Microprocessors And Interfacing March06 Rr312001

Set No. 1

Code No: RR312001

III B.Tech I Semester Supplementary Examinations, March 2006 MICROPROCESSORS AND INTERFACING (Production Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Draw the block diagram of 8085 Microprocessor. (b) Explain the following pins of 8085 Microprocessor. i. ii. iii. iv.

READY RESET OUT RST 7.5 ALE

[8+8]

2. (a) Explain the flag register of 8086. (b) Explain the concept of memory segmentation. (c) Explain, when Queue is failing to speed up the execution.

[6+6+4]

3. (a) Write a program to move a block of memory with out over lapping. (b) Write about the following instructions. i. ii. iii. iv.

ADC AAS IMUL CBW

[8+8]

4. (a) What is the necessity of NEAR or FAR attribute in PROC statement? (b) Give the sequence of instructions that would cause the register SI to be loaded from an externally defined variable COUNT ? (c) What is the necessity of relocation? Explain the support provided by 8086 for relocation capability? [4+4+8] 5. (a) Explain the following instructions and the flags that are affected by these instructions i. ii. iii. iv.

SCAS DST STOS DST MOVSW CMPSB

[2+2+2+2]

(b) With a 5-MHZ clock estimate the time needed to execute the following instruction sequence. [8] MOV SI, OFFSET STG 1 MOV DI, OFFSET STG 2 1 of 2

Set No. 1

Code No: RR312001

MOVE:MOV

MOV CX, 0010H AL, [SI] MOV [DI], AL INC SI INC DI LOOP MOVE

6. (a) Draw the block diagram of 8259 and explain each block? (b) Explain how IRET instruction is executed?

[8+8]

7. (a) What is BSR mode operation? How it is useful in controlling the interrupt initiated data transfer for mode 1 and 2? (b) Explain the transistor buffer circuit used to drive 7-segment LEDs?

[8+8]

8. (a) Explain demand transfer mode and block transfer mode of 8237? (b) Show how 8237s are cascaded to provide more number of DRQ’s and explain the operation? (c) Explain how memory to memory transfer is performed with 8237? ⋆⋆⋆⋆⋆

2 of 2

[6+5+5]

Set No. 2

Code No: RR312001

III B.Tech I Semester Supplementary Examinations, March 2006 MICROPROCESSORS AND INTERFACING (Production Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) List out the various addressing modes used in 8085 Microprocessor. (b) Explain the following pins of 8085 Microprocessor i. ii. iii. iv.

SID, SOD ALE HOLD,HLDA TRAP

[8+8]

2. (a) Explain the flag register of 8086. (b) Explain the concept of memory segmentation. (c) Explain, when Queue is failing to speed up the execution.

[6+6+4]

3. (a) Write a program to move a block of memory with out over lapping. (b) Write about the following instructions. i. ii. iii. iv.

ADC AAS IMUL CBW

[8+8]

4. (a) Write the sequence of statements that declare the word named ‘NWORD ’ and FAR label ‘EXTMOD’ as being external and the variable ‘IWORD’ and the label ‘LOCMOD’ as being local and accessile by other source modules? (b) Give the sequence of instructions that pushes the offsets of word variables X, Y and Z in data segment onto stack? [8+8] 5. (a) Write a program segment that will copy all ASCII characters in string STG that are enclosed by a pair of parentheses to the string MESG and store the number of characters moved in COUNT? [7] (b) Explain the following instructions and their use? i. LODSB ii. CMPSW iii. XLAT

[3+3+3]

6. (a) Show the circuit required to generate the upper and lower I/O strobes in minimum and maximum modes of 8086?

1 of 2

Set No. 2

Code No: RR312001

(b) What is the minimum no. of bus cycles that can occur between the time an interrupt request is recognized and the first instruction in the interrupt service routine is fetched. Show the interrupt acknowledge cycle with a flow chart? [8+8] 7. Interface an 8-bit DAC to 8255 with an address map of 0100H to 0103H. The DAC provides output in the range of +5V to -5V. Write the instruction sequence for the following? (a) For generating a square wave with a peak to peak voltage of 2V and the frequency will be selected from memory location ‘FREQ’. (b) For generating a triangular wave with a maximum voltage of +4V and a minimum of -2V. [8+8] 8. (a) A terminal is transmitting asynchronous serial data at 1200 bd. What is the bit time? Assuming 8 data bits, a parity bit and 1 stop bit how long does it take to transmit one character? (b) Draw necessary circuit to interface 8251 to an 8086 based system with an address 0C0H. Write the sequence of instructions to initialize 8251 for synchronous transmission? (Assume the necessary data) [8+8] ⋆⋆⋆⋆⋆

2 of 2

Set No. 3

Code No: RR312001

III B.Tech I Semester Supplementary Examinations, March 2006 MICROPROCESSORS AND INTERFACING (Production Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Explain the difference between Machine Language, Assembly Language and High Level language. (b) Explain the requirement of a program counter, stack pointer and status flags in the architecture of Intel 8085 Micro process. [8+8] 2. (a) Explain the timing diagram for a write cycle of 8086. (b) Explain the ADDR/STATUS, RD, INT A, OT /R ,DEN and W R signals shown on 8086 timing diagrams. [8+8] 3. (a) Write a program to move a block of memory with out over lapping. (b) Write about the following instructions. i. ii. iii. iv.

ADC AAS IMUL CBW

[8+8]

4. (a) Write a procedure COMPUTE for performing the computation R ← X + Y − 3 The word variables X, Y, R and COMPUTE are in the same code segment. The variables X and Y are defined in data segment D1 SEG. The data segment D2 SEG contains the variable R. Show the necessary definition along with the procedure? (b) Give the definition of a macro RESTORE that will pop the register contents that have been pushed in the order AX, BX, CX, DX, SI and DI? [8+8] 5. (a) Write an instruction sequence that converts 4-digit ASCII coded decimal number into ASCII coded hex equivalent number? (b) Explain string instructions supported by 8086 processor?

[8+8]

6. (a) Give the machine language code for each of the following instructions? i. ii. iii. iv.

IN AL, 52H OUT 0CH, AL OUT DX, AX IN AX, DX

[2+2+2+2]

(b) Discuss the sequence of events during a maskable interrupt and the subsequent return? [8] 1 of 2

Set No. 3

Code No: RR312001

7. (a) Give the advantages of using MOSFET and IGBT over Darlington pair when driving high power load with a port line. (b) Discuss different types of relays for switching larger currents.

[8+8]

8. (a) Why are the two ground pins on an RS 232C connector not just tied together? (b) Explain the RS-232C to TTL interfacing? (c) Write a sequence of instructions to communicate to a modem using 8251 at address 080H. [4+6+6] ⋆⋆⋆⋆⋆

2 of 2

Set No. 4

Code No: RR312001

III B.Tech I Semester Supplementary Examinations, March 2006 MICROPROCESSORS AND INTERFACING (Production Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Explain the difference between Machine Language, Assembly Language and High Level language. (b) Explain the following pins of 8085 Microprocessor. i. ii. iii. iv. v.

RST 5.5 RST 6.5 READY INT A X1 , X2

[6+10]

2. (a) Explain the flag register of 8086. (b) Explain the concept of memory segmentation. (c) Explain, when Queue is failing to speed up the execution.

[6+6+4]

3. (a) Write a program to move a block of memory with out over lapping. (b) Write about the following instructions. i. ii. iii. iv.

ADC AAS IMUL CBW

[8+8]

4. (a) Discuss the difference between intra segment and inter segment procedures? Explain the return procedure in the above cases? Give the sequence of statements for defining the above procedures and return methods? (b) Give the necessary statements to permit the byte variables NUM1, NUM2, NUM3 and NUM4 which are defined in source module 2 to be accessed in source module 1 as if they are defined in source module 1? [8+8] 5. A logic network is having input variables A,B,C,D. The output variables are given W =A.BC + ABC + AD X = AC + BA + AD below. Y = A.B + A.C + D.B Z = ABC + ACD + A.BC The array INPUT 1 contains 10 different combinations of input variables. Write an instruction sequence that determine the outputs for each combination of INPUT 1 array and store the output variables in the string OUTPUT 1. [16] 1 of 2

Set No. 4

Code No: RR312001

6. (a) What is the minimum no. of bus cycles that can occur between the time an interrupt request is recognized and the first instruction in the interrupt service routine is fetched. Show the interrupt acknowledge cycle with a flow chart? (b) Show the complete hardware design to resolve multiple interrupts based on priority using Daisy chain? [8+8] 7. (a) With neat layout, explain how a microprocessor can be used for data acquisition system using A/D converters and D/A converters? (b) Explain the transistor buffer circuit used to drive 7-segment LEDs?

[8+8]

8. (a) Draw the block diagram of 8251 and explain each block? (b) Discuss the serial data transmission standards and their specifications? [8+8] ⋆⋆⋆⋆⋆

2 of 2