Code: C-23 Subject: MICROPROCESSOR BASED SYSTEM DESIGN
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. Questions in ITALICS are choice questions.
· Any required data not explicitly given, may be suitably assumed and stated.
Q.1 Choose the correct or best alternative in the following: (2x10)
a. A certain SRAM has 
, 
and 
. In which of the
following modes this SRAM is operating
(A) Read (B) Write
(C) Stand by (D) None of the above
b. Assume an 8086 processor executes the instruction MOV BH, [SP]. Calculate the physical address of the memory operand assuming SS = E010 h, DS = 1A00 h, SP = 0200 h and SI = 0100 h.
(A) 1A100h (B) EO300h
(C) 1B00h (D) E210h
c. Which of the following is true with respect to EEPROM
(A) contents can be erased byte wise only.
(B) contents of full memory can be erased together.
(C) contents can be erased using ultra violet rays
(D) contents can not be erased
d. Pseudo instructions are basically
(A) false instructions.
(B) instructions that are ignored by the microprocessor.
(C) assembler directives.
(D) instructions that are treated like comments.
e. Number of the times the instruction sequence below will loop before coming out of loop is
MOV AL, 00h
A1: INC AL
JNZ AL
(A) 00 (B) 01
(C) 255 (D) 256
f. What will be the contents of register AL after the following has been executed
MOV BL, 8C
MOV AL, 7E
ADD AL, BL
(A) 0A and carry flag is set (B) 0A and carry flag is reset
(C) 6A and carry flag is set (D) 6A and carry flag is reset
g. Direction flag is used with
(A) string instructions. (B) stack instructions.
(C) Arithmetic instructions. (D) Branch instructions.
h. Ready pin of a microprocessor is used
(A) to indicate that the microprocessor is ready to receive inputs.
(B) to indicate that the microprocessor is ready to receive outputs.
(C) to introduce wait states.
(D) to provide direct memory access.
i. These are two ways in which a microprocessor can come out of Halt state.
(A) When hold line is a logical 1.
(B) When interrupt occurs and the interrupt system has been enabled.
(C) When both (A) and (B) are true.
(D) When either (A) or (B) are true.
j. In the instruction FADD, F stands for
(A) Far. (B) Floppy.
(C) Floating. (D) File.
Answer any FIVE Questions out of EIGHT Questions.
Each question carries 16 marks.
Q.2 a. What do you mean by external and internal data bus? How are these two related in 8088 processor. (2)
b. The I/O bus is faster than the memory bus. Comment. (2)
c. What is the difference between XT and AT computer system? (2)
d. What are program-invisible registers? (2)
e. What is wrong with MOV [BX], [DI] instruction? (2)
f. What is the addressing mode of the following instructions:-
(i) MOV AX, 1234 (ii) MOV CX, [DX] (2)
g. The interrupt vector table is always created in the first 1K area of the memory. Justify the statement. (2)
h. What is the purpose of carry (c) flag and zero (z) flag? (2)
Q.3 a. What is 16-bit ISA? Compare it with 8-bit ISA bus. (6)
b. What do you understand by DRAM? How the processor reads and writes data into a DRAM location? How is refreshing of DRAM done? (6)
c. Compare memory mapped I/O with I/O mapped I/O. (4)
Q.4 a. Illustrate with the help of an example the concept of segment and offset addressing in 8086 processor. Which registers are used as an offset address for the data in DS. (6)
b. What are the functions of a DMA controller? Explain the various DMA modes. Describe in brief the steps that takes place during a DMA write cycle. (10)
Q.5 a. Explain in brief the functions of the clock generator chip, 8284. (4)
b. Write down the difference between
(i) 8086 and 8088.
(ii) 80386 SX and 80386 DX.
(iii) 80486 DX2 and 80486 DX4.
(iv) Pentium Pro and Pentium II. (8)
c. Write a brief note on MMX technology. (4)
OR
Q.5 a. How do you use DOS function calls? Illustrate with the help of an example. What is special about INT 21 h. (6)
b. How BIOS function calls differ from DOS function calls? (4)
c. What are the different modes in which 8255 Programmable Peripheral Interface (PPI) can operate? Write the 8086 initialisation routine required to program 8255 for mode 1 with Port A and Port B as output Ports and Port C as an input port. Indicate all the relevant signals. (6)
Q.6 a. 8086 has two hardware interrupt inputs : NMI and INTR. What is the difference between the two? (4)
b. Explain the operation of IRET instruction. What memory locations contain the vector for an INT 34 instruction? (4)
c. Write the sequence of instructions in 8086 assembly language to perform the following:
(i) Multiply two 32 bit numbers.
(ii) Shift right a number by 3 bits.
(iii) Invert right most four bits of AL. (4+2+2)
Q.7 a. What is the need of having coprocessor in a system? Draw and explain the block diagram that shows the interfacing of 8087 coprocessor to 8086. Explain data formats used in 8087. (8)
b. Explain the following terms:
(i) Branch prediction logic.
(ii) Paging.
(iii) Assembler.
(iv) Microprocessor development system. (8)
Q.8 a. Explain the following instructions:
(i) TEST (ii) NEG (iii) CMP (iv) DAA. (8)
b. With respect to serial communication define the following:
(i) baud rate. (ii) asynchronous communication.
(iii) parity. (iv) half duplex. (4)
c. What is the importance of RS232-C in serial communication? Name some application where you see its use. (4)
Q.9 Write short notes on (Any FOUR):-
(i) 8259.
(ii) Real time clock.
(iii) ADC Interfacing with 8086.
(iv) Assembler directives.
(v) Real and protected mode.
(vi) Super scalar architecture.
(vii) Comparison between Motorola processors and INTEL processors. (4 x 4 = 16)