8085 interview questions and answers

1. How can signals be classified for the 8085 microprocessor?

2.Describe briefly the accumulator register of 8085.

3.What is a stack pointer register? - 8085

4.Flag register in the 8085 microprocessor

5.Control and timing circuitry of the 8085.

6.What are the boons and banes of having more general purpose registers in a microprocessor.

7.What are WAIT states in microprocessors? - 8085

8.Steps involved in a Fetch Cycle - 8085

9.Flow of a typical Instruction Word - 8085

10.Externally initiated operations - 8085

11.What differences can you state between the HLT and HOLD states? - 8085

12.Different types of data transfers possible in the 8085.

13.Explain all the addressing modes of the 8085 with the help of examples.

14.What happens when the INTR signal goes high in the 8085

15.Explain briefly the TRAP input for the 8085.

16.What are the two major differences between INTR and other interrupts ( hardware)? - 8085

17.Classify interrupts on the basis of signals. State their differences. - 8085

18.Write a program that will store the contents of an accumulator and flag register at locations 2000H and 2001H.

19.Interrupt driven mode of data transfer - 8085

20.Various functional blocks of the 8085 microprocessor. - 8085

Q1. Why was 8085 microprocessor introduced?
Q2. How is the 8085 microprocessor different from the previous 8 series microprocessors?
Q3. How many instruction bits does 8085 processor support?
Q4. What is the maximum clock frequency used by the 8085 microprocessor?
Q5. What was is the primary usage of a 8085 microprocessor?
Q6. Define the architecture of the 8085 microprocessor?
Q7. What is the significance of the control unit in the 8085?
Q8. Name the unit that controls the sequential execution of instructions?
Q9. State the total number of pins in the 8085 microprocessor?
Q10. What is the significance of the HOLD and HLDA pins?
Q11. The Input/Output signals are related to which pins?
Q12. In 8085, power and frequency can be checked by connecting the wire with which pins?
Q13. What are the total number of input and output ports in 8085?
Q14. Define the types of bus used in the 8085?
Q15. How many bit address bus does the 8085 use?
Q16. Why is the address bus in the 8085 tri-stated and unidirectional?
Q17. How are time delays calculated in the 8085?
Q18. Define the types of memory used in 8085 microprocessor?
Q19. What is the difference between program memory and data memory?
Q20. What is the the total addressable memory size in a 8085 microprocessor?
Q21. What are the steps involved in communication of 8085 microprocessor with the memory?
Q22. What are the different types of instructions of 8085?
Q23. Give an example of a combined addressing mode instruction?
Q24. What is the purpose of data moving instructions? name any two such instructions?
Q25. What type of instruction is CPI ‘C’ and define the action it performs?
Q26. What does the OUT instruction do, define its format?
Q27.What are the different types of arithmetic operations that can be performed by the 8085 microprocessor? Explain with an example?
Q28. What are the different flags included in the ALU?
Q29. What is the purpose of the sign flag in 8085?
Q30. Define the 8085 instruction format and their classification according to word size?
Q31. Define the type of interrupts in the 8085 processor?
Q32. State the order of interrupts priority wise (lower to higher) ?
Q33. How do vectored and non-vectored interrupts differ?
Q34. Describe the non-vectored interrupt process?
Q35. What type of interrupt is the “trap” and what does it do?
Q36. State an interrupt that is not level sensitive?
Q37. Differentiate between hardware and software interrupts and state examples for both?
Q38. What are the different type of registers used in 8085?
Q39. Which Register handles the arithmetic operations in the 8085?
Q40. State the two type of 16 bit registers and define them?
Q41. What is the purpose of a buffer register in reference to 8085?
Q42. What are the general purpose registers in 8085?
Q43. What are the control signals used by the 8085?
Q44. The operation being performed by the 8085 can be checked by which pins?
Q45. What is the purpose of the ALE pin?
Q46. How is the system clock calculated in the 8085?