense systems
9. Industrial process and flow control
10. Robotics
11. Radio and networking equipment
12. Remote sensing
13. Prepaid energy meter using Microcontroller and GSM modem
14. Used in Power theft detection. Next comes AVR microcontroller in types of microcontrollers.

04. AVR Microcontroller

AVR is developed in the year 1966 by Atmel Corporation. The architecture of AVR was developed by Alf-Egil Bogen and vegan wollan. AVR derives its name from its developers and stands for Alf-Egil Bogen Vegan Wollan RISC microcontroller, also known as Advanced Virtual RISC.

AVR microcontrollers are available in three categories:

1. TinyAVR: Less memory, small size, fit only for more simplistic applications.
2. MegaAVR: These are the most popular ones having a good amount of memory, a higher number of inbuilt peripherals, and are suitable for moderate to complex applications.
3. XmegaAVR: Used commercially for complex applications, which require large program memory and high speed.

AVR is one of the first microcontroller families to use on-chip flash memory for program storage, as opposed to a one-time programmable ROM, EPROM, or EEPROM used by the other microcontrollers at the time. AVR was the modified Harvard architecture machine, where programs and data were stored in the separate physical memory system that appears in different address spaces, but having the strength to browse data or information things from program memory victimization particular directions. AVR isn’t an associate degree signifier and doesn’t symbolize something specially. AVR microcontrollers are found in embedded systems.

Features Of AVR Microcontroller

1. 32×8 general working function registers.
2. 32k bytes of in-system self-programmable flash program memory.
3. 2k bytes of internal SRAM.
4. 1024bytes of EEPROM.
5. Available in 40pin DIP, 44lead QTFP, 44-pad QFN/MLF.
6. 32 programmable I/O lines.
7. 8 channel, 10bit ADC.
8. Harvard architecture.
9. UART, I2C, SPI protocol support.
10. A variety of serial interfaces, including I2C compatible Two-wire interface synchronous/Asynchronous SPI.

Block Diagram Of AVR Microcontroller

The AVR microcontrollers are based on the advanced RISC architecture and consist of 32×8-bit general purpose working registers. Within one single clock cycle, AVR can take inputs from two general-purpose registers and put them to ALU for carrying out the requested operation, and transfer back the result to an arbitrary register. The ALU can make arithmetic as well as logical operations. Besides the inputs from the register or within the register and a constant. Single register operations such as taking a complement can also be executed in ALU. We can see that AVR doesn’t have any register-like accumulator as in 8051 families of microcontrollers: the operations can be performed between any of the registers and can be stored in either of them.

AVR follows the Harvard architecture format in which the processor is equipped with separate memories and buses for the program and the data information. Here while an instruction is being executed, the next instruction is pre-fetched from the program memory. Since AVR can do single cycle execution, it implies that AVR can execute 1million instructions per second if the cycle frequency is 1MHz.

Advantages Of AVR Microcontroller

1. The AVR microcontrollers having high-performance features.
2. These preforms any instruction with high speed
3. It consumes less power
4. Cheap and very small in size
5. It cancels the machine cycle and executes the pipeline Operation with the clock cycle as the instruction cycle.

Disadvantages Of AVR Microcontroller

1. It is available in single-source only i.e., Atmel
2. Atmel AVR’s have fairly low power.

Applications Of AVR Microcontroller

1. Mobile phones
2. Auto-motive industry
3. CD/DVD players
4. Washing machines, microwave ovens
5. Cameras
6. Modems and routers
7. Security alarms
8. Electronic measuring instruments. Next comes MSP microcontroller in types of microcontrollers.

05. MSP Microcontroller

MSP is one of the family members from Texas instruments. This is a 16-bit CPU and RISC-based, Mixed-Signal Processor. In this, the MSU’s have the right mix of intelligent peripherals, easy of use, low power consumption for thousands of applications.

In this, the controller’s appearance is directly linked to the 16-bit data bus, seven addressing modes, and the decreased instruction set which provides a shorter and denser programming code for high-speed performance.

Features Of MSP Microcontroller

1. Mixed-signal microcontroller family
2. 16bit CPU
3. Low cost, low power consumption
4. Ultra low power architecture and flexible clock system extend battery life
5. Low operation voltage (from1.8v to 3.6v)
6. Zero power Brown Out Reset(BOR)
7. Enhanced libraries to benefit several applications such as capacitive touch, metering metrology, low power design, and debugging
8. Extensive interrupt capability relieves the need for polling
9. Flexible and powerful processing capabilities
10. Seven source address modes
11. Four destination address modes
12. Only 27 core instructions
13. Large register file
14. Efficient table processing
15. Fast hex to decimal conversion

Block Diagram Of MSP Microcontroller

In this, there is a clock system at the start used to provide timings, and these are used to operate various peripherals. Here it takes input from Xin and there is an output for this clock system that is Xout used for controlling the external devices and the ACLK and SMCLK are used to
control internally but MCLK is mainly used for CPU.

There is a Flash used for the coding and RAM to store the data and there is an analog and digital peripheral to get the desired output in the desired signal. Mainly there are two buses called Memory Addressed Bus(MSB) and Memory Data Bus(MDB) that are used to carry the address and data these are interfacing with the CPU and memories. There is a timer used to provide the alarms and there is a protection system to provide safety for a microcontroller.

Advantages Of MSP Microcontroller

1. The value of MSP value-line controllers are cheaper than the higher-end ATMega controllers used in the Arduino platform.
2. In this microcontroller, we don’t need any external crystal, because the MSP microcontrollers can run at the full 16MHz from their internal clock source.

Disadvantages Of MSP Microcontroller

The MSP microcontrollers are based on the old version of GCC-it works well enough but has limited support for newer devices.

Applications Of MSP Microcontroller

1. It is used for factory control and automation applications.
2. It is used in grid infrastructure and metering applications.
3. It is used in portable test and measurement equipment.
4. It is used in health, medical and fitness applications.

Conclusion

Today there is no electronic gadget on the earth that is designed without different types of microcontrollers. Therefore, the modern days’ different types of microcontrollers have marked a revolutionary change in every aspect of the automobile designing and manufacturing processes because of their flexibility and adaptability. So, from the above information, we definitely say that there is a lot of importance to the types of microcontrollers.

I hope this article may help you all a lot. Thank you for reading. If you have any doubts related to this article”different types of microcontrollers”, then comment below.

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About The Author

Chetan Shidling

Automotive | Technical Blogger | Engineer | Content Creator

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