Embedded System

Embedded System• Any device that include a computer but is not itself a general purpose computer.• Hardware and Software of some large system and expected to function without human intervention• Respond, monitor, control external environment using sensors and actuators.

Embedding a ComputerCPU

Output

input

Memory

Automobile Embedded SystemToday’s high-end automobile may have 100 microprocessors.– 4 bit microcontroller checks seatbelt.– Microcontroller run dashboard devices.– 16/32 bit microprocessor control engine

Characteristics of Embedded System• Sophisticated functionality.• Application dependent processors• Restricted memory.• Embedded systems have to be efficient.• These systems are dedicated towards a certain application.• Many embedded systems are hybrid systems in the sense that they include analog and digital parts.• Many embedded systems must meet real-time constraints.• Low Power

Real Time Operation• Hard Real Time• Soft Real Time

Vending Machine8-bit microprocessors.

Nasa’s Mars Sojourner Rover8 Bit Intel 80c85 Microprocessor

GPS Receiver 16 bit Microprocessor

Mp3 Player 32 bit RISC Microprocessor

DVD Players32 bit RISC Microprocessor

Sony Aibo ERS-110 Robotic Dog64- bit MIPS RISC

Type of Embedded System1. Similar to General Computing

- PDA, Video games, Set-top Boxes, Automatic teller m/c2. Control Systems- Feed-back control of real time system.-Vehicle engines, flight control, nuclear reactors.3. Signal Processing- Radar, DVD Player, Mp3 Players4. Communication & Networking- Cellular Phones, Internet appliances.

ArchitectureFPGA Memory

A/D CPU D/ASensor Actuator

Software

Human Interface

Diagnostics Tool

How to Implement an Embedded SystemHardware

- Processing Element- Peripherals * Input & Output* Interfacing Sensors & Actuators- Memory- BusSoftware-System Software-Application Software

Processing elements• General Purpose Microprocessor & Microcontroller• DSP• Application Specific Processor• System- on – Chip (SOC)

Challenges in Embedded System Design• How much hardware do we need?- What is word size of the CPU? Size of Memory?• How do we meet our dead lines?- Faster hardware or cleverer software?• How do we minimize power?-Turn off unnecessary Logic. Reduce memory access.

Embedded HardwareReceive input --- Process it --- Provide OutputMicroprocessor & Microcontrollers.- Energy Efficiency- High Code density.

Microprocessors

• CPU for Computer• No RAM,ROM, I/O on chip itself• Example Intel’s x86, Motorola’s 680x0

CPUGeneral Purpose

Microprocessor

RAM ROM I/O Timer Serial Port

What is Microcontroller • Basically a microcontroller is a device which integrates a large number of components of a microprocessor system onto a single microchip.• A microcontroller combines on to the same microchip- The CPU core- Memory (both ROM and RAM)- Some parallel digital I/O & more.

Microcontroller

BUS

CPU Memory I/O

Components of a Microcontroller• A Timer module to allow the microcontroller to perform task for certain time periods.• A Serial I/O ports to allow data to flow between the microcontroller and other devices such as a Pc or another microcontroller.• An ADC to allow the microcontroller to accept analog input data to processing.

Microcontroller BlockProgram Memory

Core

Parallel port

Data Memory

Parallel Port

Parallel port

Serial port

Timer

Serial port

Why Microcontroller?• Low cost, Small packaging• Low power consumption• Programmable , re-programmable• Easy integration with circuits• For applications in which cost, power and space are critical.• Single purpose.