Microprocessor PCB Design by Tuan Hung Huynh April

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

Outline l Background l Design Process l Application l Results

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

Background

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

Microcontroller l Microcontroller or Microprocessor? – Microcontroller – basic – Microprocessor - complex l Atmel and Intel 8051 core architecture – AT 89 S 8252 (8052) – AT 89 S 8253 (8053)

Design Process

Structure l l l l 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

l Schematic Layout Protel

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

Protel l PCB Layout – Physical representation

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

Protel l Assembly Files – Gerber Files – NC Drill Files . GTL Top Layer. GBL Bottom Layer. GTO Top Overlay. GBO Bottom Overlay. GTS Top Soldermask . GBS Bottom Soldermask. GKO Keep-out Layer. apr. drl Drill Files

Assembly Files l Top Silkscreen

Assembly Files l Top and Bottom Copper

Assembly Files l Top Soldermask and Bottom Soldermask

Assembly Files l Drill File

Creation of the PCB l Board Manufacture – Advanced Circuits www. 4 PCB. com l www. Free. DFM. com l l Component Vendors – Digikey – All Electronics

Application

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

Microprocessor Projects l Digital Metronome l T-Bird Taillights l Digital Clock – Port 3 SEC MIN

Microprocessor Projects l Serial Communications – Hyper-terminal – RS 232 buffer chip – Serial cable

Microprocessor Projects l Serial Communications Cable – DB 9 to RJ 45

Microprocessor Projects l Memory Mapped Input/Output – Data latch

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

Microprocessor Projects l Keypad – Data latch – PLD

Microprocessor Projects l Liquid Crystal Display – Data latch – PLD

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

In-System-Programming l Modification of the board is possible – Buffer chip – Programmable logic device – Re-wire Pin 20 Pin 8 RJ 45 Jack Programmable Logic Device Pin 8 Pin 19

In-System-Programming l ISP Cable – DB 25 to RJ 45

Results

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

Future Design l Reduction of Components l Dual Microcontrollers l USB l Surface Mount Components

Questions

References l l l Marcus O. Durham, Ph. D. Systems Design and the 8051. Second Edition. Techno. Press. Tulsa, OK. 2003 – 2004. Altium – Protel http: //www. 4 pcb. com http: //www. allelectronics. com http: //www. play-hookey. com/digital/experiments /seven_seg_led. html