EC2304-MICROPROCESSORS AND MICROCONTROLLERS Two Marks Questions With Answers 2014

Anna University, Chennai

DHANALAKSHMI SRINIVASAN INSTITUTE OF RESEARCH AND TECHNOLOGY

SIRUVACHUR PERAMBALUR DEPARTMENT OF ECE

EC2304-MICROPROCESSORS AND MICROCONTROLLERS PART-B QUESTIONS

UNIT-I

1. Explain the internal hardware architecture of 8086 microprocessor with neat diagram.

-Block diagram of 8086

-BIU

-EU

-Memory segmentation

CS, SS, DS, ES

-General Purpose Registers

AX, BX, CX, DX

-Flag Registers

CF, AUF, PF, ZF, TP, OV, IF, DF, SF

2. Write about external memory addressing.

-Block diagram

-8 Bit read at odd & even address

-16 Bit read at odd & even boundary

3. Write about Data transfer schemes.

-Parallel data transfer

-Serial data transfer

4. Explain about interrupt types in 8086.

-Software interrupts

-Single step interrupt

-NMI

-Maskable interrupt

5. Write about Direct memory access in 8086.

-DMA in minimum Mode

-DMA in maximum mode

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UNIT-II

1. Write an ALP to arrange N numbers in ascending order.

DATA SEGMENT

x DW 42H,34H,26H,17H,09H LEN EQU 05

ASCD DB 10 DUP(0) DATA ENDS

CODE SEGMENT

ASSUME CS:CODE,DS:DATA START: MOV AX,DATA

MOV DS,AX

MOV BX,LEN-1

MOV CX,BX

UP1: MOV BX,CX LEA SI,X

UP: MOV AX,[SI]

MOV DX,[SI+2] CMP AX,DX

JB DOWN/JA DOWN

MOV [SI],DX

MOV [SI+2],AX DOWN: INC SI INC SI

DEC BX JNZ UP DEC CX JNZ UP1

MOV AH,4CH INT 21H CODE ENDS END START

2. Write an ALP to find largest number in an array.

DATA SEGMENT

X DW 0010H,0052H,0030H,0040H,0050H

MES DB 10,13,'LARGEST NUMBER AMONG THE SERIES IS $' DATA ENDS

CODE SEGMENT

ASSUME CS:CODE,DS:DATA

START: MOV AX,DATA

MOV DS,AX MOV CX,05H LEA SI,X MOV AX,[SI] DEC CX

UP: CMP AX,[SI+2] JA CONTINUE MOV AX,[SI+2]

CONTINUE:ADD SI,2

DEC CX JNZ UP AAM

ADD AX,3030H

MOV BX,AX

MOV AX,09H LEA DX,MES INT 21H

MOV DL,BH MOV AH,02H INT 21H

MOV DL,BL

INT 21H

MOV AH,4CH

INT 21H CODE ENDS END START

3. Write about Data transfer group and Logical instruction group of 8086.

-Data transfer instructions

MOV <d>, <s> XCHG <d>, <s> XLAT

PUSH<s> POP <d>

-Logical instructions

AND <d>, <s> OR <d>, <s> XOR <d>, <s> NOT <d>

NEG <d> CMP<d>,<s>

TEST <d>,<S>

4. Write about Assembler directives of 8086.

-SEGMENT

-ENDS (END SEGMENT)

-CODE SEGMENT

-END (END PROCEDURE)

-ASSUME

-DB (DEFINE BYTE)

-DD (DEFINE DOUBLE WORD)

-DQ (DEFINE QUADWORD)

-DT (DEFINE TEN BYTES)

-LENGTH

-OFFSET

-PTR (POINTER)

-BYTE PTR

-EVEN (ALIGN ON EVEN MEMORY ADDRESS)

5.Write about operand addressing modes of 8086.

-Register addressing mode ,

-Immediate addressing mode,

-Direct addressing mode,

-Indirect addressing mode,

- Base Plus Index addressing mode,

-Register Relative addressing mode,

-Base Relative Plus Index addressing mode.

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Unit-III

1. With neat block diagram explain the 8255 programmable peripheral interface and its

Operating modes.

` -8255 block diagram

-Mode0-Basic Input/output

-Mode 1-Strobed Input/Output

-Mode 2-Strobed Bidirectional bus

-Configuring 8255

-Interfacing 8255

2. Draw and explain the block diagram of 8254 programmable interval timer. Also explain the various modes of operation.

-Interfacing 8254 with 8086 block diagram

-Counter 0

- Counter 1

- Counter 2

3. Explain the need for sample and hold circuit and multiplexer.

-S&H circuit placed after the multiplexer

-Mux placed after the S&H circuit connections

4. Explain 8279 keyboard /display controller with neat block diagram.

-Internal block diagram of 8279

-Keyboard section

-Display section

-Software commands

-Interfacing 8279

5. Describe the architecture and working of 8253 timer.

Similar operation of 8254

6. Draw and explain the block diagram of A to D converter.

-ADC chip configuration

-Asynchronous mode

- Synchronous mode

-Interrupt mode

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UNIT-IV

1. Explain the architecture of 8051 with its diagram.

-Block diagram of 8051

-Memory organization

-Program memory

-Data memory

-Special function registers

2. Write about operating modes for serial port of 8051 microcontroller.

-Port 0 configuration

-Simple I/O operation

-External memory interface

-Port 1

-Port 2

-Port 3

3. Write about the instruction set of 8051 microcontroller.

-Data transfer instructions

-Arithmetic instructions

-Logic instructions

-Control transfer instructions

4. Explain about the operand addressing of 8086.

-Register addressing

-Direct addressing

-Indirect addressing

-Immediate addressing

-Base plus index register indirect addressing

5. Explain the interrupt structure of 8051 microcontroller.

-INT0

-INT1

-TF0

-TF1

-RI/TI

UNIT-V

1. Draw and explain the block diagram of traffic light control system.

-Traffic light FSM Interface signals

-Switching circuit

-Operation sequence

2. Draw the diagram to interface a stepper motor with 8051 microcontroller and explain its operation.

-

-Step angle:

Step angle is defined as the minimum degre of rotation with a single step. No of steps per revolution = 360° /step angle

Steps per second = (rpm x steps per evolution) /60

Example: step angle = 2°

No of steps per revolution = 180

Switching Sequence of Motor:

This can be done by sending a bits sequence to one end of the coil while the other end is commonly connected. The bit sequence sent can make either one phase ON or two phases ON for a full step sequence or it can be a combination of one and two phase ON for half step sequence.

Two Phase ON

One Phase ON

3. Explain how interrupts are handled in 8051.

- Interrupt Sources

- External Interrupts

- Internal Interrupts

- Enabling Interrupts

- Interrupt Priorities

4. Draw and explain the Washing machine control using 8051.

-Washing cycle

-Control system design

-Software