(SEM VI) THEORY EXAMINATION 2021-22 MICROCONTROLLER & EMBEDDED SYSTEM DESIGN

MICROCONTROLLER & EMBEDDED SYSTEM DESIGN (KEC061)

Section-wise Detailed Answers – B.Tech Semester VI

SECTION A

(Attempt all questions – descriptive answers)

Q1(a) Describe the term Microprocessor and its applications

A microprocessor is a programmable electronic device that performs arithmetic, logical, and control operations by executing instructions stored in memory. It acts as the central processing unit of a system but requires external memory and peripherals to function completely. Microprocessors are widely used in computers, laptops, servers, industrial control systems, automation equipment, and communication devices where high processing power and flexibility are required.

Q1(b) Define the working of EEPROM

EEPROM stands for Electrically Erasable Programmable Read-Only Memory. It is a non-volatile memory that retains stored data even when power is removed. Data stored in EEPROM can be erased and rewritten electrically without removing the chip from the circuit. It is commonly used to store configuration settings, calibration values, and firmware parameters in embedded systems.

Q1(c) Describe instruction set for any microcontroller

An instruction set is a collection of machine-level commands that a microcontroller understands and executes. It includes data transfer instructions, arithmetic and logical operations, control flow instructions, bit manipulation commands, and input-output instructions. For example, in the 8051 microcontroller, instructions such as MOV, ADD, SUB, JMP, and SETB control internal registers, memory, and external devices.

Q1(d) Differentiate between Memory Mapped and I/O Mapped peripherals

In memory-mapped I/O, peripherals share the same address space as memory, allowing standard data movement instructions to access devices. In I/O-mapped peripherals, a separate address space is used exclusively for I/O operations, and special instructions are required to access peripherals. Memory-mapped I/O offers flexibility but consumes memory space, while I/O-mapped I/O conserves memory addresses.

Q1(e) Define the term Timer and its applications

A timer is a hardware peripheral that counts clock pulses to measure time intervals or generate delays. Timers are widely used for generating accurate delays, event counting, frequency measurement, PWM generation, and scheduling tasks in real-time systems. Timers play a crucial role in embedded system timing control.

Q1(f) Describe the Data Acquisition Process

The data acquisition process involves collecting real-world physical signals such as temperature, pressure, or voltage and converting them into digital form for processing. Sensors convert physical parameters into electrical signals, which are then conditioned, sampled, converted using an ADC, and processed by the microcontroller. Data acquisition is essential in monitoring and control applications.

Q1(g) Describe Interfacing process in any processor

Interfacing is the process of connecting external devices such as sensors, displays, and communication modules to a processor so that data can be exchanged. It involves hardware connections, address decoding, and software programming to control data transfer. Proper interfacing ensures compatibility, timing synchronization, and reliable communication.

Q1(h) Define the term Wireless Networking

Wireless networking refers to communication between devices without physical connections, using electromagnetic waves. Technologies such as Wi-Fi, Bluetooth, ZigBee, and cellular networks enable wireless data transmission. Wireless networking provides flexibility, mobility, and ease of deployment in embedded and IoT systems.

Q1(i) Define the term IoT (Internet of Things)

The Internet of Things is a network of interconnected physical devices embedded with sensors, processors, and communication modules that collect and exchange data over the internet. IoT enables smart automation, remote monitoring, and data-driven decision-making in applications such as smart homes, healthcare, agriculture, and industrial automation.

Q1(j) Describe the applications of Bluetooth in Microcontrollers

Bluetooth is a short-range wireless communication technology widely used in microcontroller-based systems. Applications include wireless data transfer, sensor communication, smart devices, wearable electronics, home automation, and mobile-controlled embedded systems. Bluetooth enables low-power and secure connectivity.

SECTION B

(Attempt any three – detailed explanations)

Q2(a) Block diagram of 8051 Microcontroller

The 8051 microcontroller consists of a central processing unit, program memory, data memory, I/O ports, timers, serial communication unit, and interrupt controller. The CPU executes instructions stored in program memory, while data memory stores temporary variables. I/O ports interface with external devices. Timers generate delays and measure time, while serial communication enables data exchange. The interrupt system handles asynchronous events efficiently.

Q2(b) Addressing Modes of MSP430 Microcontroller

The MSP430 microcontroller supports multiple addressing modes that provide flexibility and efficiency. These include register mode, indexed mode, symbolic mode, absolute mode, indirect register mode, and immediate mode. Addressing modes determine how operands are accessed during instruction execution, enabling optimized code and low power operation.

Q2(c) Difference between Timer and Real Time Clock Applications

A timer measures short time intervals and generates delays based on clock pulses. It is commonly used for task scheduling, PWM generation, and event counting. A Real-Time Clock keeps track of actual time including seconds, minutes, hours, date, and year. RTCs are used in digital clocks, data logging, and time-stamping applications.

Q2(d) Operations and working of USB protocol communication

USB protocol enables standardized communication between a host and peripheral devices. It supports data transfer, device enumeration, power supply, and plug-and-play operation. USB communication involves endpoints, descriptors, and packet-based data transfer. It is widely used for interfacing storage devices, input devices, and communication modules.

Q2(e) Block diagram of Wi-Fi connectivity protocol

Wi-Fi protocol includes a radio transceiver, baseband processor, MAC layer, and network interface. The transceiver handles RF communication, while the baseband processor manages modulation and demodulation. The MAC layer controls data framing and addressing. Wi-Fi enables high-speed wireless communication for IoT and embedded systems.

SECTION C

(Attempt one part from each set – detailed answers)

Q3(a) Process of generating PWM signal in microcontrollers

PWM generation involves using timers to create a periodic signal whose duty cycle can be varied. The timer counts clock pulses and compares the count value with a predefined threshold. When the count matches the threshold, the output toggles. By changing the threshold value, the duty cycle is adjusted. PWM is used for motor control, brightness control, and power regulation.

Q3(b) Different peripherals interfaced to Microcontrollers

Microcontrollers interface with peripherals such as LCDs, keypads, sensors, ADCs, DACs, motors, communication modules, and memory devices. These peripherals extend system functionality by enabling input, output, communication, and control operations.

Q4(a) Block diagram of MSP430 Microcontroller

The MSP430 microcontroller consists of a CPU, flash memory, RAM, clock system, timers, ADC, communication interfaces, and low-power management unit. It is designed for ultra-low-power applications and efficient real-time processing.

Q4(b) Interrupts in MSP430 and their programming

Interrupts allow MSP430 to respond to external or internal events without continuous polling. Interrupt sources include timers, ADC, communication modules, and external pins. Programming interrupts involves enabling interrupt flags, setting priority, and writing interrupt service routines. Proper use of interrupts improves efficiency and power management.

Q5(a) DMA operation and associated modes in MSP430

Direct Memory Access allows data transfer between peripherals and memory without CPU intervention. MSP430 DMA supports multiple channels and modes such as single transfer, block transfer, and repeated transfer. DMA improves system performance and reduces power consumption.

Q5(b) Watchdog Timer applications, modes, and control words

The Watchdog Timer monitors system operation and resets the microcontroller if a fault occurs. It operates in watchdog mode or interval timer mode. Control words configure timeout duration and 
behavior. Watchdog timers enhance system reliability.

Q6(a) SPI interfacing process and modes with MSP430

SPI is a synchronous serial communication protocol using master-slave architecture. MSP430 supports SPI modes based on clock polarity and phase. Interfacing involves configuring registers, selecting data rate, and managing chip select signals. SPI is used for high-speed data transfer.

Q6(b) I2C interfacing process and modes with MSP430

I2C is a two-wire serial communication protocol using SDA and SCL lines. MSP430 supports master and slave modes. Addressing, start/stop conditions, and acknowledgments control data transfer. I2C is widely used for sensor and memory interfacing.

Q7(a) Working of CC3100 user API for connecting sensors

CC3100 is a Wi-Fi network processor that enables IoT connectivity. The user API provides functions for initialization, network configuration, data transmission, and sensor communication. It simplifies IoT application development.

Q7(b) ZigBee communication modes and applications

ZigBee supports star, tree, and mesh network topologies. It offers low power consumption, secure communication, and scalability. Applications include home automation, industrial monitoring, smart lighting, and wireless sensor networks.