What is embedded?
- C++ course
- Expert
- Lesson 31/47
- 5 min
Learn the embedded system concept and C++ constraints.
What is embedded?
An embedded system is a computer designed for a specific task, with limited memory and power. A washing machine, a car engine control unit, a smart watch are all embedded systems.
Embedded C++ programs typically run without an operating system (bare-metal) or on an RTOS (Real-Time Operating System). Memory is very tight; tools that use dynamic memory like std::vector are avoided. Hardware is accessed directly through memory-mapped I/O.
Constraints and tools
In embedded systems dynamic memory allocation is constrained; the heap is small or absent. Large data is kept static or on the stack. Exception handling is usually disabled (-fno-exceptions); exception tables take memory.
Hardware access happens through memory-mapped I/O: writing to a specific memory address changes a register. These addresses are read/written as volatile pointers; this prevents the compiler from skipping reads. An RTOS handles task scheduling; bare-metal programs manage their own loop.
Practice Write an embedded-style message
In main write std::cout << "Embedded"; and end with return 0;.
Starter code
#include <iostream>
int main() {
// Print the message
return 0;
}Sample solution
#include <iostream>
int main() {
std::cout << "Embedded";
return 0;
}Expected output
Embedded
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What characterizes an embedded system?
// program running on a microcontroller- Unlimited memory
- General-purpose operating system
- Designed for a specific task, constrained resources Correct answer
- Always a powerful CPU
Explanation: An embedded system is designed for a specific task with constrained resources.
2 Complete the main name
int ____(void) { /* embedded entry */ }int main(void) { /* embedded entry */ }Explanation: main is the program entry point.
3 Match each concept to its role
| Term | Meaning |
|---|---|
RTOS |
Real-time kernel |
MMIO |
Memory-mapped I/O |
volatile |
Hardware access |
interrupt |
Hardware interrupt |