Communication Protocols in Embedded Systems - Types, Advantages & Disadvantages (2022)

Communication Protocols are a set of rules that allow two or more communication systems to communicate data via any physical medium. The rules, regulations, synchronization between communication systems, syntax to be followed and semantics are all defined by the term protocol. Protocols can be implemented by both hardware and software or combination of both. Analog and digital communication systems use various communication protocols widely. In addition, each protocol has its own application area.

Formal Communication: Definition, T...

Formal Communication: Definition, Types, Advantages, and Limitations

Communication Protocols in Embedded Systems

Embedded System is an electronic system or device which employs both hardware and software. A processor or controller takes input from the physical world peripherals like sensors, actuators etc., processes the same through appropriate software and provides the desired output.

In this case, the components have to communicate with each other to provide the anticipated output. Each communicating entity should agree to some protocol to exchange information. Many different protocols are available for embedded systems and are deployed depending upon the application area.

Fig. 1 – Introduction to Communication Protocols

In general, the communication protocols is associated with physical layer describing the signals incorporated, signal strength, hand shaking mechanism, bus arbitration, device addressing, wired or wireless, data lines etc.

(Video) Communication protocol in Embedded System | Synchronous & Asynchronous communication

The processes such as system configuration, selection of baud rate and transmitting & receiving data is associated with application layer.

Types of Communication Protocols in Embedded Systems

Communication protocols are broadly classified into two types:

  • Inter System Protocol
  • Intra System Protocol

Fig 2 – Classification of Communication Protocols

Inter System Communication Protocols

Inter system protocols establish communication between two communicating devices i.e. between PC and microprocessor kit, developmental boards, etc. In this case, the communication is achieved through inter bus system.

Fig. 3 – Inter System Communication Protocols

Types of Inter System Communication Protocols

Inter system protocol can be categorized into:

  • USB Communication protocols
  • UART Communication protocols
  • USART Communication protocols

USB Communication Protocols

Universal Serial Bus (USB) is a two-wired serial communication protocol. It allows 127 devices to be connected at any given time. USB supports plug & play functionality.

USB protocol sends and receives the data serially between host and external peripheral devices through data signal lines D+ and D-. Apart from two data lines, USB has VCC and Ground signals to power up the device. The USB pin out is shown in Figure 4 below.

Fig. 4 – USB Pin Out

Data is transmitted in the form of packets where two devices communicate each other. Data packets compose of 8 bits (byte) with LSB (Least Significant Bit) transmitted first.

USB associates NRZI (Non Return to Zero Invert) encoding scheme to transmit data with sync field to synchronize the host system and receiver clock signals.

(Video) Protocols : UART | SPI | I2C | Embedded Systems Communication Protocols

In USB, data is transferred in three different speeds such as:

Fig. 5 – USB speeds

Advantages of USB Communication Protocol

The advantages of USB Communication Protocol are as follows:

  • Fast and simple.
  • It is of low cost.
  • Plug and Play hardware.

Disadvantages of USB Communication Protocol

The disadvantages of USB Communication Protocol are as follows:

  • Needs powerful master device.
  • Specific drivers are required.

UART Communication Protocols

Universal Asynchronous Receiver/Transmitter (UART) is not a communication protocol but just a physical piece of hardware which converts parallel data into serial data. Its main purpose is to transmit and receive data serially.

UART is also two-wired i.e., the serial data is handled by Tx (Transmitter) and Rx (Receiver) pins.

UART transmits data asynchronously, which induces that no clock signal is associated in transmitting and receiving data. Instead of clock signal, UART embed start and stop bits with actual data bits, which defines the start and end of data packet.

When receiver end detects the start bit, it starts to read the data bits at specific baud rate meaning both transmitting and receiving peripherals should work under same baud rate. UART works under half duplex communication mode meaning it either transmits or receives at a time.

Fig. 6 – UART Frame

Example: Emails, SMS

USART Communication Protocol

Universal Synchronous Asynchronous Receiver/Transmitter (USART) is identical to that of UART with only added functionality synchronous. That is, the transmitter will generate a clock signal which will be recovered at the receiver end from the data stream transmitted without knowing baud rate ahead.

UART works under full duplex communication mode meaning it can transmit and receive data at same time.

(Video) Embedded Systems Protocols Serial-UART I2C SPI Communication

USART encompass the abilities of UART, which enables application of both depending on the applications area.

Fig. 7 – USART Frame

Example: Telecommunications

Advantages of UART/ USART Communication Protocol

The advantages of UART/ USART Communication Protocol are as follows:

  • Clock signal is not required
  • Cost effective
  • Uses parity bit for error detection
  • Requires only 2 wires for data communication

Disadvantages of UART/ USART Communication Protocol

The disadvantages of UART/ USART Communication Protocol are as follows:

  • Doesn’t support multiple master slave functionality
  • Baud rate of communicating UART should be within 10 percent of each other

Intra System Communication Protocols

The Intra system protocol establishes communication between components within the circuit board. In embedded systems, intra system protocol increases the number of components connected to the controller.

Increase in components lead to circuit complexity and increase in power consumption. Intra system protocol promises secure access of data from the peripherals.

Types of Intra System Communication Protocols

Intra system protocol can be categorized into:

  • I2C Protocol
  • SPI Protocol
  • CAN Protocol

I2C Communication Protocols

Inter Integrated Circuit (I2C) is a serial communication protocol developed by Philips Semiconductors. The main purpose of this protocol is to provide easiness to connect peripheral chips with microcontroller. In embedded systems, all peripheral devices are connected as memory mapped devices to the microcontroller.

I2C necessitates two wires SDA (Serial Data Line) and SCL (Serial Clock Line) to carry information between devices. These two active wires are said to be bidirectional.

I2C protocol is a master to slave communication protocol. Each slave is been provided with unique address. In order to establish communication, master device initially sends the target slave address along with R/W (Read/Write) flag. The corresponding slave device will move into active mode leaving other devices in off state.

Once the slave device is ready, communication starts between master and slave devices. One bit acknowledgment is replied by the receiver if transmitter transmits 1 byte (8 bits) of data. A stop condition is issued at the end of communication between devices.

(Video) Advantages & Disadvantages of SPI Communication

Fig. 8 – Start and Stop Condition of I2C Communication Protocols

Advantages of I2C Communication Protocols

The advantages of I2C Communication Protocols are as follows:

  • Provides good communication between onboard devices which are accessed infrequently
  • Addressing mechanism eases master slave communication
  • Cost and circuit complexity does not end up on number of devices

Disadvantages of I2C Communication Protocols

The biggest disadvantage of I2C Communication Protocols is its limited speed.

Serial Peripheral Interface (SPI) Communication Protocols

SPI (Serial Peripheral Interface) is one of the serial communication protocol developed by Motorola. It is a 4-wire protocol namely MOSI (Master Out Slave In), MISO (Master In Slave Out, SS (Slave Select), and SCLK (Serial Clock).

As I2C protocol, SPI is also a master to slave communication protocol. In SPI, the master device first configures the clock at a particular frequency. Furthermore the SS line is used to select the appropriate slave by pulling the SS line low where it is normally held high.

The communication is established between the selected slave and the master device as soon as appropriate slave device is selected.

SPI is a full duplex communication protocol. SPI doesn’t limit data transfer to 8 bit words.

Fig. 9 – SPI Communication Protocols

Advantages of SPI Communication Protocols

The advantages of SPI Communication Protocol are as follows:

  • Faster than asynchronous serial communication protocol.
  • Support multiple slaves connectivity.
  • Universally accepted protocol and low cost.

Disadvantages of SPI Communication Protocol

The disadvantages of SPI Communication Protocol are as follows:

  • Requires more wires than other communication protocols.
  • Master device should control all slave communications (slave-slave communication is impossible).
  • Numerous slave devices leads to circuit complexity.

Controller Area Network (CAN) Communication Protocol

CAN (Controller Area Network) is a serial communication protocol developed by the Robert Bosch for intra vehicular communication. It requires two wires CAN High (H+) and CAN low (H-) for data transmission.

CAN protocol is based on a message oriented communication protocol.

Advantages of CAN Communication Protocols

The advantages of CAN Communication Protocols are as follows:

(Video) What are the Advantages & Disadvantages of LIN Protocol

  • Low cost and reliable
  • Shows robust performance
  • Secured and fast protocol

Disadvantages of CAN Communication Protocol

The disadvantages of CAN Communication Protocol are as follows:

  • Automotive oriented
  • Bit complex protocol
Also Read:


What is communication protocol and its types? ›

A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchronization of communication and possible error recovery methods.

What is the advantage of communication protocol? ›

They are required to exchange messages in or between computing systems. Communication protocols are important in telecommunications systems and other systems because they create consistency and universality for the sending and receiving of messages.

How many protocols are in embedded system? ›

In this series of articles, we will discuss the basics of the three most common protocols: SPI, I2C and UART. SPI, I2C, and UART are quite a bit slower than protocols like USB, Ethernet, Bluetooth, and Wi-Fi, but they're a lot simpler and use less hardware and system resources.

What are the 4 types of protocol? ›

Transmission Control Protocol (TCP) Internet Protocol (IP) User Datagram Protocol (UDP) Post office Protocol (POP)

What is the 3 types protocol? ›

There are three main types of network protocols. These include network management protocols, network communication protocols and network security protocols: Communication protocols include basic data communication tools like TCP/IP and HTTP.

What are the 4 types of communication? ›

There are four basic communication styles: passive, aggressive, passive-aggressive and assertive. It's important to understand each communication style, and why individuals use them.

What are the 7 types of communication? ›

Importance of Communication
  • Variety in Communication: Choose Wisely. We are lucky as humans to have a whole host of communication types available for us at our fingertips. ...
  • Interpersonal Communication. ...
  • Verbal Communication. ...
  • Nonverbal Communication. ...
  • Written Communication. ...
  • Visual Communication. ...
  • Listening.

CAN communication protocol advantages and disadvantages? ›

Advantages and disadvantages of CAN bus
High speed data rateLimited number of nodes (up to 64 nodes)
Low cost and light in weight and robustnessHigh cost for software development and maintenance
Supports auto retransmission for attribution lost messagesPossibility of signal integrity issues
4 more rows

What are the advantages of types of communication? ›

The message of non verbal communication reaches very fast and reduces the waste of time. Non verbal cues of communication like sign and symbols can be communicated quickly than written or oral messages. Helps illiterates people.

What are the 5 elements of protocol? ›

Network communication protocol requires following elements :
  • Message encoding : ...
  • Message formatting and encapsulation : ...
  • Message size : ...
  • Message timing : ...
  • Message delivery options :
22 Jul 2022

What are the types of embedded? ›

When classifying embedded systems based on the performance of microcontrollers, embedded systems are divided into three categories: Small-scale embedded systems. Medium-scale embedded systems. Sophisticated embedded systems.

What is communication protocol example? ›

A communications protocol is a set of formal rules describing how to transmit or exchange data, especially across a network. A standardised communications protocol is one that has been codified as a standard. Examples of these include WiFi, the Internet Protocol, and the Hypertext Transfer Protocol (HTTP).

What is a protocol Give 5 examples? ›

Among the most important sets of Internet protocols are TCP/IP (Transmission Control Protocol/Internet Protocol), HTTPS (Secure HyperText Transmission Protocol), SMTP (Simple Mail Transfer Protocol), and DNS (Domain Name System).

What are the 7 network protocols? ›

This layer uses following protocols: HTTP, SMTP, DHCP, FTP, Telnet, SNMP and SMPP.

Which Layer 4 protocol is used for a? ›

Telnet uses TCP at layer 4.

What is layer 3 protocol called? ›

The most significant protocol at layer 3 (also called the network layer) is the Internet Protocol, or IP. IP is the standard for routing packets across interconnected networks--hence, the name internet. It is an encapsulating protocol similar to the way Ethernet is an encapsulating protocol.

What are the 2 main protocols for the Internet? ›

Data needs to be broken up into small packets, which are then reassembled at the destination. The Transmission Control Protocol (TCP) is used to ensure reliable transport of those packets, with sequencing, acknowledgement, and retries. A faster but less reliable transport protocol is the User Datagram Protocol (UDP).

What are the 3 general types of communication? ›

When communication occurs, it typically happens in one of three ways: verbal, nonverbal and visual.

What are the 8 types of communication? ›

We identify 8 common types as:
  • Leadership and top-down comms (vertical communications)
  • Change communication.
  • Crisis communication.
  • Information comms.
  • Bottom-up or two-way communication.
  • Peer communication (horizontal communications)
  • Culture comms.
  • Campaign comms.
12 Jul 2019

What are the 8 types of communication process? ›

The communication process involves understanding, sharing, and meaning, and it consists of eight essential elements: source, message, channel, receiver, feedback, environment, context, and interference.

What are 2 types of communication? ›

Communication can be categorized into three basic types: (1) verbal communication, in which you listen to a person to understand their meaning; (2) written communication, in which you read their meaning; and (3) nonverbal communication, in which you observe a person and infer meaning.

What are the 5 importance of communication? ›

Importance of Communication
  • The Basis of Co-ordination. ...
  • Fluent Working. ...
  • The Basis of Decision Making. ...
  • Increases Managerial Efficiency. ...
  • Increases Cooperation and Organizational Peace. ...
  • Boosts Morale of the Employees.

What are six types of communication? ›

What are the 6 types of communication? The six types of communication are oral, interpersonal, nonverbal, written, visual, and listening. Oral includes any spoken speech and interpersonal involves verbal and nonverbal communication.

What is protocol and its advantages? ›

Protocols provide us with a medium and set of rules to establish communication between different devices for the exchange of data and other services. Protocols are needed in every field like society, science & technology, Data Communication, media, etc.

What are the advantages and disadvantages of communication technologies? ›

able to communicate from anywhere in the world. long distance communication is easier.
Disadvantages of Communication Technology:
  • harder to use for people of older generations.
  • cyber-bullying and cyber-skyping made possible.
  • not always reliable.
  • makes communciation less personal.
  • not always sure who you are communicating with.
28 Feb 2012

What is the advantage and disadvantages? ›

As nouns, the difference between disadvantage and advantage is that disadvantage is a weakness or undesirable characteristic; a con while the advantage is any condition, circumstance, opportunity, or means, particularly favorable to success, or any desired end.

What are the 4 importance of communication? ›

This article throws light on the thirteen major importance's of communication in management, i.e, (1) Basis of Decision-Making and Planning, (2) Smooth and Efficient Working of an Organisation, (3) Facilitates Co-Ordination, (4) Increases Managerial Efficiency, (5) Promotes Co-operation and Industrial Peace, (6) Helps ...

How many types of protocols are they and give examples? ›

Generally speaking, there are three types of protocols in networking -- communication, such as Ethernet; management, such as Simple Mail Transfer Protocol (SMTP); and security, such as Secure Shell, or SSH.

What is a Layer 5 protocol? ›

Layer 5 of the OSI Model: Session Layer is the layer of the ISO Open Systems Interconnection (OSI) model that controls the dialogues (connections) between computers. It establishes, manages, and terminates the connections between the local and remote application.

What are 2 embedded systems? ›

Examples of embedded systems include:
  • central heating systems.
  • engine management systems in vehicles.
  • domestic appliances, such as dishwashers, TVs and digital phones.
  • digital watches.
  • electronic calculators.
  • GPS systems.
  • fitness trackers.

Why we use embedded system? ›

The purpose of embedded systems is to control a specific function within a device. They are usually designed to only perform this function repeatedly, but more developed embedded systems can control entire operating systems.

What are three types of embedded system? ›

Based on Performance and Functional Requirements it is divided into 4 types as follows :
  • Real-Time Embedded Systems : ...
  • Stand Alone Embedded Systems : ...
  • Networked Embedded Systems : ...
  • Mobile Embedded Systems :
21 Aug 2020

What is embedded system protocol? ›

The Intra system protocol establishes communication between components within the circuit board. In embedded systems, intra system protocol increases the number of components connected to the controllers. On device communication protocols are known as intra system communication protocols.

What are the four types of embedded systems? ›

When classifying embedded systems based on performance and functional requirements, embedded systems are divided into four categories:
  • Real-time embedded systems.
  • Standalone embedded systems.
  • Network, or networked, embedded systems.
  • Mobile embedded systems.
22 Jul 2021

What are the 4 main types of communication? ›

There are four basic communication styles: passive, aggressive, passive-aggressive and assertive. It's important to understand each communication style, and why individuals use them.

What are the 3 main types of communication? ›

When communication occurs, it typically happens in one of three ways: verbal, nonverbal and visual.

What are the types of embedded system? ›

Types of Embedded Systems
  • Stand-alone Embedded Systems. ...
  • Real-time Embedded Systems. ...
  • Network Embedded Systems. ...
  • Mobile Embedded Systems.

What is communication in embedded system? ›

The majority of embedded communication systems can be classified as either point-to-point networks (data links) or shared media networks (data highways). It is important to understand the trade-off between these two types of systems. In point-to-point networks, each node of the system is connected to every other node.

Which is the fastest communication protocol? ›

SPI speed, the fastest communication protocol for sending data over short distances from the two protocols is SPI. SPI protocol is best suited for low-power applications requiring high speed. The high-speed signals of an SPI interface limit its data transfer only over short distances.

What are the disadvantages of embedded systems? ›

Disadvantages of Embedded System :
  • Subsequent to creating installed framework, you can't make any alteration, improvement or up degree.
  • Hard to keep up.
  • Hard to take a back-up of implanted documents.
  • You need to reset all setting, due to happen any issue in the framework.
  • Investigating is Harder.
28 Dec 2020

What are the two communication protocols? ›

The most important protocols for data transmission across the Internet are TCP (Transmission Control Protocol) and IP (Internet Protocol). Using these jointly (TCP/IP), we can link devices that access the network; some other communication protocols associated with the Internet are POP, SMTP and HTTP.


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