A CPU generates 32-bit virtual addresses. The page size is 4 KB. The processor…
2006
A CPU generates 32-bit virtual addresses. The page size is 4 KB. The processor has a translation look-aside buffer (TLB) which can hold a total of 128 page table entries and is 4-way set associative. What is the minimum size of the TLB tag?
- A.
11 bits
- B.
13 bits
- C.
15 bits
- D.
20 bits
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Correct answer: C
The page size is 4 KB, which equals 2^12 bytes, requiring a 12-bit page offset. The TLB has 128 entries with 4-way associativity, resulting in 128 / 4 = 32 sets. This requires a 5-bit index since log2(32) = 5. Subtracting the offset and index from the 32-bit virtual address (32 - 12 - 5) yields a tag size of 15 bits.
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