Embedded Systems

Question 1

Embedded systems: definition

Answer 1

computer system with a dedicated function within a larger system, often with real-time computing constraints. It is embedded as part of a complete device

Question 2

ES Characteristics

Answer 2

small size and weight
operate in a harsh environment
reactive and real time
distributed but interconnected
power concerns
application and domain specific

Question 3

ES: Differences among them for

Answer 3

funcionality: fixed versus programmable
user interface: from 0 to gui

Question 4

how ES work

Answer 4

1. sensor reads imput
2. converter makes input processor-readable
3. data trasmitted though communication ports between processor and peripherals
4. Processor interprets data with minimal software

Question 5

ES commonalities

Answer 5

low cost, low power consuming
part of a complete device
composed of:
-sw and firmware (sometimes RTOS)
-hardware

Question 6

ES: hardware parts

Answer 6

sensors
power supply
memory
communication ports/interfaces
converters
actuators
processor

Question 7

ES: processor types

Answer 7

microprocessors: uses separate integrated circuits for memory/peripherals. less integration on the processor= solving different tasks, more support circuitry

microcontrollers: peripheral interfaces + memory, for single task

Question 8

ES: processor advancement

Answer 8

system on chip: multiple processor and interfaces onto a single chip. compact (mobile devices) and efficient (less distance among components). but complex, costly, changing indivudal parts not flexible

Question 9

ES function

Answer 9

give computational resources to other devices.
-critical for IOT
-for real time operating systems: designed to process date as it comes, stright time constraints
-many fields: industrial machines, automobiles, medical equipment, household application, mobile devices

Question 10

types of ES

Answer 10

based on performance and functional requirements:
-real time: output needed in a specific time interval
-stand alone: only one without necessarily a host
-networked: provide other systems with output
-mobile: portable

based on microcontroller performance:
-small scale
-medium scale
-sofisticated

Question 11

ES common feature

Answer 11

very large scale integration (VLSI) = embedding hundreds of thousands of transistors onto acceap
complex functionalities and efficent solutions (SoC)
ultra

Question 12

ES ARCHITECTURES

Answer 12

• simple control loop
• • sequential execution of tasks
• • at each iteration a subroutine is called to perform a specific hw/sw function
• • for straightforwad apps
• • avd: easy implementation
• • dis: not for time critical tasks
• interrupt-controlled system
• • main loop + Interrurrupt Service Routines (IRS)
• • main loop used for general tasks, ISR for time critical events
• • for applications that require prompt response to secific events
• • adv: efficient CPU use + responsiveness for critical events
• • dis: complex
• cooperative multitasking
• • API manages tasks
• • Each task runs until completion/competion of subtask to allow multitasking
• • for apps where tasls should cooperate and are not time critical
• • adv: simplifies task management + no need for complex synchronization
• • dis: no time-critical tasks, one task can monopolize cpu
• preemptive multitasking/multithreading with real time operating system
• • RTOS manages tasks basedon priority and time-slicing
• • Task scheduling depends on priority
• • for complex apps with time constraints
• • adv: timely execution of high priority tasks + system’s reliability
• • dis: system’s complexity + resource consumption + careful design needed