How does a Memory Protection Unit (MPU) work and how do you configure it?

MPU enforces memory access rules to detect software errors and provide isolation. Configuration defines regions with: Base address, Size (power of 2, min 32 bytes in Cortex-M), Access permissions (privileged/unprivileged, read/write/execute), Memory attributes (cacheable, shareable, device). ARMv8-M MPU uses separate configuration for Secure and Non-Secure. Configuration steps: Define regions for code, data, stack, peripherals; Enable MPU; Faults trigger MemManage exception for error handling. Use cases: Stack overflow detection, preventing code execution from RAM, isolating RTOS tasks, and protecting critical data.