Non-contiguous allocation based on paging techniques, often implemented in a sub

Question

Non-contiguous allocation based on paging techniques, often implemented in a sub-system called the Memory Management Unit (MMU), allows dynamic allocation of small memory partitions called frames into which disk pages are loaded. The main task of the MMU is to translate logical addresses (of processes) to the corresponding physical addresses. Given a process that has a logical address of 12242, and addressable disk space of 16MB and addressable RAM space of 1MB; answer the following questions:

Assume that each page is 1KB, how many bits of the logical address will be used to point to the process’s page table?   ________________

How many frames would be available in RAM? _____________

Assuming there are 8 frames that are frequently used and the MMU supports a set of associative registers or lookaside buffer, sketch a full diagram to illustrate how the MMU performs its logical-to-physical address translation given a logical address of 12242, page size of 1KB, and an allocation of frame number 200 for this page.

Explanation / Answer

Given that page size is 1KB or 2^10 bytes so 10 bits are required to represent offset within the page and we know that logical address is the address of the disk and given that size of the disk is 16 MB or 2^24 bytes so 24 bits are required to represent logical address and we also know that

number of bits for page number + offset within the page=number of bits in the logical address space
number of bits for page number +10=24

number of bits for page number =14

now for second part we know that

number of bits to represent frame + offset within the page =number of bits to represent physical address space

number of bits to represent frame +10=20 (since physical address space is 1MB or 2^20 bytes)

number of bits to represent frame =10

so total number of frames =2^10

=1024 frames

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.