PART - A
1. Differentiate between memory mapped I/O and I/O mapped
2. Classify the different groups of 8085 instruction set
3. Differentiate between unidirectional buffer and
4. What is the need for ALE signal in 8085 microprocessor?
5. Give the operation of the foll
instructions:(a) DAA (b) DEC.
6. State the functions for ALE and TRAP pins in 8085.
7. If the frequency of the crystal connected to 8085 is
6MHz, calculate the time to fetch and executed NOP
8. What is a MPU?
9. What do you mean by multiplexing the bus?
10. List out the two parts of an instruction.
11. What is a program counter?
12. What is an instruction?
13. What is PSW?
14. Define - Interrupt.
15. What are the addressing modes for 8085 microprocessor?
16. Where the READY signal used?
17. Define stack.
18. Specify how a program counter is useful in program
19. How the data and address lines are demultiplexed?
20. Show the bit positions of various flags in 8085 flag
21. List the various machine cycles of 8085.
22. What is the instruction format of 8085.
23. What are the similarity and difference between subtract
and compare instructions?
24. List the type of signals that have to be applied to
initiate hardware interrupts in 8085.
25. Write a subroutine to clear the flag register and
26. Draw a simple circuit to decode three controls signals
RD, WR, IO/M and to produce separate
read/write control signal for memory and I/O device?
27. List out the similarities between CALL_RET and PUSH_POP
28. List four interrupts of 8085.
29. Give the clock out frequency and state time T of 8085
when the crystal frequencies are:
(a) 5 MHz (b)
30. How many times the given loop will be executed? What
will be the contents of HL pair when the program control reaches to HLT
MVI A, 00h
Loop: DCX H
31. Define: (a) Instruction Cycle (b) M/c cycle (c) T-state.
32. Explain the execution of the instruction CMA M in 8085.
34. If the program counter is always one count ahead of the
memory locations from which the machine code is
being fetched, how does the microprocessor change the sequence of program
execution with a "Jump" execution?
35. Differentiate between hardware interrupts and software
interrupts of 8085.
36. What is DAD and what are the flags, affected by this
37. What is the function performed by SIM Instruction?
38. What is meant by processor cycle?
39. What are the different memory mapping schemes? Give any
one advantage and disadvantage for
40. Write an 8085 assembly language program, which checks to
see if the number is even or odd returns a
'0' in B register else returns a '1'.
PART - B
1. (i) Draw the pin configuration of 8085 and explain the
functional usage of each pin in details.
(ii) Write a
8085 program to generate a delay of 0.6 sec for the given crystal frequency of 5 MHz.
2. (i) Explain hardware interrupts in 8085.
(ii) Draw the
timing diagram for MVI A, 30H instruction.
(iii) What do
you mean by polling in 8085.
3. Write a 8085
assembly language program to generate a delay of 0.1 sec for the given crystal
frequency of 2 MHz.
4. (i) With suitable examples, explain the addressing modes of
5. (i) Draw the timing diagram of I/O read cycle in 8085 and
(ii) Interface a
8-bit DIP switch with 8085 such that the address assigned to it is FFH.
6. Explain the 8085
7. Write a 8085
program to convert a binary number to decimal.
8. (i) Write a 8085 program for multiplying two 8 bit numbers.
(ii) Write an
assembly language program to evaluate the expression (A+(B*C))/D, where A, B, C and D
are single byte integer.
9. (i) Draw the timing diagram of opcode
and memory write machine cycles of 8085 for following
instructions: MOV V, M; MVI D, data; IN OL; OUT 01; LDA 8000; RST7
(ii) What is the
data transfer instruction? Give example.
10. Write an assembly language program based on 8085
microprocessor to implement a look-up table
translation to generate the codes for seven-segment display with our digits. (Assume INPUT
PORT O D 6 H, and OUTPUT PORT OD 4H)
11. (i) Write an 8085 assembly
language program to perform 32 bit binary addition.
(ii) What will
be the value in ACC, for the given 8085 program below:
MVI C, 7F
MVI B, 3E
12. (i) Write an 8085 assembly
language program to fill a block of 1000H bytes starting at address 9000H
with characters 2BH.
(ii) Indicate the logic levels on each control or status pin
as logic '0' or logic '1' for 8085 microprocessor with the given data below;
O/P code fetch
14. With example explain different groups of instruction
15. (i) Analysis the program and
find the content of A register after execution.
MVI A, 07
8085 interrupts in detail.
16. (i) Draw and explain the
timing diagram for STA 4500 instruction.
(ii) Write as
assembly language program to find the average of N numbers.
17. Interface 3 numbers of 8KB EPROM and 5 numbers of 8KB
RAM to microprocessor 8085 to have a
total memory capacity of 64 KB.
18. (i) Write an assemble language
program to add two 2-digit BCD numbers.
19. Write notes on status flag.
20. Write an assembly language program to find the biggest
and smallest in an array of given numbers.
21. Write a program to count continuously in hexadecimal
from FFB to 00H in a system with a 0.5
micro sec clock period. Use register C to set up a one milli
second delay between each
count and display the number at one of the output ports.
22. (i) Draw a flowchart and 8085
assembly language program for adding the two hexadecimal
numbers 9BH and A7H in register D and E respectively,. If the sum is greater than
FFH, display 01H at output PORT0: otherwise, display the sum.
(ii) Draw the
timing diagram for IN and OUT instructions.
23. Explain with the help of suitable diagram how the INTR
pin can be used to interrupt the 8085 and how it responds to the signal.
24. (i) Explain the logic
instructions of 8085 microprocessor with examples.
(ii) Write and
ALP using 8085 instruction set to add two n-byte numbers stored at memory locations
starting at 'X' and 'Y' respectively. Store the result and memory location
starting from 'Z'. Draw the flow chart.
25. (i) List all the control
signals of the Timing and Control Unit. Explain the sue of each of these
(ii) Write an ALP
to evaluate the expression C = A2 + B2
26. (i) What are the features of
FIFO and LIFO memory structures?
27. Draw and explain the timing diagram for the execution of
the instruction LDA 2080H.
28. (i) How do you classify the
8085 interrupts what are they? How is the interrupt branch address
obtain in each case?
(ii) Draw the
timing diagram of DCX instruction.