8085 Microprocessor MCQ

41. Which one of the following statements for Intel 8085 is correct?

1. Program counter (PC) specifies the address of the instruction last executed
2. PC specifies the address of the instruction being executed
3. PC specifies the address of the instruction be executed
4. PC specifies the number of instruction executed so far

42. The instruction RET executes with the following series of machine cycle

1. Fetch, read, write
2. Fetch, write, write
3. Fetch, read, read
4. Fetch, read

43. Which one of the following statements is correct regarding the instruction CMP A?

1. Compare accumulator with register A
2. Compare accumulator with memory
3. Compare accumulator with register H
4. This instruction does not exist

44. The instruction JNC 16-bit refers to jump to 16-bit address if

1. Sign flag is set
2. Carry flag is reset
3. Zero flag is set
4. Parity flag is reset

45. Consider the following interrupts for 8085 microprocessor:

1. INTR
2. RST 5.5
3. RST 6.5
4. RST 7.5
5. TRAP

If the interrupt is to be vectored to any memory location then which of the above interrupt is/are correct?

1. 1 and 2 only
2. 1, 2, 3 and 4
3. 5 only
4. 1 only

46. Consider the following statements:

1. Auxiliary carry flag is used only by the DAA and DAS instruction.
2. Zero flag is set to 1 if the two operands compared are equal.
3. All conditional jumps are long type jumps.

Which of the above statements are correct?

1. 1, 2 and 3 only
2. 1 and 2 only
3. 1 and 3 only
4. 2 and 3 only

47. Among the given instructions, the one which affects maximum number of flags is

1. RAL
2. POP PSW
3. XRA A
4. DCR A

48. XCHG instruction of 8085 exchanges the content of

1. top of stack with contents of register pair
2. BC and DE register pairs
3. HL and DE register pairs
4. None of the above

49. Direction flag is used with

1. String instructions
2. Stack instructions
3. Arithmetic instructions
4. Branch instructions

50. What will be the contents of DE and HL register pairs respectively after the execution of the following instructions?

LXIH, 2500 H
LXID, 0200 H
DAD D
XCHG

1. 0200 H, 2500 H
2. 0200 H, 2700 H
3. 2500 H, 0200 H
4. 2700 H, 0200 H

51. In 8085 microprocessor, the address for ‘TRAP’ interrupt is

1. 0024 H
2. 002C H
3. 0034 H
4. 003C H

52. A ‘DAD H” instruction is the same as shifting each bit by one position to the

1. left
2. right
3. left with a zero inserted in LSB position
4. right with a zero inserted in LSB position

53. When a program is being executed in an 8085 microprocessor, its program counter contains

1. the memory address as the instruction that is to be executed next.
2. the memory address of the instruction that is being currently matched.
3. the total number of instructions in the program being executed.
4. the number of instructions in the current program that have already been executed.

54. Which of the following data transfer is not possible in microprocessor?

1. Memory to accumulator
2. Accumulator to memory
3. Memory to memory
4. I/O device to accumulator

55. LOADER is a program that

1. loads the memories and generates a hex file
2. loads the hex file and converts to the executable file
3. loads the COM file and generates the binary code
4. loads English like command and generates the binary code

56. Which of the following instructions is closest match to the instruction POP PC?

1. RET
2. PCHL
3. POP PSW
4. DAD SP

57. How many machine cycles are required by STA instruction?

1. 2
2. 3
3. 4
4. 5

58. Which of the following 8085 instruction will require maximum T-states for execution? 

1. XRI byte
2. STA address
3. CALL address
4. JMP address

59. In 8085 microprocessor, which mode of addressing does the instruction CMP M use?

1. Direct addressing
2. Register addressing
3. Indirect addressing
4. Immediate addressing

60. With reference to 8085 microprocessor, which of the following statements are correct?

1. INR is 1 byte instruction
2. OUT is 2 byte instruction
3. STA is 3 byte instruction

1. 1 and 2 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3