A system has a Translation Lookaside Buffer (TLB) that has a reach of 1 MB.…
2026
A system has a Translation Lookaside Buffer (TLB) that has a reach of 1 MB. TLB reach is defined as the total amount of physical memory that can be accessed through the TLB entries. The paging system uses pages of size 4 KB. The virtual address space is 64 GB and physical address space is 1 GB. If each TLB entry stores a 4-bit process id, page number, frame number, and a 2-bit control field, then the size of the TLB (in bytes) is ___________. (answer in integer)
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Correct answer: 1536
First, calculate the number of TLB entries. TLB Reach is 1 MB and Page Size is 4 KB. Number of Entries = 1 MB / 4 KB = 256 entries.
Next, determine the bits required per entry. PID is 4 bits. Control field is 2 bits.
Page Number (VPN) bits: Virtual Address Space is 64 GB (2^36). Offset is 12 bits (4 KB). VPN = 36 - 12 = 24 bits.
Frame Number (PFN) bits: Physical Address Space is 1 GB (2^30). Offset is 12 bits. PFN = 30 - 12 = 18 bits.
Total bits per entry = 4 (PID) + 24 (VPN) + 18 (PFN) + 2 (Control) = 48 bits.
Total TLB Size = 256 entries * 48 bits = 12288 bits. Convert to bytes: 12288 / 8 = 1536 bytes.