ES

DEF - IT IS A SPECIALISED COMPUTING SYSTEM THAT THAT IS DESIGNED FOR A DEDICATED

FUNCTION OR SET OF FUNCTIONS IN A LARGER SYSTEM.

It consists of a microcontroller or microprocessor, along with memory, input/output interfaces,

and software, all integrated into hardware.

It has major 3 components:

1. Hardware (The Physical Parts)

This is everything you can touch in an embedded system. It includes:

• Processor (Microcontroller or Microprocessor) – The brain that processes information

and makes decisions.

• Memory (RAM, ROM, Flash) – RAM is like short-term memory (stores temporary data),
while ROM/Flash stores permanent instructions (software).

• Input Devices – Sensors, buttons, or touchscreens that take in information (e.g., a

temperature sensor in an AC).
 • Output Devices – Screens, LEDs, motors, or speakers that show results or perform actions
(e.g., a microwave display or speaker in a smartwatch).

• Power Supply – Provides electricity (battery or adapter).

2. Software (Firmware – The Brain’s Instructions)

• This is the program or code written to control the hardware.

• It tells the embedded system what to do and how to react to inputs.

• Stored in ROM or Flash memory so it stays even when power is off.

• Example: In a washing machine, software controls washing cycles based on user selection.

3. Real-Time Operating System (RTOS) [If Needed]

• Not all embedded systems need an OS, but complex ones do (like in cars or medical
devices).

• RTOS helps manage multiple tasks ef ciently, ensuring real-time responses.

• Example: In an airbag system, the RTOS ensures the airbag deploys instantly during a
crash.

• Supervises

• Scheduling

• Inter task communication

• Resources sharing

• Memory allocation

Characteristics of es :

1. Dedicated Functionality – Designed for a speci c task (e.g., washing machine control, traf c
light system).

2. Real-Time Operation – Often works with real-time constraints to ensure quick and accurate
responses.
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3. Microcontroller/Microprocessor-Based – Uses a microcontroller (MCU) or microprocessor
(MPU) as the main processing unit.

4. Cost-Effective – Designed to be low-cost while maintaining performance.

5. Real-Time Communication – Uses protocols like UART, SPI, I2C, or CAN for data exchange
with other devices.

6. High Reliability & Stability – Designed to run continuously without crashes or failures.

7. Compact Size – Small and lightweight, as they integrate multiple components on a single chip.

8. Low Power Consumption

9. Limited User Interface – May have a minimal or no direct user interface (e.g., sensors and
actuators instead of keyboards).

10. Memory Constraints – Limited RAM, ROM, and storage, optimized for ef ciency

CONTRAINTS

1. Scalability Limitations – Hard to upgrade or modify once deployed

2.Cost Constraints – Designed to be low-cost, limiting hardware choices and features.

3.Cost Constraints – Designed to be low-cost, limiting hardware choices and features.

4. Processing Power – Uses microcontrollers or microprocessors with lower clock speeds

compared to general-purpose computers.

5. Limited User Interface – Often lacks a full display, keyboard, or advanced interaction options.

ADVANTAGES :

1. SMALL SIZE

2. FASTER TO LOAD

3. EASY TO MANAGE
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 4. LOQ COST

5. USES LESS RESOURCES LIKE MEMORY AND MICROPROCESSOR

DISADVANTAGES :

1. HARDWARE IS LIMITED

2. DIFFCULT TO UPGRADE

3. IF ANY PROBLEM OCCURS THEN YOU NEED TO RESET SETTINGS

4. TROUBLESHOOTING IS DIFFICULT

Troubleshooting is the process of identifying, diagnosing, and xing problems in a system, device,
or software.

CLASSIFICATION

Embedded systems can be classi ed based on performance, real-time constraints, and

functionality.

1. Classi cation Based on Performance & Complexity

1.1 Small-Scale Embedded Systems

• Uses an 8-bit or 16-bit microcontroller.

• Has limited RAM and ROM.

• Performs simple, dedicated tasks.

• Low power consumption.

• C LANGUAGE IS USED

• IT IS BATTERY OPERATED

• IT HAS LITTLE HARDWARE AND SOFTWARE COMPLEXITIES

• INVOLVES BOARD LEVEL DESIGN

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 PROGRAMMING TOOLS:

EDITOR , ASSEMBLER, CROSS ASSEMBLER

EXAMPLE :

DIGITAL WATCHES , CALCULATORS

1.2 Medium-Scale Embedded Systems

* Uses a 16-bit or 32-bit microcontroller/microprocessor.

* Both hardware and software are complex
* Faster than the small -scale embedded systems
* Runs simple real-time operating systems (RTOS).

Lang ; c , c++ , java , rots, debugger, ide

Ex : routers for networking , cameras, smartphones

1.3 Large-Scale Embedded Systems

also known as sophisticated embedded systems
1.Uses a 32-bit or 64-bit microprocessor (often with multiple cores).
2.Runs advanced real-time OS (RTOS)
3.Requires high-speed processing and large memory.
4. Hardware and software complexity is very large
5. Performs large scale complex functions

Tool: may not be easily available for reasonable cost

Ex : washing machines and security products

2. Classi cation Based on Real-Time Requirements

2.1 Hard Real-Time Embedded Systems

De nition:

• Systems that must meet strict timing deadlines.

• Failure to respond within the deadline can cause system failure or disaster.
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 Characteristics:
The system always responds in a xed, predictable time. It never delays beyond the set limit.
• Used in safety-critical applications.

• Examples:

◦ Airbag systems (must deploy in milliseconds).

◦ Pacemakers (must regulate heartbeat precisely).

◦ Missile guidance systems (must respond instantly to target changes).

2.2 Soft Real-Time Embedded Systems

• De nition:

◦ Systems where timing is important but occasional delays are acceptable.

◦ Performance degrades if deadlines are missed, but the system continues functioning.

‘Characteristics:

• Allows slight variations in response time.

• Used in multimedia and entertainment applications.

Examples:

• Video streaming systems (slight delay in buffering is acceptable).

• Online gaming (minor network delays are tolerable).

• Voice over IP (VoIP) (small lags in voice transmission are manageable).

2.3 Firm Real-Time Embedded Systems

• De nition:

◦ A mix between hard and soft real-time systems.

◦ Missing a deadline does not cause system failure, but it reduces output quality.

• Characteristics:

◦ Should meet most deadlines, but minor misses are allowed.

◦ Used in industrial and scienti c applications.

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 Examples:
Traf c light control systems (timing is important, but slight delays are manageable).

Banking transaction systems (slight delays in processing are acceptable but not ideal).

3. Classi cation Based on Functionality

3.1 Standalone Embedded Systems

The type of es which doesn’t require any system , work on its own

* uiless complex
* Work on its own
* Independent to any system
* Performs dedicated tasked autonomously
* Doesn’t require internet connection

Ex - digital cam
Ovens
Automatic washing machines

3.2 Networked Embedded Systems

• De nition:

◦ Embedded systems that communicate with other devices via a network (LAN,
WAN, or Internet).

Characteristics:

• Uses communication protocols like Wi-Fi, Bluetooth, Zigbee, or Ethernet.

• Often part of the Internet of Things (IoT)

• Examples:

◦ Smart home devices (Alexa, Google Nest).

◦ Smart meters (monitor and transmit energy usage to power companies).

◦ Security surveillance systems (IP cameras that stream video over the internet).

3.3 Mobile Embedded Systems

• De nition:
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 ◦ Portable, battery-powered embedded systems designed for mobility.

Characteristics:

• Energy-ef cient and lightweight.

• Works with sensors and wireless communication.

• Examples:

◦ Smartphones (Android, iOS devices).

◦ GPS devices (navigation and tracking systems).

◦ Wearable tness trackers (smartwatches, heart rate monitors).

processor embedded into a system

An embedded processor is a small computer chip that is built into a system to control its
functions. Unlike general-purpose processors (used in PCs and laptops), embedded processors are
designed for speci c tasks and are part of larger electronic systems like washing machines, cars,
or smartphones.

Types of Embedded Processors

Processors are divided into 4 types . Int that 1st is general purpose processor
which is further divided into 5 types .

1. General purpose processor :

* This processors are designed for general purpose ie to handle multiple taskeds
and not any speci c task. Commonly used for laptops, computers and servers.

* Programed by user, can run multiple applications at the same time.

* It can be replaced or upgraded for better performance.

* It has high computing power, as it is designed for complex operations like ai,
data processing
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* It supports large capacity memory like ram and storage.

* It is versatile and can be used in different elds like gaming, programming and
business applications

* Not suitable for real time applications

Its types :

1. Microprocessor

It has a single vlci chip having cpu that executes the instructions and processes
data. It requires external memory(ram,rom) and I/O devices to work.
used in pcs, laptops and servers

Key Features:
✅ Fast processing power.
✅ Supports multitasking (running multiple applications).
✅ Needs external components like RAM and storage.
🔹 Examples:

• Intel: i3, i5, i7, i9

• Arm - based cortex - a series (tabs and mobile)

2. Microcontroller (MCU – Small Computer on a Chip)

🔹 What is it?

• A mini-computer inside a single chip.

• Includes CPU, RAM, ROM, and I/O ports in one unit.

Designed for speci c tasks like controlling machines or sensors.

🔹 Key Features:
✅ Low power consumption.
✅ Designed for real-time control tasks.
✅ Cost-effective and ef cient.
Examples: Intel 8051, ARM Cortex-M series. Where is it used?🚗 Cars, washing
machines, traf c lights, medical devices.
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 3. Digital Signal Processor (DSP – High-Speed Math Processor)
🔹 What is it?

• A processor optimized for mathematical calculations and real-time data processing.

• Used in audio, video, and communication systems.

🔹 Key Features:
✅ Processes signals (audio, video, radar) quickly.
✅ Optimized for real-time applications.
✅ Handles complex mathematical functions.

Ex - SHARC DSP (Analog Devices)

Where is it used?
🎵 Audio processing, speech recognition, mobile communication, radar systems.

4. Graphics Processing Unit (GPU – Graphics & AI Processor)

🔹 What is it?

• A processor designed for graphics rendering and parallel processing.

• Used in gaming, AI, and machine learning.

🔹 Key Features:
✅ Handles complex graphics (3D rendering, gaming).
✅ Processes large amounts of data in parallel.
✅ Used for AI, deep learning, and cryptocurrency mining.

🔹 Examples:
• NVIDIA Tesla, Google TPU (AI & Deep Learning)

Where is it used?
🎮 Gaming consoles, AI research, crypto mining

Application-Speci c Standard Processor (ASSP)

An Application-Speci c Standard Processor (ASSP) is a type of processor designed for a

speci c function but is not fully customizable like an ASIC (Application-Speci c Integrated
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 Circuit). It is used in devices that need high performance for a speci c application, such as
multimedia processing, networking,

Key Features of ASSP

✅ Optimized for a speci c application (e.g., audio processing, networking).

✅ Faster than general-purpose processors for that particular task.
✅ More exible than ASICs because they can be reused in different products.
✅ Lower power consumption compared to general processors.

Examples of ASSP :
Audio/video asap -Used in MP3 players, set-top boxes
Networking asap -, Used in routers and switches.

Where is ASSP Used?

• Multimedia devices (TVs, cameras, gaming consoles)

• Communication systems (Wi-Fi routers, modems)

Application-Speci c Instruction-Set Processor (ASIP)

An Application-Speci c Instruction-Set Processor (ASIP) is a processor designed for a speci c
type of application but allows some programmability. It is a balance between a general-purpose
processor (GPP) and a custom ASIC (Application-Speci c Integrated Circuit).

SIPs are used in applications that need high performance, power ef ciency, and exibility, such
as AI, signal processing, and networking.
✅ Lower power consumption compared to general-purpose processors.
✅ Used in AI, robotics, image processing, and communication systems.

Examples of ASIP

🧠 AI Processors – Google TPU

🎵 Audio Processors – Dolby Audio

Where is ASIP Used? Self-driving car technology), Camera processors), 4G/5G modems
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 Role of Processors in Embedded Systems (7)

A processor is the brain of an embedded system. It is responsible for executing instructions,

processing data, and controlling hardware components. The ef ciency and capabilities of an
embedded system depend largely on the processor used.

1. Processing Data
🔹 The processor fetches, decodes, and executes instructions.

🔹 Performs arithmetic and logical operations to process input data.

🔹 Example: In a washing machine, the processor calculates the required wash cycle based on the
load and fabric type.

2. Controlling Devices (Peripherals & Sensors)

🔹 The processor manages input and output devices like sensors, motors, displays, and
communication modules.
🔹 It reads sensor data and makes real-time decisions.
🔹 Example: In a smart AC, the processor adjusts cooling based on temperature sensor readings.

3. Communication (Internal & External)

🔹 Internal Communication – The processor interacts with memory (RAM, ROM) and storage.
🔹 External Communication – It connects with other systems via protocols like UART, I2C, SPI,
CAN, etc.

Example: In a car’s ECU, the processor communicates with multiple sensors (speed, fuel,
temperature) to optimize engine performance.

4. Power Ef ciency
Embedded processors are designed for low power consumption to increase battery life.
🔹 Example: In IoT devices, the processor enters a low-power sleep mode when idle to conserve
energy.

5. Real-Time Processing
Some embedded systems require real-time response with minimal delay.
🔹 Real-Time Operating Systems (RTOS) help processors manage time-sensitive tasks
ef ciently.
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🔹 Example: In airbag systems, the processor must detect a crash and deploy the airbag within
milliseconds

6. Security & Error Handling

Embedded processors implement encryption to protect sensitive data.
🔹 Error detection & correction mechanisms ensure system reliability.
In medical devices (like pacemakers), processors use error-checking algorithms to prevent failures.

7. Customization & Optimization

🔹 Embedded processors can be customized for speci c applications.

The processor selection depends on multiple factors like performance, power ef ciency, cost, size,
compatibility, real-time processing, and security. Choosing the right processor ensures optimal
performance, ef ciency, and reliability for an embedded system.

Embedded Hardware Units and Devices in a System

An embedded system consists of both hardware and software components. The hardware
includes various units and devices that work together to perform a speci c function.

These hardware components ensure the system operates ef ciently, meets real-time constraints, and
interacts with the environment.

Major Hardware Components in an Embedded System

An embedded system consists of the following key hardware units:

1⃣ Processor (Microprocessor / Microcontroller)

2⃣ Memory (RAM, ROM, Flash, EEPROM)
3⃣ Input Devices (Sensors, Keyboards, Switches, etc.)
4⃣ Output Devices (LCDs, LEDs, Buzzers, etc.)
5⃣ Communication Interfaces (UART, SPI, I2C, CAN, etc.)
6⃣ Timers & Counters (For real-time operations)
7⃣ Power Supply (Battery, Voltage Regulators, etc.)
8⃣ Special Purpose Hardware (DSP, FPGA, ASIC, etc.)
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1⃣ Processor (Microprocessor / Microcontroller)
✅ The brain of the embedded system that processes data and executes instructions
✅ Can be Microprocessors (MPU) or Microcontrollers (MCU).
✅ Example:
• Microcontroller (MCU): Used in washing machines (e.g., 8051, PIC, AVR, ARM Cortex-
M).

• Microprocessor (MPU): Used in advanced systems like industrial automation (Intel, ARM
Cortex-A).

2⃣ Memory (RAM, ROM, Flash, EEPROM)

Stores program code, temporary data, and system states.
Types:
• RAM (Random Access Memory): Temporary storage for quick access. Example: DDR
RAM.

• ROM (Read-Only Memory): Stores rmware. Example: EEPROM, Flash ROM.

• Flash Memory: Used for non-volatile storage. Example: SD card in IoT devices.
✅ Example:

• Smartphone: Uses RAM for temporary data storage and Flash memory for permanent
storage.

3⃣ Input Devices (Sensors, Switches, Keypads)

✅ These devices capture data from the external environment.
✅ Types:

• Sensors: Measure temperature, pressure, motion, etc. (Examples: Temperature sensor

(DHT11), Proximity sensor (IR)).

• Switches & Buttons: Used in home appliances (e.g., washing machine controls).

• Keypads: Found in ATMs, security systems.

4⃣ Output Devices (LEDs, LCDs, Buzzers, Motors)

✅ Output devices provide feedback or take action based on processor instructions.
✅ Types:

• LEDs & LCD Displays: Used for visual output (e.g., 7-segment display in digital clocks).
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 • Buzzers & Speakers: Used for alarms and noti cations (e.g., microwave oven beep
sound).

5⃣ Communication Interfaces (UART, SPI, I2C, CAN, USB, Ethernet)

✅ Used for data exchange between different devices and systems.

✅ Types:

• UART (Universal Asynchronous Receiver-Transmitter): Used in serial communication

(e.g., Bluetooth module HC-05).

• I2C (Inter-Integrated Circuit): Used in multi-device communication (e.g., RTC module in

smartwatches).

• SPI (Serial Peripheral Interface): Used for fast communication (e.g., SD card reader).

• CAN (Controller Area Network): Used in automotive systems for real-time data exchange.

• USB, Ethernet, WiFi, Bluetooth: Used in IoT and smart devices.

6⃣ Timers & Counters (Real-Time Operations)

✅ Used to measure time intervals and count events for scheduling tasks.
✅ Examples:

• Real-Time Clock (RTC): Used in digital watches to track time.

• Timer in a microwave oven: Controls cooking duration.

7⃣ Power Supply (Battery, Voltage Regulators, SMPS)

✅ Supplies power to all components of the embedded system.

8⃣ Special Purpose Hardware (DSP, FPGA, ASIC)

✅ Some embedded systems require customized or high-speed hardware

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embedded software in the system

to make the hardware work, we write the software.

embedded software - it is a program that controls the embedded system.

program is the piece of code, that is written to perform a task.

Embedded software is loaded in the micro-controller which takes care of all the operations
performed in the embedded system

tools required to develop this embedded software :

* editor - to write the program

* Compiler - to compile the code

* Assembler - to convert high level code to low - level code

* Debugger- to debug the code

different types of embedded software -

* Watches, phones, toasters

guides the missiles
controls the satellites
used in medical instruments

software complexity

* It runs on 8 bit micro controller with just few kilo bytes of memory .

* Complex embedded softwares are used in aircrafts , missile guidance systems and navigation
system

requirements :

* Reliability - s/w must be reliable Fault Tolerance – Should continue working even in case of
minor failures.

🔹 Error Handling – Must detect and recover from software or hardware errors.
 🔹 Security Features – Protect against unauthorized access and cyber threats.

Maintainability & Scalability

Code should be easy to update or modify.Software should be adaptable to future hardware
upgrades.

1⃣ Performance Requirements
he software should process inputs quickly.
Uses minimal CPU power and memory.
Software should reduce battery consumption

1. Functional Requirements
The software should perform only the required function
Must respond within a xed time
Read and process data from sensors accurately.
Should support UART, SPI, I2C, CAN, TCP/IP, etc.

Embedded Software Development Process (6)

Step 1: Requirement Analysis – De ne software functions

Step 2: System Design – Choose OS and communication interfaces.
Step 3: Coding – Write software using C, C++, Python, or Assembly
Step 4: Compilation & Debugging – Use IDE
Step 5: Testing – Test using simulators and real hardware.
Step 6: Deployment & Maintenance – Install on the device and update as needed.

Components of Embedded Software

Embedded software consists of multiple layers, each responsible for different functions.
1. Bootloader
✅ The rst program that runs when the device is powered on.
✅ Initializes hardware and loads the main software.
✅ Example: BIOS in computers, bootloader in smartphones.
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2. Operating System (RTOS or Bare-Metal)
✅ Manages tasks, memory, and I/O operations.
✅ Can be:

• Bare-Metal System (No OS) → Simple devices (e.g., washing machines).

• RTOS (Real-Time OS) → Ensures fast response time (e.g., industrial robots).
✅ Examples: FreeRTOS, VxWorks, QNX.

3. Device Drivers
✅ Software that controls hardware components like sensors, actuators, displays, etc.
✅ Acts as a bridge between the OS and hardware.
✅ Example:

• A WiFi driver allows a device to connect to the internet.

• A USB driver enables communication with external devices.

•
4. Middleware & Protocol Stacks

✅ Middleware provides communication between software components.

✅ Includes communication protocols like:

• TCP/IP, Bluetooth, Zigbee (for networking).

• UART, SPI, I2C, CAN (for hardware communication).

5. Application Software
The main program that executes the system’s functionality.

6. Embedded Libraries & Security Modules

✅ Provides pre-written functions for tasks like image processing, encryption, and AI.
✅ Security modules ensure data protection and prevent unauthorized access.
 Design Process of Embedded System (9)
The design process of an embedded system involves multiple steps to develop a reliable, ef cient,
and real-time system
The design process of an embedded system involves multiple steps to develop a reliable, ef cient,
and real-time system

1. Requirement Analysis
✅ De ne the system’s purpose, constraints, and performance needs.
✅ Identify hardware and software requirements.
✅ Example: In a smartwatch, requirements include low power consumption, real-time heart
rate monitoring, and Bluetooth connectivity.

2. System Speci cation & Architecture Design

✅ Design block diagrams for system components (processor, memory, I/O, communication
interfaces).
✅ Choose microcontroller/microprocessor, sensors, actuators, and storage devices.

3. Hardware & Software Partitioning

✅ Decide which functions should be implemented in hardware and which in software

4. Operating System Selection

✅ Choose RTOS (Real-Time OS) or Bare-Metal programming.
✅ RTOS is used if real-time task scheduling is required.

5. Coding & Firmware Development

✅ Write embedded software using C, C++, Python, or Assembly.
✅ Optimize memory usage, power consumption, and execution speed.
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6. Hardware Testing & Simulation
✅ Test each hardware component before integrating software.

✅ Use simulation tools like MATLAB to verify design

7. Software Testing & Debugging

✅ Debug code using debugging tools, and simulators.
✅ Perform unit testing, integration testing, and stress testing.

8. Integration & System Testing

✅ Combine hardware and software to test real-world performance.
✅ Ensure the system meets functional and non-functional requirements.

9. Deployment & Maintenance

✅ Install the embedded system in real-world applications.
✅ Provide rmware updates and maintenance for better performance.

characteristics and quality attributes of an embedded system

Characteristics - Fundamental features of an embedded system that de ne its structure and behavior. Its concern is How the
system is built and functions
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Quality - Performance-related factors that determine how well the system functions. It is concerned with How ef cient and
reliable the system is.

Characteristics of Embedded Systems

1⃣ Real-Time Operation
✅ Must respond to inputs within a xed time

2⃣ Dedicated Functionality

✅ Designed for a speci c task

3⃣ Power Ef ciency

✅ Uses low power for battery-operated devices.

5⃣ Reliability & Safety

✅ Must work continuously without failure.

7⃣ Small & Compact Size

✅ Designed to be lightweight and space-ef cient.

8⃣ Communication Capability

✅ Can exchange data with other systems via protocols like UART, SPI, I2C, CAN, Bluetooth,
WiFi.
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 Quality Attributes of Embedded Systems

1⃣ Performance

✅ Should process tasks quickly and ef ciently.

2⃣ Ef ciency

✅ Should consume minimum power, memory, and processing resources.

3⃣ Reliability

✅ Should function continuously without failure.

7⃣ Scalability

✅ Should allow hardware or software upgrades for future improvements.

6⃣ Real-Time Responsiveness

✅ Must respond to events within a de ned time limit.

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