Memory management unit hardware, Treat addressing
The main role is to convert the virtual address to a physical address for use in the memory system (TLB). It responsible to allow to access to physical memory.
MMU enforces hardware enforcement to isolate memory address block and it produce segmentation fault when the process try to access not allowed block.
Memory management unit
A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit that examines all memory references on the memory bus, translating these requests, known as virtual memory addresses, into physical addresses in main memory.
https://en.wikipedia.org/wiki/Memory_management_unit

Seonglae Cho