250+ TOP MCQs on Numeric Processor 8087 -2 and Answers

Tough Microprocessors Interview Questions & Answers on “Numeric Processor 8087 -2”.

1. Which of the following is not a data transfer instruction?
a) floating point data transfer
b) integer data transfer
c) arithmetic instruction
d) bcd data transfer
Answer: c
Clarification: The data transfer instructions are grouped into floating point data transfer, integer data transfer and BCD data transfer.

2. The instruction that performs real or integer multiplication of the specified operand with stack top is
a) AMUL
b) IMUL
c) RMUL
d) FMUL
Answer: d
Clarification: The FMUL instruction performs real or integer multiplication of the specified operand with stack top. The specified operand may be a register or a memory location.

3. When the instruction, FDIV is performed, the destination is
a) memory
b) stack top
c) register
d) stack bottom
Answer: b
Clarification: If the destination is not specified, the ST(Stack Top) is the destination and source must be a memory operand of short real or long real type.

4. When the instruction, FPREM, is performed, the data stored on to the stack top is
a) dividend
b) divisor
c) quotient
d) remainder
Answer: d
Clarification: The instruction divides the stack top (ST) by ST(1), and then stores the remainder to the stack top (ST).

5. If ‘x’ is the value stored at the top of the stack, then the instruction F2XMI calculates the expression
a) 2x
b) 2x+1
c) 2x-1
d) log(2x)
Answer: c
Clarification: The instruction F2XMI calculates the expression, 2x-1, where the value ‘x’ is stored at the top of the stack. The result is stored back at the top of the stack.

6. The content of the stack is compared with zero to check whether the content is zero, using the instruction
a) FCOM
b) FIST
c) FCOMP
d) FXAM
Answer: b
Clarification: The instruction FIST tests if the contents of the stack top is zero, and the condition code flags are accordingly modified.

7. The instruction that loads log 10 (to the base 2) to stack top is
a) FLDPI
b) FLDLG2
c) FLD2T
d) FLDLN2
Answer: c
Clarification: The instruction FLD2T loads the specified constant, log 10 (to the base 2) to the top of the stack.

8. The instructions that are used to program the numeric processor or to handle the internal housekeeping functions are
a) transcendental operations
b) comparison instructions
c) constant operations
d) coprocessor control instructions
Answer: d
Clarification: The coprocessor control instructions are used either to program the numeric processor or to handle the internal housekeeping functions like exception handling, flags manipulations, and processor environment maintenance.

9. When the instruction FINIT performs its function, then the TAG status is
a) set
b) empty
c) reset
d) zero
Answer: b
Clarification: This instruction performs the same function as the hardware reset. The control word is set to 03FF, and the TAG status is set to empty.

10. The instruction that enables the interrupt structure and response mechanism is
a) FINIT
b) FDISI
c) FENI
d) FLDCW
Answer: c
Clarification: The instruction FENI enables the interrupt structure and response mechanism of 8087.

11. The instruction that is used to store the environment of the coprocessor to a destination memory location is
a) FINCSTP
b) FLDENV
c) FFREE
d) FSTENV
Answer: d
Clarification: The instruction FSTENV is used to store the environment of the coprocessor to a destination memory location, specified in the instruction using any of the 8086 addressing modes.

12. The instruction that is the NOP instruction of the coprocessor is
a) CNOP
b) FNOP
c) SNOP
d) PNOP
Answer: b
Clarification: The FNOP is a NOP instruction of the coprocessor. No internal status or control flag bits change.