ECE 3110: Introduction to Digital Systems

Introduction (Contd.)

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Previous class Summary

Digital devicesDigital vs. analogWhy digital

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Digital Logic

Binary system -- 0 & 1, LOW & HIGH, negated and asserted.

Basic building blocks -- AND, OR, NOT

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Electronic aspect of digital design

Digital abstraction

Range

Noise margin

Invalid range

Specifications

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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

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Integrated Circuits (IC)

A collection of one or more gates fabricated on a single silicon chip. Wafer, die

Small-scale integration (SSI): 1-20 DIP: dual in-line-pin package Pin diagram, pinout

MSI: 20-200 gates LSI: 200-200,000

VLSI: >100,000, 50million (1999)

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DIP

pinout

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Programmable Logic Device (PLD)

ICs which Logic function can be programmed after manufacturing.

2-level AND-OR gates using user-programmable connections PLAs: programmable Logic Arrarys. PALs: programmable array logic devices Programmable logic devices (PLDs)

CPLD: complex PLD FPGA: Field-Programmable Gate Array

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CPLD vs FPGA

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Application-Specific ICs (ASIC)

Semi-custom IC: chips designed for a particular, limited product/application

Reducing chip count, size, power consumption Higher performance. NRE: nonrecurring engineering cost

Standard cells: library Gate array: an IC with internal structure as an array of

gates, unspecified interconnection

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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 technologyMCM: multi-chip modules: high speed and

density.

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Summary

Electronics aspects of digital designIntegrated Circuits (wafer, die, SSI, MSI, LSI, VLSI)PLDs: PLAs, PALs, CPLD, FPGAASIC

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Next…

Number systems

Reading: Wakerly chapter 2