EECE 320 Lecture 1, Fall 2011

EECE 320 L1: Introduction 7 Chehab, AUB, 2003 Chapter1: Introduction  One of book goals:  Learn enough about basic principles to understand what happens when you use software tools  A digital designer must be competent in:  Debugging good troubleshooter - Planning - Systematic approach - Patience - Logic (work by elimination)  Business requirements and practices - Documentation standards - Component availability - Target specifications - Scheduling  Good communications skills Transmit and Receive EECE 320 L1: Introduction 8 Chehab, AUB, 2003 Analog versus Digital  Two basic ways of representing information:  Analog: Take values across a continuous range (voltage, current)  Digital: Take only values from a discrete set - Decimal: {0,1,…,9}, Binary: {0,1} or {T,F} or {Low, High}  Analog-to-Digital and Digital-to-Analog Converters Time 0 1 Time Amplitude Analog signal: Values  Reals Digital signal: Values  {0,1} Amplitude EECE 320 L1: Introduction 9 Chehab, AUB, 2003 Digital Revolution  Digital Revolution  Cameras: A picture is stored as an array of pixels. A pixel stores the intensities of RGB components as 8 bits each. (JPEG compression digital storage and processing)  Video Recording: Digital Versatile Disk, DVD, (MPEG2)  Audio Recording: Digital Compact Disk, CD  Telephone system: Digital transmission between central offices, cellular systems  Traffic lights: from electromechanical timers to controllers to maximize vehicle throughput  Movie effects: computer synthesis instead of tricks & miniatures EECE 320 L1: Introduction 10 Chehab, AUB, 2003 Reasons for Digital Revolution 1. Reproducibility of results  Digital circuit: same inputs  same outputs  Analog circuit: the output depends on temperature, power- supply voltage, component aging, … 2. Ease of design  No need for special math skills, just logic 3. Flexibility and functionality 4. Programmability  Hardware descriptive languages, HDLs 5. Speed • A transistor can switch in less than 10 ps • A circuit can produce an output in 1 ns  1 Billion results/s EECE 320 L1: Introduction 11 Chehab, AUB, 2003 Reasons for Digital Revolution  Economy  Commonly used circuits can be integrated into chips and mass- produced at low cost and used in different products such as calculators, digital watches, …  Steadily advancing technology  Digital designers try to accommodate advances in technology while designing. An example is expansion memory slots in a computer EECE 320 L1: Introduction 12 Chehab, AUB, 2003 Design Tradeoffs for Digital Systems  Digital Computer  Typically designed to maximize performance: “Optimized for speed”  Pocket Calculator  Typically designed to minimize cost: “Optimized for cost”  Tradeoff with speed  Portable Computer  Designed to minimize power: “Optimized for power”  Low power comes at the expense of lower speed and higher cost (e.g. desktop vs. notebook) Central Processing Unit Memory System (storage) Instructions, data data input output clock addresses EECE 320 L1: Introduction 13 Chehab, AUB, 2003 Next Lecture and Reminders  Next lecture  Number Systems and Codes  Reminders