1. ECE 2110: Introduction to Digital Systems Introduction (Contd.)

2. 2 Previous class Summary Digital devices Digital vs. analog Why digital

3. ECE 2110: Introduction to Digital systems Digital Devices Gates:  AND, OR, NOT (inverter): most important gates. Can realize any digital function.  NAND, NOR  XOR, XNOR Flip-flops (FF):  Stores 0/1, built from gates Gates: Combinational circuit: output depends ONLY on the current input combination. Flip-flops: Sequential circuit: output depends on current input As Well As past sequence of inputs. Hence, it has memory of past events.

4. 4 Digital Logic Binary system -- 0 & 1, LOW & HIGH, negated and asserted. Basic building blocks -- AND, OR, NOT

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6. 6 Electronic aspect of digital design Digital abstraction Range Noise margin Invalid range Specifications

7. 7 Software aspect of digital design Digital design need not involve any software tools. But: modern design, software tools are essential. Examples:  Schematic entry, HDLs (platform compilers, simulators, synthesis tools), simulators, test benches, timing analyzers and verifiers, word processors, high-level languages, CAD

8. 8 Integrated Circuits (IC) (Chapter 1.6--1.12) A collection of one or more gates fabricated on a single silicon chip.  Wafer, die Small-scale integration (SSI): 1-20 gates  DIP: dual in-line-pin package  Pin diagram, pinout MSI: 20-200 gates LSI: 200-1,000,000 VLSI: Fuzzy! Transistor count reached 50million in 1999 and 100 million in 2005.

9. 9 DIP pinout

10. 10 Printed-Circuit Board PCB or PWB (printed-wiring board) Mount ICs so that an IC can connect to other ICs in a system. SMT: Surface-mount technology MCM: multi-chip modules: high speed and density.

11. 11 Summary Electronics aspects of digital design Integrated Circuits SSI, MSI, LSI, VLSI Printed Circuit Boards

12. 12 Next… HW#1: a) Work problems 1.[3,6] b) Discuss three advantages of digital systems over analog ones. Finish reading Chapter 1,  If you use web search such as: www.acronymfinder.com for homework #1, make sure that definitions you chose are consistent with the text you read. Start Reading: Wakerly chapter 2: Number systems