Microprocessor Multiple Choice Questions on “Segmentation”.
1. The bit that indicates whether the segment has been accessed by the CPU or not is
a) base address
b) attribute bit
c) present bit
d) granular bit
Answer: b
Clarification: The accessed bit or attribute bit (A) indicates whether the segment has been accessed by the CPU or not.
2. The TYPE field of a descriptor is used to find the
a) descriptor type
b) segment type
c) descriptor and segment type
d) none
Answer: c
Clarification: The type field decides the descriptor type and hence the segment type.
3. If the segment descriptor bit, S=0, then the descriptor is
a) data segment descriptor
b) code segment descriptor
c) system descriptor
d) all of the mentioned
Answer: c
Clarification: If S=0, then system descriptor. If S=1, then code or data segment descriptor.
4. The bit that indicates whether the segment is page addressable is
a) base address
b) attribute bit
c) present bit
d) granularity bit
Answer: d
Clarification: The granularity bit indicates whether the segment is page addressable.
5. If the Default operation size bit, D=1, the code segment operation size selected is
a) 8-bit
b) 16-bit
c) 32-bit
d) 64-bit
Answer: c
Clarification: If D=1, the segment selected is 32-bit operand segment, else, it is a 16-bit operand segment.
6. The segment descriptor contains
a) access rights
b) limit
c) base address
d) all of the mentioned
Answer: d
Clarification: The segment descriptors are 8-byte quantities containing access right or attribute bits along with the base and limit of the segments.
7. Which of the following is not a type of segment descriptor?
a) system descriptors
b) local descriptors
c) gate descriptors
d) none
Answer: d
Clarification: The five types of segment descriptors of 80386 are:
1. Code or data segment descriptors
2. System descriptors
3. Local descriptors
4. TSS(task state segment) descriptors
5. Gate descriptors.
8. The limit field of the descriptor is of
a) 10 bits
b) 8 bits
c) 16 bits
d) 20 bits
Answer: d
Clarification: The limit field of the descriptor is of 20 bits.
9. The starting address of the segment in physical memory is decided by
a) physical memory
b) segment descriptors
c) operating system
d) base address
Answer: c
Clarification: The base address that marks the starting address of the segment in physical memory is decided by the operating system and is of 32 bits.
10. The total descriptors that the 80386 can handle is
a) 2K
b) 8K
c) 4K
d) 16K
Answer: d
Clarification: 80386 can handle total 16K descriptors and hence segments.