Advantages and Disadvantages of Status-Polling and Interrupt-Driven I/O

Q1 State the advantages and disadvantages of Status-polling I/O and Interrupt-driven I/O.

In program controlled I/O, the CPU repeatedly checks a status flag to achieve the required synchronization between the CPU and the input device. The program enters a wait loop in which it repeatedly tests the device status. During this period, the CPU is not performing any useful computation. In interrupt I/O, other tasks can be performed while the CPU waits for an I/O device to become ready. The CPU allows

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Understanding the 555 Timer: Astable and Monostable Multivibrator Applications

The 555 Timer IC

The 555 timer IC is a versatile device used in various timing and waveform generation applications. This article explains its block diagram and applications as both an astable and monostable multivibrator.

Block Diagram of 555 Timer

The internal block diagram of the 555 timer consists of the following components:

  • Two Comparators: These compare input voltages with two reference voltages, typically 1/3 and 2/3 of the supply voltage.
  • Flip-Flop: The comparators’ outputs set and reset the
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Assembly Language Programs

num1 db 00h                                  num1 dw 1234h 
num2 db 00h                                  num2 dw 5678h 
data ends                                         res dw 00h 
code segment                                  data ends 
assume cs:code,ds:data                    code segment 
start:                                                 assume cs:code, ds:

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Induction Motor Fundamentals: Types, Operation, and Applications

Induction Motor Fundamentals

Stator Winding and Magnetic Field

The stator winding of a three-phase induction motor is designed to create a rotating magnetic field. This is achieved by distributing the coils in a specific way and feeding them with a balanced three-phase supply. The goal is to optimize the use of coils, generate a strong magnetic field, and achieve a sinusoidal field distribution in the air gap for efficient operation.

Rotor Types and Induced Currents

Induction motors typically use two

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Communication Systems and Signal Processing Problems

1) Communication Systems and Signal Processing Problems

  • 1) Armstrong FM Modulator Design

    The total amount of frequency multiplication required is: 75 / 1.5 = 50. If the narrowband FM signal is input to a frequency multiplier with factor 50, then the carrier frequency gets converted to 5 MHz. So at the output of the frequency multiplier, we need a mixer, which shifts the carrier frequency by 99 MHz to 104 MHz.

  • 2) Binary Channel Decision Rule

    (a) Since 0 and 1 are sent with equal probabilities, the optimal

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Types of Motor Controllers for Different Applications

Applications.DC: They are directly connected to batteries in small applications. Or high torques are needed in big industrial applications. Connected to batteries: toys/car whippers. Old elevators/cranes/deployable bridges.


Used when high precision at positioning, speed, or acceleration is needed. Also when high torques at low frequencies. Short and repetitive working cycles. CNC milling machines-close loop/Labeling machine-close loop/Printing presses-open loop.


Long working cycles where

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