Microprocessor PCB Design by: Tuan Hung Huynh April 3, 2006

Outline Background Design Process Application Results

Purpose Designing computer circuits and software for the Microprocessor class. PCB layout software Documentation

Background

Past Designs People to mention – Wi Sugiri (projects) – Dan Sossaman (board) – Neil Clukode – Matt Olson – Tuan Huynh – Chris Carpenter

Microcontroller Microcontroller or Microprocessor? – Microcontroller – basic – Microprocessor - complex Atmel and Intel 8051 core architecture – AT89S8252 (8052) – AT89S8253 (8053)

Design Process

Structure Developing the schematic layout Updating and improvements Ordering of components Developing software Transforming into a workable circuit Testing and demonstration Optional manufacture of the PCB

Protel Schematic Layout

Protel Schematic and PCB Libraries Custom components Link of files Schematic library PCB library

Protel PCB Layout – Physical representation

Protel Design Rule Check (DRC) – Short Circuits – Broken Nets – Height and Width Constraints – Hole Size – Clearance Constraints

Protel Assembly Files – Gerber Files – NC Drill Files.GTLTop Layer.GBLBottom Layer.GTOTop Overlay.GBOBottom Overlay.GTSTop Soldermask.GBSBottom Soldermask.GKOKeep-out Layer.apr Drill Files.drr.drl

Assembly Files Top Silkscreen

Assembly Files Top and Bottom Copper

Assembly Files Top Soldermask and Bottom Soldermask

Assembly Files Drill File

Creation of the PCB Board Manufacture – Advanced Circuits Component Vendors – Digikey – All Electronics

Application

Microprocessor Projects Microprocessor Design class:  Digital Metronome  T-Bird Taillights  Digital Clock  Serial Communication  Memory Mapped Input/Output  7-Segment Displays  Keypad Input  LCD Display

Microprocessor Projects Digital Metronome T-Bird Taillights Digital Clock – Port 3 SECMIN

Microprocessor Projects Serial Communications – Hyper-terminal – RS232 buffer chip – Serial cable

Microprocessor Projects Serial Communications Cable – DB9 to RJ45

Microprocessor Projects Memory Mapped Input/Output – Data latch

Microprocessor Projects 7-Segement Displays – Data latch – Programmable logic device – FETs

Microprocessor Projects Keypad – Data latch – PLD

Microprocessor Projects Liquid Crystal Display – Data latch – PLD

Problems Encountered Issues with new microcontrollers – Chip burners – Capacitance – Internal Fuse Bits In-System-Programming Circuit

In-System-Programming Modification of the board is possible – Buffer chip – Programmable logic device – Re-wire Programmable Logic Device Pin 8 Pin 20 RJ45 Jack Pin 8 Pin 19

In-System-Programming ISP Cable – DB25 to RJ45

Results

Completion Board applied in the classroom Update from previous designs Capable of future updates

Future Design Reduction of Components Dual Microcontrollers USB Surface Mount Components

Questions

References Marcus O. Durham, PhD. Systems Design and the Second Edition. TechnoPress. Tulsa, OK – Altium – Protel /seven_seg_led.html