Protected mode: Segment translation

Segment translation is one of the key areas in protected virtual address mode. It is typically a mechanism of converting a logical address into a linear address by the segmentation hardware of the MMU unit. then a program gets loadedI the linkerLloader loads the segmentation registers with the appropriate value. A protected mode segmentation register holds a 16-bit segment selector. And every segment selector has a linear base address associated with itI which is stored in the segment descriptor.

A 16-bit selector is used to store an index to access a segment descriptor in a descriptor table (descriptors were created by the linkerLloader). cigure O shows the format of a selector.

As PHnWLRnHG, WKH LnGHx fiHOG (ELWs [15:3]) KDs D vDOXH to access a descriptor in a descriptor table. This 1P-bit index fiHOG Ls sLPSOy PXOWLSOLHG Ey WKH sFDOH IDFWRU (L.H., WKH OHngWK