geheugenbeheersunit

The geheugenbeheersunit, commonly abbreviated as **MMU** (Memory Management Unit), is a specialized hardware component in a computer system responsible for managing virtual memory and translating virtual addresses to physical addresses. It plays a crucial role in modern operating systems by enabling efficient memory allocation, protection, and isolation between processes.

The MMU operates by converting virtual addresses—used by software—to physical addresses, which the CPU can directly access. This process involves a translation lookup table, often referred to as a **page table**, stored in memory. The MMU handles page faults, which occur when a process accesses a virtual address that is not currently mapped to physical memory. In such cases, the operating system loads the required data from disk into RAM, updating the page table accordingly.

Key functions of the MMU include memory protection, ensuring that processes cannot access or modify memory outside their allocated space, and support for features like paging and segmentation. Paging divides memory into fixed-size blocks called pages, allowing for better memory utilization and swapping unused pages to disk. Segmentation, on the other hand, divides memory into variable-sized segments, useful for managing different types of data structures.

The MMU also facilitates memory sharing between processes, enabling efficient resource utilization and inter-process communication. Additionally, it supports advanced features such as memory-mapped I/O, where input/output devices are accessed via memory addresses, simplifying hardware interaction.

Modern CPUs integrate the MMU as part of their architecture, working in tandem with the operating system to provide a seamless and secure memory management framework. Without the MMU, virtual memory and process isolation would not be feasible, making it an essential component in contemporary computing systems.