Intel Microprocessor Interview Question:

Explain briefly the characteristics of the program invisible registers?

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- The program invisible registers are used to access and specify the address tables of global and local descriptor tables.

- Since these types of register cannot be accessed directly by a program they are called invisible registers.

- The Global Descriptor table register contains the limit and the base addresses for the descriptor table. The same applies for the Interrupt descriptor table register.

- Since the maximum length is limited to 64 Kbytes the limit of each descriptor table is limited to 16 bits.

- The GTDR is loaded with the address of the global descriptor table whenever a protected mode operation is required.
Submitted by: Administrator