Explain associative memory page table.

Generally, a system has larger address space than the memory space. For a system of 1024K address space and 32K memory space with 1K block size, we have 1024 pages and 32 blocks. With this at most 32 pages can be in the physical memory. That means, in every time only 32 locations of the page table is used and 992 locations are not used. This leads to the high wastage of memory as the page table occupies memory corresponding to 1024 slots. Also the performance of the system is reduced. So, the more effective and efficient solution would be to maintain the page table with number of entries equivalent to the number of blocks rather than number of pages. In this way the size of the table is reduced and each slot of the table is fully utilized. This is possible with the help of associative memory with each entry (or word) containing a page number together with its corresponding block number.

e.g. For a system of 8K address space and 4K memory space with 1K of block size we can have page table with only 4 entries if we use associative memory page table.