Engineering Questions with Answers - Multiple Choice Questions
Microprocessors MCQ – Real Addressing Mode
1 - Question
The 80286 CPU acts just like that of 8086 when operated in
a) real addressing mode
b) protected virtual address mode
c) real and protected virtual address modes
d) none of the mentioned
View Answer
Answer: a
Explanation: In the real addressing mode of operation of 80286, it just acts as a fast 8086.
2 - Question
In real addressing mode, the 80286 addresses a physical memory of
a) 16 MB
b) 8 MB
c) 2 MB
d) 1 MB
View Answer
Answer: d
Explanation: In real addressing mode, the 80286 addresses a physical memory of 1 Mbytes using A0-A19. The lines A20-A23 are not used by the internal circuit of 80286 in this mode.
3 - Question
In real addressing mode, the 80286 operates at a speed
a) faster than that of 8086
b) half of that of 8086
c) slower than that of 8086
d) same as that of 8086
View Answer
Answer: a
Explanation: Because of extra pipelining and other circuit level improvements, in real address mode also, the 80286 operates at a much faster rate than 8086.
4 - Question
In physical memory, if the segment size limit is exceeded by the instruction or data then
a) instruction is not executed
b) exception is generated
c) saves to next segment automatically
d) none of the mentioned
View Answer
Answer: b
Explanation: An exception is generated if the segment size limit is exceeded by the instruction or the data.
5 - Question
The 80286 reserves fixed area of physical memory for
a) system initialization
b) interrupt vector table
c) system initialization and interrupt vector table
d) none of the mentioned
View Answer
Answer: c
Explanation: The 80286 reserves two fixed areas of physical memory for system initialization and interrupt vector table.
6 - Question
In the real mode, the memory that is reserved for interrupt vector table is
a) first 2 KB of memory
b) first 1 KB of memory
c) last 2 KB of memory
d) last 1 KB of memory
View Answer
Answer: b
Explanation: In the real mode, the first 1 Kbyte of memory starting from the address 00000H to 003FFH, is reserved for interrupt vector table.
7 - Question
In the real mode, the memory that is reserved for system initialization is
a) from 004FFH to 0FFFFH
b) from 004FFH to 05FFFH
c) from FFFF0H to FFFFFH
d) from FFF00H to FFFFFH
View Answer
Answer: c
Explanation: The addresses from FFFF0H to FFFFFH are reserved for system initialization, in real addressing mode.
8 - Question
When 80286 is reset, it always starts its execution in
a) protected virtual addressing mode
b) real addressing mode
c) either real or protected virtual address modes
d) none of the mentioned
View Answer
Answer: b
Explanation: When 80286 is reset, it always starts its execution in real addressing mode.
9 - Question
The 80286 in real addressing mode performs
a) initialization of IP
b) enables interrupts
c) sets up descriptor table
d) all of the mentioned
View Answer
Answer: d
Explanation: The 80286 in real addressing mode performs the following functions: it initializes IP and other registers of 80286, initializes the peripheral, enables interrupts, sets up descriptor tables, and then prepares it for entering the protected virtual address mode.
10 - Question
In real address mode, while addressing the physical memory, the 80286 uses the signal
a) HLDA
b) BHE (active low)
c) CAP
d) HOLD
View Answer
Answer: b
Explanation: In real address mode, while addressing the physical memory, the 80286 uses BHE (active low) along with A0-A19.