Low-level C with volatile, bit-masks and registers.
Embedded C relies on fixed-width types (uint8_t), bit masks (set a bit with reg = reg OR (1<<n)), volatile for hardware registers, const for flash data and careful memory use. Avoid dynamic allocation, recursion and unbounded loops. MISRA C guides safety-critical code.
Toggle a pin: GPIOA->ODR ^= (1<<5).
Embedded C is the main language for firmware, and writing it correctly means understanding volatile, registers and bit operations.
Low-level C with volatile, bit-masks and registers.
Embedded C is the main language for firmware, and writing it correctly means understanding volatile, registers and bit operations.
It tells the compiler that a value can change outside the normal flow of code, such as by a register or an interrupt, so each access must be made.
They change single bits without disturbing others, which is essential when a register holds several control fields.
Typical applications include writing a driver that reads a status register safely, setting or clearing a single bit in a control register with masks and declaring a variable that an interrupt changes so the compiler does not optimise it away.
Study "DMA" first (topic 70 of 104 in Electronics & Embedded). It covers the groundwork this topic builds on.
Volatile prevents optimisation. Structs map registers. Interrupt-safe variables.
Toggle a pin: GPIOA->ODR ^= (1<<5).
The next topic is "Memory-mapped I/O", which builds directly on this one.
It is classed as Advanced in Electronics & Embedded (topic 71 of 104). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Electronics & Embedded.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.