Question 1
Question
In 8085 microprocessor, the value of the most significant bit of the result following the execution of any arithmetic or Boolean instruction is stored in the
Answer
-
carry flag
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auxiliary carry flag
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sign flag
-
zero flag
Question 2
Question
How many bytes in a double word ?
Answer
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1 byte
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2 bytes
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3 bytes
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4 bytes
Question 3
Question
What is the value of AX register after executing,
MOV AX,456h,
CMP AX,456h
Question 4
Question
The instruction AND AH,11110111 is equivalent to
Answer
-
Sub AH, 8, if 4th bit of AH is set
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Sub AH, 8, if 4th bit of AH is cleared
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Sub AH, 4, if 4th bit of AH is set
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None of the above
Question 5
Question
The debug command U
Answer
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Retrieve the assembly program instructions from the disk
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Retrieve the assembly program instructions from the RAM
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Convert the machine code stored in memory into assembly equivalent
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None of the above
Question 6
Question
The debug command: -E F000:0 1 2 3
Answer
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Has no effect, because that location in ROM
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Will write three bytes (1,2,3) starting at location F000:0
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Depends on the processor
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Invalid command
Question 7
Question
Consider the program segment:
Age DB 100
MOV Age,123
What is the memory-addressing mode of the first operand in the MOV instruction?
Question 8
Question
The multiple Segment:Offset representations for a unique physical address is:
Answer
-
Advantage for 8086 processor to provide flexibility
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Disadvantage for 8086 processor, it make it harder to program
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Has no effect.
Question 9
Question
Algorithms are designed using combinations of three main building blocks (control structures), called...
Answer
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loops, if/then/else statements and functions
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quark, strangeness and charm
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syntax, choice and loops
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sequence, selection and repetition
Question 10
Answer
-
is written with specialised editing software
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cannot describe if...then...else constructs
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provides a pictorial representation of an algorithm
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has features of both English and computer languages
Question 11
Question
In an 8085 microprocessor, the instruction CMP B has been executed while the content of the accumulator is less than that of register B. As a result
Answer
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Carry flag will be set but zero flag will be reset.
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Carry flag will be reset but zero flag will be set.
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Both Carry flag and zero flag will be reset.
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Both Carry flag and zero flag will be set.
Question 12
Question
Consider the sequence of 8085 instructions given below:
LXI H, 9258
MOV A, M
CMA
MOV M, A
which one of the following is performed by this sequence?
Answer
-
Contents of location 9258 are moved to the accumulator.
-
Contents of location 9258 are compared with the contents of accumulator
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Contents of location 9258 are complemented and stored in location 9258
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Contents of location 5892 are complemented and stored in location 5892
Question 13
Question
The 2' s complement representation of the decimal value (minus) - 15 is
Question 14
Question
The instruction, MOV AX, 1234H is an example of
Question 15
Question
Match the following:
1. A Push Instruction a. Pre Increment the SP
2. A Pop Instruction. b. Post Increment the SP
c. Pre Decrement the SP
d. Post Decrement the SP.
Answer
-
1-> a, 2 -> b
-
1->b, 2 -> c
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1-> c, 2 -> d
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1-> d, 2->a
Question 16
Question
In 8085, which of the following modifies the program counter ?
Question 17
Question
The instruction that is used as prefix to an instruction to execute it repeatedly until the CX register becomes zero is
Question 18
Question
In 8086 microprocessor one of the following statements is NOT true.
Answer
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Coprocessor is interfaced in MAX mode
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Coprocessor is interfaced in MIN mode
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I/O can be interfaced in MAX / MIN mode
-
Supports pipelining
Question 19
Question
The status flag that cannot be operated by direct instruction is
Question 20
Question
Interfacing devices for DMA controller, programmable interval timer are respectively
Answer
-
8257, 8253
-
8253, 8257
-
8257,8251
-
8251,8257
Question 21
Question
Which of the following are the three basic sections of a microprocessor unit?
Answer
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operand, register, and arithmetic/logic unit (ALU)
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control and timing, register, and arithmetic/logic unit (ALU)
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control and timing, register, and memory
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arithmetic/logic unit (ALU), memory, and input/output
Question 22
Question
The instruction, MOV AX, [BX] is an example of
Question 23
Question
Which of the following instruction is NOT valid?
Answer
-
MOV AX, BX
-
MOV DS, 5000H
-
MOV AX, 5000H
-
PUSH AX
Question 24
Question
The instruction that is used for finding out the codes in case of code conversion problems is
Question 25
Question
The instruction that performs logical AND operation and the result of the operation is not available is
Question 26
Question
The instruction that is NOT valid is
Answer
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MOV AX, [BX]
-
MOV AX, 5555H
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MOV AX, [SI]
-
MOV [SI], [DI]
Question 27
Question
In 8086 microprocessor, the stack segment may have a memory block of a maximum of
Answer
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32K bytes
-
64K bytes
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16K bytes
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8K bytes
-
Unlimited bytes.
Question 28
Question
In 8086 the overflow flag is set when______.
Answer
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The sum is more than 16 bit
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Carry and sign flags are set
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Signed numbers go out of their range after an arithmetic operation
-
During subtraction
Question 29
Question
Direction flag is used with ____.
Answer
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String instructions
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Arithmetic Instructions
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Stack Instructions
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Branch Instructions
Question 30
Question
If_________ flag is set; the processor enters the single step execution mode.
Answer
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Direction
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Trap
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Interrupt
-
Zero
Question 31
Question
If segment address = 1005 H, offset address = 5555 H, then the physical address is_____.
Answer
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6555A H
-
155A5 H
-
45500 H
-
56555 H
Question 32
Question
BHE of 8086 microprocessor signal is used to interface the_____
Answer
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I/O
-
DMA
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Even bank memory
-
Odd bank memory