\subsubsection{Multilevel Page Tables}
\content{Motivation} For a 48-bit Virtual Address Space with $4$KB ($= 2^{12}$ bytes) page size, the number of bits required is $2^{48} / 2^{12} \cdot 2^3 = 2^{39}$ bytes
(that is 512 GB). The $2^{3}$ bytes is the size of the page table entry (8 bytes).

Multi-Level page tables add further steps to this process: Instead of a PT we have a Page Directory Table (PDE) which contains the addresses of separate Page Tables.
The top of the VPN is used to index into each of these, which technically allows any depth of page tables.
