microprocessor 4th sem questions

B.E DEGREE EXAMINATION, APRIL/MAY 2007

CS1304 – MICROPROCESSORS AND MICROCONTROLLERS

PART A – (10 x 2 = 20 marks)

1. How address and data lines are demultiplexed in 8085?
2. What is the function performed by SIM instruction in 8085?
3. What is pipelined architecture?
4. How the interrupts can be masked/unmasked in 8086?
5. What are the signals involved in memory bank selection in 8086
micro processor?
6. How clock signal is generated n 8086? What is the maximum internal clock
frequency of 8086?
7. What is the function of gate signal in 8254 timer?
8. Write the format of KW1 in 8259.
9. List the interrupts of 8051 micro controller.
10. What are register banks in 8051 microcontroller?

PART B – (5 x 16 = 80 marks)

11. (a) (i) Explain the various logical and arithmetic instructions available in 8085
microprocessor. (10)
(ii) Explain the function of various flags of 8085 microprocessor (6)
(Or)
(b) (i) Differentiate between I/O mapped I/O and memory mapped I/O. (6)
(ii) Write an 8085 assembly language program to convert 8 bit binary to
ASCII code. (10)

12. (a) (i) Describe the action taken by 8086 when INTR pin is activated. (6)
(ii) Write an assembly language program in 8086j to search the largest data in
an array. (10)
(Or)

(b) (i) Discuss the various addressing modes of 80896 microprocessor. (10)
(ii) Explain the following assembler directives used in 8086
(1) ASSUME
(2) EQU
(3) DW (

13. (a) (i) Explain in detail about memory access mechanism in 8086 (
(ii) Explain the function of following 8086 signals.
(1) HLDA
(2) RQ/GTO
(3) DEN
(4) ALE. (
(Or)
(b) (i) Draw and explain a block diagram showing 8086 in maximum mode
configuration. (12)
(ii) What are the advantages of the multiprocessor systems? (4)

14. (a) (i) With the help of block diagram explain the operation of USART (8251A)
(10)
(ii) Discuss the salient features of 8259 – programmable interrupt controller.
(6)
(Or)
(b) (i) Describe the various modes of operations in 8253 programmable interval
Timer. (
(ii) Explain the operation of DMA controller (8237).

15. (a) With a suitable block diagram, explain the architecture of 8051 microcontroller.
(16)
(Or)
(b) Discuss in detail about 8051 based stepper motor control along with necessary
hardware and software. (16)

2006

PART A – (10 ´ 2 = 20 marks)

1. Name the various Flag bits available in an 8085 microprocessor.
2. Give the significance of SIM and RIM instruction available in 8085.
3. What do you mean by pipelining in an 8086 processor?
4. How the 20 bit effective, address is calculated in an 8086 processor?
5. What is the purpose of CLK signal in an 8086 system?
6. What is the use of Latch signal on the AD0 – AD15 bus in an 8086 system?
7. Name the two modes used by the DMA processes to transfer data.
8. Name the six modes of operations of an 8253 programmable interval timer.
9. Differentiate a microprocessor and a microcontroller.
10. Differentiate RRA and RRCA instruction in 8051 microcontroller.

PART B – (5 ´ 16 = 80 marks)

11. (a) (i) With a neat block diagram explain the architecture of an 8085
Microprocessor? (12)
(ii) List out the Mask able and Non – Mask able interrupts available in an
8085 processor. (4)
(Or)
(b) (i) How do the instructions of 8085 is classified based on their functions
and word length? Give an example. (10)
(ii) Write an ALP to add two 8 bit numbers.

12. (a) (i) With the neat sketch explain the architecture of an 8086 processor.
(ii) Give the significance of O Flag, T Flag and I Flag, D Flag of 8086. (4)
(Or)

(b) (i) Explain in detail about the various addressing modes used in 8086
processor? Give an example. (12)
(ii) Name the various segment registers and their usage in 8086 processor. (4)

13. (a) (i) Explain the MIN/MAX mode operation of an 8086 processor. (10)
(ii) Give a note on the role of a decoder in memory interfacing with
example. (6)
(Or)
(b) (i) Explain in detail about the 8086 memory banks and the associated
signals for byte and word operations.
(ii) Give the significance of RQ/GTO and IO/M signals. (4)

14. (a) (i) With a neat sketch kand explain the operation of an Interrupt
controller(8259) (14)
(ii) What jis the use of CAS0, CAS1 and CAS2 signals?
(Or)
(b) Draw the block diagram of a DMA controller (8237) and explain its
operation.

15. (a) (i) With the help of a functional block diagram explain any one application
of 8051 microcontroller. (16)
(Or)
(b) Give the PIN details of an 8051 microcontroller and explain. (16)