AMIETE – ET/CS/IT (NEW SCHEME) – Code: AE66/AC66/AT66

Subject: MICROPROCESSORS & MICROCONTROLLERS

Time: 3 Hours Max. Marks: 100

NOTE: There are 9 Questions in all.

· Question 1 is compulsory and carries 20 marks. Answer to Q.1 must be written in the space provided for it in the answer book supplied and nowhere else.

· Out of the remaining EIGHT Questions answer any FIVE Questions. Each question carries 16 marks.

· Any required data not explicitly given, may be suitably assumed and stated.

Q.1 Choose the correct or the best alternative in the following: (210)

a. INTEL 8085 processor has the following number of address and data pins.

(A) 16, 8 (B) 18, 8

(C) 20, 16 (D) 20, 8

b. To address 1 K bytes of memory, the address lines required are

(A) 11 (B) 10

(C) 8 (D) 4

c. The two’s complement of the number 55 is given by

(A) CD (B) AB

(C) AC (D) BD

d. The decimal value of a signed binary number 101101 is

(A) -13 (B) 13

(C) -12 (D) 12

e. One among the following instructions is not a logic instruction. Identify.

(A) ADC B (B) ANA B

(C) ORI 05 (D) ORA B

f. The number of hardware interrupts available in 8085 is

(A) 5 (B) 6

(C) 4 (D) 2

g. For adjusting the result after addition of two BCD numbers, the following instruction is used

(A) DAA (B) NOP

(C) STC (D) CMA

h. RIM instruction is used for

(A) Parallel data output (B) Restart

(C) Serial data communication (D) Ready

i. Which one of the following interrupts works with edge and level triggering (both) but is also maskable?

(A) RST 4.5 (B) RST 5.5

(C) RST 6.5 (D) RST 7.5

j. The A & B registers in 8051 microcontroller are used for

(A) Arithmetic operation (B) Complex numbers

(C) Complementing signed numbers (D) Memory operation

Answer any FIVE Questions out of EIGHT Questions.

Each question carries 16 marks.

Q.2 a. Perform the following using 2’s complement arithmetic:

(4)

b. Draw the pin diagram of 8085 and cite the function of each pin. (8)

c. What are the purpose of the following pins in 8085 microprocessor?

(i) ALE (ii) READY

(iii) HOLD (iv) HLDA (4)

Q.3 a. Identify the addressing mode of the following instructions:

(i) MOV A, M (ii) MVI C,0A

(iii) LDA addr (iv) MOV A,B (4)

b. Two RAMs of 4 KB each are to be interfaced with 8085. Give in detail the set up for interfacing, decoding circuits and address map. (8)

c. Explain the timing diagram of MOV A,B. (4)

Q.4 a. Add two 8 digit BCD numbers by writing an Assembly Language Program with 8085 microprocessor’s instruction set. Provide explanatory comments with a source program and a flowchart. (8)

b. Write an assembly language programming with 8085 microprocessor to convert a given byte into two nibbles and vice versa. Provide also explanatory comments in each step of the programming. (8)

Q.5 a. Explain the structure of RIM and SIM instructions format. What are the other uses of this format? (6)

b. Give the interrupt structure of 8085 and explain their triggering methods. (6)

c. What is the control word of 8255 operated in BSR mode to make bit 6 to set? (4)

Q.6 a. Write a program to display decimal count minutes and seconds only. Generate your own delay, taking 8085 microprocessor working with 3MHz clock. (8)

b. Draw the block diagram of Intel 8279 and explain its salient features. (8)

Q.7 a. Explain the control words of 8259(PIC). (6)

b. Explain the concept of DMA operation with block diagrams. (4)

c. Give the block diagram of 8257 DMA controller and explain its working. (6)

Q.8 a. Describe the modes of 8253 (PIT) with neat waveforms. (8)

b. Giving the block diagram of a USART explain, step by step the working of synchronous serial communication. (8)

Q.9 a. Give the architecture of a 8051 microcontroller and explain the function of each block. (6)

b. What are the addressing modes used in 8051 microcontroller? Illustrate with an example for each mode of addressing. (8)

c. State what are the functions of Watch-dog timer. (2)