Embedded Systems Design Lecture 1 -Basic Concepts

What is an computing system?

- a system of one or more computers and associated software with common storage

Components of CPU and Their Functions

1.Control Unit (CU) 2.Arithmetic Logic Unit (ALU) 3.Registers 4.Cache 5.Buses 6.Clock

High-performance

A CLASSIFICATION OF EMBEDDED • Dedicated board-level hardware • Task intensive, RTOS-based • Low-volume, high cost • High maintenance

Small

A CLASSIFICATION OF EMBEDDED • MCU-based, low component count • Large volume • Single tasked • Low-cost, maintenance-free

Distributed

A CLASSIFICATION OF EMBEDDED • Multi-chip, board-level •Multi-tasked • Medium volume & cost • Maintainable, upgradeable

Complex instruction set computing

A processor like CISC has the capacity to perform multi-step operations or addressing modes within one instruction set. It is the CPU design where one instruction works several low-level acts. For instance, memory storage, loading from memory, and an arithmetic operation.

CISC

Complex instruction set computing

It contains a large memory semiconductor memories like cache and RAM. it also contains secondary storage like hard disks etc.

Computing Systems

It is designed to perform multiple tasks as per requirement.

Computing Systems

It is designed using a microprocessor as the main processing unit.

Computing Systems

It is mostly costlier compared to the embedded systems.

Computing Systems

It requires huge number of peripheral devices and their controllers.

Computing Systems

The Operating system and other software for the general purpose computers, are normally complicated and occupy more memory space.

Computing Systems

Composition of Embedded Software

Depending on the complexity of device, all embedded solutions use microcontrollers, microprocessors, or other special-purpose processing units like digital signal processors (DSP) at the heart of their dedicated hardware.

Hardware Components

Electronics Infrastructure -CPU -Memory -I/O Subsystem

It is cheaper as it requires less no of peripheral devices and their controllers are microcontroller chip itself.

Embedded Systems

It is cheaper compared to a computer.

Embedded Systems

It is designed to perform a particular predefined task.

Embedded Systems

It is mostly designed using a microcontroller as the main processing unit.

Embedded Systems

It uses semiconductor memories, but does not require secondary memories like hard disk, CD. it sometime has special memory called flash memory.

Embedded Systems

The operating system(mostly RTOS i.e. Real Time Operating System) and other software occupy less memory space.

Embedded Systems

Instruction fetches

Fetch the instruction from the main memory or cache.

I/O Devices

Hardware Components -Communication ports -User interfaces -Sensors & actuators -Diagnostics support -System controllers -Power management -Specialized ASICs

Memory

Hardware Components -Program Memory -Data Memory

Central Processing Unit

Hardware Components -Registers, ALU, CU

Embedded System Structure

Hardware Components Software Components

Operand fetch

If the execution of the instruction requires operand then the processor fetches operand from the main memory or cache.

What is Instruction Pipelining?

Instruction fetches Instruction decoding Operand fetch Instruction Execution Operand Store

Characteristics of embedded systems?

Perform a single function Form part of large system Are expected to work with minimal or no human interaction Reactive, real-time operation Tightly constrained

RISC

Reduced instruction set computing

The CPU architectural are:

Reduced instruction set computing (RISC). Complex instruction set computing (CISC).

Single Board Computers

SBC

System-on-a-Chip

SOC

are an entire computer built on a single circuit board. It also has a memory, microprocessor, and input-output features needed for a functional computer.

Single Board Computers (SBC)

are standard products that can be utilized to advance the results for different industries.

Single Board Computers (SBC)

A CLASSIFICATION OF EMBEDDED

Small Distributed High-performance

System Tasks

Software Components -Actions making use of system resources

System Kernel

Software Components -Manages system resources -Coordinates task services

Services

Software Components -Routines performing specific tasks

Software Components

System Functionality -Firmware -Operating System -Application Programs

Software Components

System Tasks System Kernel Services

incorporates plenty of system components into a single silicon chip.

System-on-a-Chip (SOC)

is widely used across the embedded industry because of the features, such as the computational quality, low power consumption, and small form factor.

System-on-a-Chip (SOC)

Embedded System implementation techniques

System-on-a-Chip (SOC) Single Board Computers (SBC)

Instruction decoding

The processor interprets instruction and determines the operation that has to be performed.

Instruction Execution

The processor performs the desired operation.

Operand Store

The result of execution is stored.

Basic Elements of an Embedded System

User Interface Embedded Computer Input Variables Software output Variables Hardware Link to other Systems

The embedded software components

User interface Input/output interfaces Processor Memory Timers Serial communication ports Circuits to connect to other systems.

Microcontrollers

by comparison, place greater emphasis on additional hardware modules that allow the device to control a system rather than simply execute instructions and store data

Both microprocessors and microcontrollers

function as small, highly integrated computer systems, but they may serve different purposes.

CPU architecture

he architecture of the Central Processing Unit (CPU) operates the capacity to function from "Instruction Set Architecture" (ISA).

Reduced instruction set computing

is a Central Processing Unit design strategy based on the vision that a basic instruction set gives great performance when combined with a microprocessor architecture that has the capacity to perform the instructions by using some microprocessor cycles per instruction.

Microprocessor

is a device that implements all of a processor's functionality within a single integrated circuit.

What is an Embedded Systems?

is a microprocessor- or microcontroller-based system of hardware and software designed to perform dedicated functions within a larger mechanical or electrical system.

What Is a Microcontroller?

is an integrated circuit (IC) device used for controlling other portions of an electronic system, usually via a microprocessor unit (MPU), memory, and some peripherals. These devices are optimized for embedded applications that require both processing functionality and agile, responsive interaction with digital, or electromechanical components.

The term "processor"

is used to identify a system that consists of a central processing unit and (optionally) some memory.