R05320202-microprocessors-and-micro-controllers

Set No. 1

Code No: R05320202

III B.Tech Supplimentary Examinations, Aug/Sep 2008 MICROPROCESSORS AND MICRO CONTROLLERS (Electrical & Electronic Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Discuss the following interface signals of 8086 in minimum mode i. DMA interface signals ii. Interrupt signals (b) Discuss the following Data Transfer instructions i. ii. iii. iv. v.

IN MOV POP XLAT LAHF.

[8+8]

2. (a) Write an ALP to find the smallest of a given array of 16 bit numbers? ( assume suitable array length) (b) Define a MACRO ”SQUARE” that calculates the Square of number. [10+6] 3. (a) Explain the steps involved in the Interfacing of an I/O device (b) Explain various methods of interfacing of I/O devices. 4. Explain various operating modes of 8259 PIC.

[6+10] [16]

5. (a) Explain the pin structure of RS232C and also discuss about voltage and current specifications of RS 232C. (b) Describe important features of 8251 USART.

[8+8]

6. (a) Draw the architectural diagram of 8051 microcontroller and explain in detail about each block. (b) Explain the basic differences between a microprocessor and a microcontroller. [10+6] 7. (a) Write 8051 program to generate 2 kHz square waves on pin P1.0 of port 1 using Timer interrupt. (b) Write 8051 program to receive a serial byte through RxD.

[8+8]

8. Give the hardware and software details of 4 × 4 matrix keyboard interfaced to 8051. [16] ⋆⋆⋆⋆⋆ 1 of 1

Set No. 2

Code No: R05320202

III B.Tech Supplimentary Examinations, Aug/Sep 2008 MICROPROCESSORS AND MICRO CONTROLLERS (Electrical & Electronic Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Discuss the minimum mode memory control signals of 8086? (b) Explain the write cycle operation of the microprocessor with a neat timing diagram in maximum mode. [8+8] 2. (a) Explain the following Assembler Directives i. ii. iii. iv. v.

ASSUME ENDS EVEN OFFSET PUBLIC

(b) Write an ALP to perfom the division operation on two 16 bit Hex numbers. [10+6] 3. Interface 16-bit 8255 ports with 8086 . The address of Port A is F0H.

[16]

4. (a) Explain pin diagram of 8259 PIC (b) Explain the interrupt sequence in 8086 system.

[10+6]

5. (a) Give the specifications of RS232C? (b) Explain about line driver and line receiver used in serial communication? (c) Give the status register of 8251 and explain each bit.

[4+6+6]

6. (a) Draw the oscillator circuit and also draw the 8051 timing diagram. (b) Discuss in detail about parallel I/O ports in 8051 micro controller and explain how these ports are accessible for specific applications. [8+8] 7. (a) Give the sequence of events that takes place when the interrupt occurs in 8051. (b) Draw the bit formats of IE and IP registers of 8051?

[8+8]

8. (a) Explain with a neat diagram how push button and LED can be connected to 8051 (b) Mention any application of electromagnetic relay and explain how a electromagnetic Relay is connected to a 8051 microcontroller with diagram. [8+8] ⋆⋆⋆⋆⋆

1 of 1

Set No. 3

Code No: R05320202

III B.Tech Supplimentary Examinations, Aug/Sep 2008 MICROPROCESSORS AND MICRO CONTROLLERS (Electrical & Electronic Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. What is a machine cycle? Explain the basic 8086 system timing with a neat timing diagram. [16] 2. Write an 8086 Assembler program to decide the parity of a given number? If the parity is even, set DL to 00H, else set DL to 01H. The given number may be a multibyte number with a maximum length of 8 bytes. [16] 3. Interface a 4 x 4 key board with 8086 using 8255 and write an ALP for detecting the key closure and return the key code in AL. The debouncing period for a key is 10 ms.Use software key debouncing technique. DEBOUNCE is an available 1 ms delay routine. [16] 4. (a) What are the registers available in 8257? What are their functions (b) Explain the functions of following signals of 8257 i. ii. iii. iv.

HLDA AEN MARK MEMR.

[8+8]

5. (a) Explain why serial data transfer is mostly preferred over parallel data transfer. Give reasons. (b) Distinguish between data formats used for Synchronous and Asynchronous serial data transfer modes. [8+8] 6. (a) Draw the oscillator circuit and also draw the 8051 timing diagram. (b) Discuss in detail about parallel I/O ports in 8051 micro controller and explain how these ports are accessible for specific applications. [8+8] 7. (a) Discuss in detail about serial port operation in 8051 microcontroller. (b) Discuss about various modes of operations of timer in 8051.

[8+8]

8. Give the hardware and software details of interfacing of 7-segment displays to 8051 Microcontroller with time-multiplexing and display select mechanism. [16] ⋆⋆⋆⋆⋆

1 of 1

Set No. 4

Code No: R05320202

III B.Tech Supplimentary Examinations, Aug/Sep 2008 MICROPROCESSORS AND MICRO CONTROLLERS (Electrical & Electronic Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. Explain string manipulation instructions of 8086 examples?

[16]

2. (a) Write short notes on Assembler? (b) Write an assembly language program to arrange a list of numbers in ascending order (with out using the assembler)? [6+10] 3. Interface 8255 with 8086 to work as an I/O port. Initialise Port A as output port, Port B as input port and port C as output port. Port A address should be 0740H. Write a program to sense switch positions SW0-SW7 connected to port B. The sensed pattern is to be displayed on port A to which 8 LEDs are connected, while PORT C Lower half displays number of on switches out of the total 8 switches. [16] 4. Interface DMA controller 8257 with 8086 so that the channel 0 DMA address register has an I/O address 80 H and the mode set register has an address 88H. Initialize 8257 with a normal priority, TC stop and non extended write. Autoload is not required . Write an ALP to move 2 KB of data from a peripheral device to memory address 2000:5000H with the above initialization. [16] 5. (a) Write an 8086 instruction sequence for transmitting the characters using 8251 on a polled basis. (b) Write an 8086 instruction sequence for receiving 100 characters using 8251 on a polled basis and store them in memory at location 2050H. [8+8] 6. (a) Give the features of 8051 microctroller. (b) Explain the following pins of 8051. i. ii. iii. iv.

AD0 - AD7 T0 and T1 INT0 and INT1 TxD and RxD

[8+8]

7. (a) Write 8051 program as an example of interrupt call to a routine, timer 0 is used in mode 0 to overflow and set the timer 0 interrupt flag. When the interrupt is generated, the program vectors to the interrupt routine, resets the timer 0 interrupt flag, stops the timer, and returns. (b) Discuss the bit format of IP register of 8051?

1 of 2

[8+8]

Set No. 4

Code No: R05320202

8. (a) Explain with a neat diagram how push button and LED can be connected to 8051 (b) Mention any application of electromagnetic relay and explain how a electromagnetic Relay is connected to a 8051 microcontroller with diagram. [8+8] ⋆⋆⋆⋆⋆

2 of 2