Rr321402-microprocessors

Set No. 1

Code No: RR321402

III B.Tech Supplimentary Examinations, Aug/Sep 2008 MICROPROCESSORS (Mechatronics) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Discuss the functions of ALU of 8085. (b) What are the various status flags provided in 8085? Discuss their role. [8+8] 2. (a) Explain the timing diagram for a write cycle of 8086. (b) Explain the ADDR/STATUS, RD, IN T A, OT /R ,DEN and W R signals shown on 8086 timing diagrams. [8+8] 3. (a) Explain the Fixed part and variable part formats of IN and OUT instructions with examples. (b) Write a program to check whether the given string is palindrome or not. [8+8] 4. (a) Define a macro for moving an arbitrary character string that ends with an EOT character from one string of bytes in memory to another? (b) 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? [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) 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) A DAC is interfaced to 8255 with an address map of 0800H to 0803H. Give the hardware design? It is necessary to design a counter type ADC with the same 8255 and DAC using a comparator. Give the necessary hardware? Provide the necessary instruction sequence to store a sample in location ?sampleone?? (b) Using the above hardware write the instruction sequence for successive approximation ADC? [8+8] 8. (a) What is the difference between 20mA current loop and RS232−C standard? 1 of 2

Set No. 1

Code No: RR321402

(b) Explain the necessity of RS232 to TTL interface and draw the circuit? (c) Draw the circuit of TTL to RS232 and explain the necessity of this interface. [5+5+6] ⋆⋆⋆⋆⋆

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Set No. 2

Code No: RR321402

III B.Tech Supplimentary Examinations, Aug/Sep 2008 MICROPROCESSORS (Mechatronics) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) What is a Microprocessor? (b) Explain in detail the pin diagram of 8085 Microprocessor.

[6+10]

2. (a) Explain register to register and register to / from memory with displacement instruction formats with the help of examples. (b) Explain the different type of addressing modes used in 8086.

[8+8]

3. (a) Explain the following instructions with examples i. ii. iii. iv.

XLAT MUL TEST SHL.

(b) Write a program to convert a BCD number to an equivalent Binary number. [8+8] 4. (a) What is the necessity of relocation? Explain the support provided by 8086 for relocation capability (b) Give the address map of interrupt vector address table? Explain with illustration how Int 20H is executed? (c) Explain different ways of passing parameters to subroutine?

[8+4+4]

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 [16] array and store the output variables in the string OUTPUT 1. 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] 1 of 2

Set No. 2

Code No: RR321402

(b) Give the priority of 8086 interrupts, hardware and software? Explain why single step interrupt is having lower priority? [8] 7. (a) Explain the application of stepper motor in microcomputers? (b) Explain with a neat block diagram the working of dual slope ADC? How do you interface the dual slope ADC to microprocessor? Give the required instruction sequence to acquire one sample from ADC? [8+8] 8. (a) What is the difference between 20mA current loop and RS232−C standard? (b) Explain the necessity of RS232 to TTL interface and draw the circuit? (c) Draw the circuit of TTL to RS232 and explain the necessity of this interface. [5+5+6] ⋆⋆⋆⋆⋆

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Set No. 3

Code No: RR321402

III B.Tech Supplimentary Examinations, Aug/Sep 2008 MICROPROCESSORS (Mechatronics) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) What is a Microprocessor? (b) Explain in detail the pin diagram of 8085 Microprocessor.

[6+10]

2. Develop the machine code for following instructions. (a) MOV AX, 000 (b) MOV CX, [2000] (c) MOV [2000], BX (d) MOV AX, BX (e) ADD AX, BX (f) CMP CX, BX. Take 6bit codes for MOV: 100010 ADD: 000000 CMP: 001110 [2+3+3+2+3+3] 3. (a) Explain the following instructions with examples i. ii. iii. iv.

XLAT MUL TEST SHL.

(b) Write a program to convert a BCD number to an equivalent Binary number. [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. Assume that the symbol table starting at location TABLE consists of 100 entries. Each entryhas 80 bytes with the first 8 bytes representing the name field and the remaining 72 bytes representing the information field. Write an instruction sequence to search this table for a given name of 8 characters stored in NAME. If the name is found, copy the associated information into INFO, otherwise, fill INFO with null characters? [16] 6. (a) Give the instruction format of IN and OUT instructions and explain? 1 of 2

Set No. 3

Code No: RR321402

(b) Draw a flow chart showing how a block of N bytes are inputted to memory using programmed I/O transfer? [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 command register and mode register format of 8237 and explain each bit? (b) Show how 8237?s are cascaded to provide more number of DRQ?s and explain the operation? (c) Explain how memory to memory transfer is performed with 8237? ⋆⋆⋆⋆⋆

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[6+5+5]

Set No. 4

Code No: RR321402

III B.Tech Supplimentary Examinations, Aug/Sep 2008 MICROPROCESSORS (Mechatronics) 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) What are the various registers of 8085? Discuss their functions.

[8+8]

2. (a) Explain the Execution unit of 8086. (b) Explain about memory segmentation and Queue.

[8+8]

3. (a) Explain the following Instructions. i. ii. iii. iv.

MOV POP XCHG SAHF.

(b) Write a program to convert a Binary Number to a BCD Number.

[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 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 [16] array and store the output variables in the string OUTPUT 1. 6. (a) Write an instruction sequence that when executed will toggle the state of the read resister bit in OCW3. Assume that the 8259 is located at memory address 00A0H. (b) How do you set or clear the interrupt flag IF? What is its importance in the interrupt structure of 8086? (c) How 8259 can be programmed for rotating interrupt request priorities. Explain? [5+6+5]

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Set No. 4

Code No: RR321402

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

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