Code: AC23                                  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.

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

Q.1 A    Choose the correct or best alternative in the following:                                   (2x10)

a. The first modern computer was called_____________.

(A) FLOW-MATIC                            (B) UNIVAC-I

(C) ENIAC                                         (D) INTEL

b. If the reference voltage is –5V.The step voltage at the output of DAC0830 will be_________.

(A) +0.0196 V                                    (B) –0.0196V

(C) +0.196V                                       (D) –0.00196V

c. Software command CLEAR MASK REGISTER in DMA

(A) Disables all channels.                    

(B) Enables all channels.

(C) None.                                          

(D) Clears first/last flip-flop within 8237.

d. The condition indicated by logic 0 on 8086/8088   pin is____________

(A) µp is reading from memory.

(B) µp is writing from the memory.

(C) Both read and write operation       

(D) None of the above

e.    The hardware difference that appears on pin 34 of  8086 and  8088 is

(A)  8086 has /S7 pin and 8088 has SSO pin.                                                       

(B) 8088 has /S7 pin and 8086 has SSO pin.

(C) 8086 has M/IO pin and 8086 has /S7 pin.                                                       

(D) None of the above.

f. The first task of DOS operating system after loading into the memory is to use the file called___________.

(A) HIMEM.SYS                               (B) CONFIG.SYS

(C) AUTOEXEC.BAT                        (D) SYSTEM.INI

g.    If the programmable counter timer 8254 is set in mode 1 and is to be used to count six events, the output will remain at logic 0 for _____ number of counts

(A) 5                                                   (B) 6

(C) 0                                                   (D) All of the above

     B.     State TRUE or FALSE

             h.    The flash memory is programmed in the system by 12 V programming pulse.

(A)  TRUE                                          (B) FALSE

i. A plug and play (PnP) interface is one that contains a memory that holds configuration information of the system.

(A)  TRUE                                          (B) FALSE

             j.    The accelerated graphics port (AGP) allows virtually any microprocessor to be interfaced with PCI bus via the use of bridge interface.

(A)  TRUE                                          (B) FALSE

Answer any FIVE Questions out of EIGHT Questions.

Each question carries 16 marks.

Q.2     a.   Explain with proper diagram all the six modes of operation of programmable interval timer 8254.                                                               (8) (6)

             b.   What is a macro? Discuss different conditional constructs/statements used while programming a macro.                                                                  (4)

c.   Compare and contrast 8086 and 8088 microprocessors.                                    (4)

Q.3     a.   Select proper instructions or set of instructions  for each of the following tasks-

(i).     Develop a sequence that adds AL, BL, CL, DL and AH. Save the sum in DI register.

(ii).    Write a sequence of instructions that cube the 8-bit number found in DL. Load DL with a 4 initially and make sure the result is a 16-bit number.

(iii).   Write short sequence that clears (0) the three leftmost bits of DH without changing the remainder DH and stores the result in BH.

(iv).   Write a short sequence that sets (1) the rightmost five bits of DI without changing its remaining bits and saves the result in DI.                  (6)

             b.   A 450 ns EPROM won't work directly with a 5MHz 8088.Why? Explain.          (2)

c.   What is an interrupt? Discuss all the five software interrupt instructions.               (6)

             d.   State how real mode interrupts are different from protected mode interrupts?                      (2)

Q.4     a.   Discuss internal registers in detail of DMA controller 8237 with neat block diagram.            (8)

b.   Discuss the features of EISA bus.                                                                       (4)

c. State how 80386 & 80486 microprocessors are different from their earlier versions 80286 and 8086/8088 microprocessors?                                (4)

Q.5     a.   Discuss programmable keyboard and display interface -8279 control word summary.                     (8)

     b.   State the importance of PUBLIC, EXTRN directives in modular programming.                   (4)

c.   What is the main difference between 16 bit and 32 bit versions of C/C++ while using in line assembler.                                                                  (4)

  Q.6     a. Write short note on any ONE

(i)  USB

(ii) DOS and BIOS calls                                                                                    (4)

             b.   With proper bus timing diagrams explain all T states in read/write cycles of a micro-processor 8086.                                                                      (8)

             c.   State the functions of the following commands in 8087 arithmetic coprocessor  

                   (i) FLDCW                                         (ii) FRNDINT                                                                                        

                   (iii) FCOM                                          (iv) FCHS                                              (4)

Q.7     a.   Explain how memory management is improved in Pentium processors?                (4)

             b.   Discuss the two hardware interrupts in 8086/8088 microprocessors-                  (4)

c. State the use of following pins in 8086/8088 microprocessors:

(i)   

(ii)    ALE

(iii)

(iv)   DEN                                                                                                          (4)

             d.   Mention how do the following instructions differ in their functionality-                   (4)

(i)    NEG & NOT                              (ii)  DIV & IDIV

                                                                              (iii) AND & TEST            (iv) CMP & SUB

Q.8     a.   Why memory decoding is required? Describe 74LS139 memory decoder (4)

b. How can one make use of DOS function calls? Explain with the help of an example.                       (6)

             c.    Explain the flag registers and purpose of each flag bit in 8086                             (6)

Q.9     a.   Explain data addressing modes (with examples) available in microprocessors.                     (8)

             b.   Explain the difference between the memory mapped I/O and isolated I/O.           (4)

c. What is the use of these assembler directives-?

                                                                 (i) MODEL                                (ii) PROC           (2)

d.   (i) Convert binary number in two's compliment form   0100 1000

                                                                 (ii) Convert hexadecimal to BCH   83D   (2)