Phase 3 — Address Space (Weeks 9–12). Virtualization of memory is the conceptual centrepiece of OS. The TLB and page-table entries will make much more sense after Phase 1 because you will understand why the hardware/OS split exists.
As you go along, you need to finish the following topics:
Address Space — Concepts and Layout
Segmentation
Paging and Page Tables
TLBs — Translation Lookaside Buffers
Virtual Memory and Demand Paging
Page Replacement Policies
Thrashing
Swapping
Memory-Mapped Files
Shared Memory and Copy-on-Write
Multi-level Page Tables
Heap and Stack — Runtime Memory