A simple page translation technique

then the paging unit is activeI mapping of a linear address to a physical address involves a paging technique. then the Pd bit of the control register CoM is setI the paging unit is activeI and thus the segment requires a second level of address translation. The Pd bit is usually set by the operating system to implement page oriented protection.

Paging is used to separate the tasks and create an independent virtual address space for every task in the memory. As a key taskI the paging unit checks the requested access type against the access rights of the linear addressI and generates a page fault exception if the memory access is invalid. Physical FRnWLnXRXs DGGUHssHs DUH gURXSHG LnWR fixHG OHngWK FKXnNs called a page or a physical page (usually of 4K byte).

In an x86-systemI a PO-bit linear address is divided into WKH IROORwLng WKUHH fiHOGs: • Directory • Table • lffset