Question

A computer system implements a 40 bit virtual address, page size of 8 kilobytes, and a 128-entry translation look-aside buffer(TLB) organized into 32 sets each having four ways. Assume that the TLB tag does not store any process id. The minimum length of the TLB tag in bits is____

• A. 22

Answer 1

The correct option is A 22
Page size = 8 kB = $2^{13}$ bytes
$\Rightarrow$ 13 bits required for offset.
Number of sets in cache = 32
$\Rightarrow$ 5 bits required for index (set offset).

$\therefore$ 22 tag bits are required.