Solutions
Memory: Address Contents 000000ac Page Table Address: 0000e0a8 000000b0 000000b4 . . . 000080ac 000080b0 000080b4 . . . 0000e0ac 80000000 0000e0b0 8000000e 0000e0b4 8000a0b4
Q. Assuming 4K pages and assuming the physical address from the TLB is 000000b4, what is the tag field?
A. "Physical address from the TLB" means the physical address produced using the TLB. Since the page offset is 0b4, the physical page number is 00000. Which page table entry maps to that physical page number? The page table entry at 0...0e0ac. Subtracting from this the page table address yields: 0000e0ac - 0000e0a8 = 4. This is an address, which by dividing by 4, we can convert to a virtual page number: 4/4 = 1. So, 00001 must be in the tag field.