Memory-Mapped I/O
Memory-Mapped I/O (MMIO) is a technique where input/output (I/O) device registers are mapped into the memory address space of a computer system, allowing the CPU to access them using standard memory read/write instructions instead of specialized I/O instructions. This approach simplifies programming by treating I/O operations similarly to memory accesses, enabling direct manipulation of hardware through memory addresses. It is commonly used in modern computer architectures, such as x86 and ARM, for interfacing with peripherals like graphics cards, network interfaces, and storage controllers.
Developers should learn Memory-Mapped I/O when working on low-level systems programming, embedded systems, or operating system development, as it provides a unified and efficient way to control hardware devices without the overhead of separate I/O instructions. It is particularly useful in scenarios requiring high-performance I/O, such as real-time applications, device drivers, or when optimizing for minimal latency in hardware interactions. Understanding MMIO is essential for debugging hardware issues, writing firmware, or implementing custom peripherals in microcontrollers and system-on-chip (SoC) designs.