Which component is primarily responsible for translating logical addresses to physical addresses in a paging system?

• A. Disk controller
• B. On-Chip network controller
• C. Memory Management Unit (MMU) and page tables
• D. CPU

Answer: (C)

In paging, the actual translation from a virtual (logical) address to a physical address is handled by the Memory Management Unit (MMU) using the page tables. The CPU generates a virtual address, which is split into a page number and an offset. The MMU consults the page table to find the corresponding physical frame number for that page, then combines it with the offset to form the physical address. A fast path for this translation is the Translation Lookaside Buffer (TLB), which caches recent mappings to speed up repeated translations. If the page isn’t in memory, a page fault occurs and the operating system brings the page into RAM, updating the page table accordingly.

The other components don’t perform this translation. A disk controller handles data transfer to and from storage, not address translation. An on-chip network controller manages network communication, not memory address mapping. The CPU executes instructions and generates addresses, but the actual mapping from virtual to physical addresses is performed by the MMU with the help of the page tables.