Introducing Embedded Systems and the Microcontrollers Chapter TWO

Outline Definition of Embedded Systems Examples Computer Essentials Microprocessors and Microcontrollers PIC Microcontrollers 12 Series PIC

Definition of Embedded Systems Embedded system: is a system whose principal function is not computational, but which is controlled by a computer embedded within it.

An Overview on the Design of Embedded Mixed-Signal Systems Types of embedded applications and their characteristics (interfaces, functionality, and design requirements) CPUs used in embedded systems (microprocessors and microcontrollers, DSP, VLIW processors, and reconfigurable architectures) Top-down design flow based on design refinement and circuit modeling The evolution of the embedded systems market Illustrating example for a embedded mixed-signal system design ©Alex Doboli 2006

Sensing and actuation devices in embedded applications ©Alex Doboli 2006

Embedded Applications Signal sensing/data acquisition – data processing & data storing – actuation – data communication (networking) ©Alex Doboli 2006

Embedded Applications Networking, intelligent control ©Alex Doboli 2006

Embedded Applications Networking ©Alex Doboli 2006

Examples: Refrigerator

Examples: Car Door

Examples: Electronic Ping-pong

Examples: Derbot Autonomous Guided Vehicle

Examples: Derbot Autonomous Guided Vehicle

Computer Essentials

Computer Essentials Instruction Sets Memory Types CISC: Complex Instruction Set Computer RISC: Reduced Instruction Set Computer Memory Types Volatile: Random Access Memory (RAM) Non-volatile: Read Only Memory (ROM)

Von Neumann and Harvard Computers Dr. Gheith Abandah

Microprocessors and Microcontrollers The microprocessor is a processor on one silicon chip. The microcontrollers are used in embedded computing. The microcontroller is a microprocessor with added circuitry. Dr. Gheith Abandah

Types of Embedded Applications (1) A. Embedded controllers Supervise and adjust the behavior of the monitored entities Fan controller, pacemakers, robot arm controller, Low/medium computational complexity, real-time, safety-critical, accurate sensing, low cost B. Specialized interfaces Interfacing to powerful computers Supply the missing hardware Relieves the computer from interfacing jobs: data conversion, encoding/decoding, encryption/decryption, etc. Small cost & size, low/medium computational complexity, fast throughput, low energy consumption Data acquisition, networking cards, capacitive sensing, mouse ©Alex Doboli 2006

Types of Embedded Applications (2) C. Application-specific coprocessors Customized data intensive processing: DSP, multimedia, graphic processors, image processing, video processing Relieves CPU from computationally intensive tasks High speed, low power consumption, low cost & size D. Networks of embedded systems Automotive applications: networked embedded microcontrollers, sensors, actuators Wireless networks, sensor networks Low cost, small size, reduced memory, low energy consumption, variety of sensors/actuators Communication protocols, data routing, data aggregation, control, scalability, self-organizing, autonomous ©Alex Doboli 2006

Data Flow in an Embedded System ©Alex Doboli 2006

Summary of Embedded Systems characteristics System types Sensing Actuation Data communic. Data processing Requirements & constraints Controllers Wide range - control Cost, accuracy, timing, safety Specialized interfaces Various speed Conversion,formatting,encoding Cost,size,accuracy,timing, power consumpt. Co-processors High-speed Data-intensive customized Cost, size, speed, power consumpt. Networks of embedded systems Control, conversion, encoding Cost, size, safety, power consumpt. ©Alex Doboli 2006

I/O Interfaces Analog and digital signals Voltage, current, charge, frequency, phase Thermistors, theromocuples, pressure sensors, velocity sensors, strain gauges, etc. Signal conditioning circuits, analog multiplexers, ADC, DAC, comparators, filters, sampling circuits, amplitude detectors, mixers, etc. Analog signals Sin waves, triangular, Range, bandwidth, precision, noise, speed of variation etc. ©Alex Doboli 2006

Functionality Control dominated systems Data dominated systems Multi tasking systems Multi-mode systems ©Alex Doboli 2006

Types of functionality ©Alex Doboli 2006

Types of functionality Continuous time systems Discrete-time systems Event-driven systems ©Alex Doboli 2006

Design requirements Low cost Short time to market Small size & weight Real-time constraints, latency, throughput Low power & low energy consumption Safety Data accuracy Robustness Flexibility in developing new applications ©Alex Doboli 2006

Timing (real-time) constraints ©Alex Doboli 2006

Analog Circuit Nonidealities ©Alex Doboli 2006

System performance & requirements Global constraints Local constraints Constraint transformation Tightly coupled systems Loosely coupled systems ©Alex Doboli 2006