7.3c Set-Associative Cache

Set-Associative Cache

A $N$-byte, $K$-bytes-per-block, $M$-way associative cache of $\frac{N}{K}$ blocks requires both a write policy and a replacement policy to store memory blocks in $M$ clusters of the same index, such that $N_i={\log }_2(\frac{N}{M\cdot K})$. The length of the tag (metadata) is therefore equal to
$N_t=N-N_i-N_o,$
where $N_o=lo{g}_2(K)$ is the number of bits allocated to the offset, or the length of every block.