GATEverse — GATE CSE previous year questions

A certain computer system has the segmented paging architecture for virtual memory. The memory is byte addressable. Both virtual and physical address spaces contain $2^{16}$ bytes each. The virtual address space is divided into $8$ non-overlapping equal size segments. The memory management unit (MMU) has a hardware segment table, each entry of which contains the physical address of the page table for the segment. Page tables are stored in the main memory and consists of $2$ byte page table entries.

(A)

What is the minimum page size in bytes so that the page table for a segment requires at most one page to store it? Assume that the page size can only be a power of $2$ .

(B)

Now suppose that the pages size is $512$ bytes. It is proposed to provide a TLB (Transaction look-aside buffer) for speeding up address translation. The proposed TLB will be capable of storing page table entries for $16$ recently referenced virtual pages, in a fast cache that will use the direct mapping scheme. What is the number of tag bits that will need to be associated with each cache entry?

(C)

Assume that each page table entry contains (besides other information) $1$ valid bit, $3$ bits for page protection and $1$ dirty bit. How many bits are available in page table entry for storing the aging information for the page? Assume that the page size is $512$ bytes.