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ElectronicsUnit PADS Logic (9.3)

Training Manual

Fifth Edition


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PADS Logic

Training Manual

Fifth Edition

Notice to all readers

This training manual is developed for educational purposes with no commercial value and is solely

used in the Industrial centre, The Hong Kong Polytechnic University.

Copyright 2011 by

Industrial Centre, The Hong Kong Polytechnic University

All rights reserved. No parts of this work may be reproduced or stored in a retrieval

system, or transmitted, in any form or by any means, electronic, mechanical,photocopying, recording, or otherwise, without the prior written permission of

the editors.

Editors:

First Edition : W H Kong, Jasper Wong (Feb/2000)

Second Edition : W H MA, Jasper Wong (Oct/2003)Third Edition : Kelvin Leung, Jasper Wong (Nov/2005)

Fourth Edition : W H MA, Jasper Wong (Oct/2009)

Fifth Edition : W H MA, Jasper Wong (Oct/2011)

Acknowledgments

The editors would like to acknowledge all staff from the Electronics Unit

of the Industrial Centre, The Hong Kong Polytechnic University for their

efforts and contribution to this training manual.


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Table of Contents

Training Objectives & PADS Logic Flow 1

1 PADS Logic Basics 21.1 Introduction 2

1.2 Getting Started 2

1.3 Using the Workspace 3

1.4 Functional Area of the Worksheet 31.41 Toolbars and Toolboxes 3

1.42 Object Selector Toolbar 4

1.43 Status Bar 4

1.5 Keyboard Command Shortcuts 5

1.51 Modeless Command 5

1.52 Shortcut Keys Commands 71.6 Design Setup 8

1.61 Global Tab 10

1.62 Design Tab 111.63 Text Tab 12

Exercise 1 : Setting Grids, Zoom ,Smooth Scrolling 131.7 Colors Setup 16

2 Starting a New Design 18

2.1

2.2

Setup Design Sheet

Setup Library

18

19

2.3 Adding Parts 20Exercise 2 : Adding Parts , Capture View 20

2.4 Copying and Deleting Parts 22

Exercise 3 : Copying and Deleting Parts 22

2.5 Adding and Editing Connections 24

Exercise 4 : Adding Connections 24

Exercise 5 : Modifying and Delete Connections 262.6 Add a Power Connection and Off Page 27

Exercise 6 : Add a Power Connection 27

Exercise 7 : Add an Off Page 30

2.7 Adding Busses 31

Exercise 8 : Creating and Connecting a Bus 31

2.8 Changing Schematic Data 34

Exercise 9 : Query , Rename Net and Part 34

Exercise 10 : Change Part Information 37

Exercise 11 : Grouping 40

2.9 Generating Reports 43

Exercise 12 : Creating a Netlist , Export to PADS Layout and BOM 43

3 PADS Logic Library 46

3.1 Creating a New Library 48

Exercise 13 : Creating a New library 48

3.2 Creating a CAE Decal 50

Exercise 14 : Creating a CAE Decal 50

3.3 Creating a New Part Type 55

Exercise 15 : Creating a New Part Type 55

3.4 Test The New Part Type 62

Exercise 16 : Link to PADS Layout 62


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3.5 Library Practical Task 1 65

Exercise 18 : Creating a Microcontroller 65


Exercise 19 : Creating a Transistor 67


Exercise 20 : Creating a Relay 73

4 Hierarchical Design 74

Exercise 21 : create a Hierarchical Symbol 74

5 Printing and Plotting 77

Exercise 22 : Printing and Plotting 77

6 Integrated Exercise 1 79

7 Integrated Exercise 2 80

8 Drawing Exercise 82

8.1 8051 Control Part 82

8.2 ISD Voice Recorder 838.3 Keypads 84

8.4 Decision Maker 85

8.5 Digital Recorder 86

8.6 Meter Detector 87

8.7 Motor Control 1 88

8.8 Music Box 898.9 Power Supply 90

8.10 Pre Amplifier 91

8.11 Temperature Control 92

8.12 Touch Switch 93

8.13 Voice Activation Switch 94

8.14 PWM Amplifier 95

8.15 Home Appliance ControlBlock Diagram (Hierarchical) 968.16 Home Appliance ControlCPU (Hierarchical) 97

8.17 Home Appliance ControlPower Supply (Hierarchical) 98

8.18 Home Appliance ControlControl Unit (Hierarchical) 99

8.19 Home Appliance ControlAD Converter (Hierarchical) 100


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Electronics Unit, Industrial Centre, The Hong Kong Polytechnic University

PADS Logic 9.3 Training Manual 1

Objectives

To recognize the background knowledge for schematic designed.

Hands on the basic electronic drawing techniques.

Prepare the design for PCB Layout.

PADS Logic Flow

This training handout provides a brief description for student to draw schematics of your system.

1. Set up a new design

2. Set up rules and constraints

3. Place parts

4. Wire the schematic

5. Prepare the design for PCB Layout

Training Objectives &

PADS Logic Flow


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1 PADS Logic Basics

1.1 Introduction

PADS Logic is a robust, multi-sheet, schematic capture solution designed to build an effective,yet simplified, front-end environment for PowerPCB. PADS Logic offers instant access to every

sheet in your design, on-line parts editing and library management facilities, and rapid

navigational aids. Fully integrated with PowerPCB for efficient design transfer between schematicand layout, PADS Logic allows you to quickly identify corresponding components ensuring

placement and accuracy.

1.2 Getting Started

Double-click the PADS Logic icon and enter to the following worksheet.

Or

Start PADS Logic by choosing

Start / Programs / MentorGraphics SDD / PADS 9.x / Design Entry / PADS Logic


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1.3 Using the Workspace

A small information window called the Status Window appears on the left side of the screen when

you start PADS Logic and Press Ctrl + Alt + S.Close this window for now by choosing theWindow Close icon on the Status Window.

The workspace in PADS Logic measures 56 inches by56 inches. The origin of the, or 0,0 coordinate location,

is represented by a large white datum. When you start

PADS Logic or open a new file, the origin is located at

the lower-left corner of the sheet, at a medium magnification. Thelarge white rectangle represents the area of the schematic sheet. For a

B Size schematic the area is 11 x 17. For a C size sheet it is 17 x 22,

and so on.

1.4 Functional Area of the Worksheet

1.41 Toolbars and Toolboxes

PADS Logic uses Windows-standard toolbars and toolboxes (collections of icons that graphicallyrepresent available commands). The toolbar is located below the menu bar. You can open

toolboxes for specific command sets by choosing the corresponding icon on the standard toolbar

or by choosing commands from the Window menu. You will use both methods in this tutorial.

Note: Only one toolbox can be open at a time.

ThePADS Logic toolbarcontains icons that represent the commands available in

PADS Logic. The following command icons are available on the toolbar:

Open File Opens the File Open dialog box. This is the same as the

File/Open command.

Save File Opens the File Save As dialog box. This is the same as

the File/Save command.

Sheet Select Displays the current active sheet. Use to change the

current active sheet.

Select Mode Places PADS Logic in Select mode.

Move Mode Places PADS Logic in Move mode.

Duplicate Mode Places PADS Logic in Duplicate mode.

Delete Mode Places PADS Logic in Delete mode.

Properties Mode Places PADS Logic in Properties mode.

Add Part Add a Part to Worksheet


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Add Connection Add Connections to Parts and ConnectorsAdd Bus Buses are used to consolidate a group of nets into one

connection.

Undo Reverses the last command or the last action taken.

Redo Reverses the last Undo action.

Zoom Toggles Zoom mode on or off.

Sheet Border Adjusts the display to fit the board outline.

Redraw Repaints the screen without modifying the current zoom

factor or coordinate position.

You can open or close a toolbar by choosing it from the Windows/Toolbars menu.

You can undock a toolbar and place it anywhere on screen. It is called a floating

toolbar because it is not attached to the sides of the application window. To floatthe toolbar, click and hold the left mouse button on the toolbar background. Drag

the toolbar to a new location and release the button. This is called drag and drop.

All PADS Logic toolboxes can be manipulated the same way.

1.42 Object Selector Toolbar

The Object Selector toolbar is visible, by default, at the bottom of the PADS Logic main window

and is available only in Schematic Editor mode.

The object selector toolbar allows us to select any objects on the schematic in parts, gates, nets or

groups.

1.43 Status Bar

Displays information on a selected connection, route, or component.

Line WidthDisplays the default line width setting.

Design Grid :Displays the design grid setting.

X,Y Coordinates:Displays the horizontal distance of the cursor from 0,0 as the X coordinate.

Displays the vertical distance of the cursor from 0,0 as the Y coordinate.


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1.5 Keyboard Command Shortcuts

PADS Logic has a number of keyboard shortcuts that start commonly used commands or set

preferences. You will use some of the shortcuts throughout the tutorial. There are two types of

keyboard shortcuts in PADS Logic:

Modeless Commands

Commands invoked through the keyboard. The available commands handle display options,

design settings, and mouse click substitutions.

Shortcut Keys Commands

Change settings or execute commands without using the mouse. Windows shortcut keys, such as

Alt-F to open the File menu, are also used.

Mouse Cli ck Substitu tes

M Activates pop-up for current mode (right mouse button).Spacebar Activates a left mouse buttonclick (to add corners, select

items, complete etc.) in the current cursor location.

Canceling Commands and Actions

You can cancel the current command or sequence at any time by pressing the

Esc key or by clicking the right mouse button and choosing Cancel from the

pop-up menu.

1.51 Modeless Command:

You can set or change some settings and functions at any time using a code letter for the

command, entering the new value, and pressing Enter. This is called aModeless Command.

Modeless Commands usually apply to values that you change frequently during design. Use the

Modeless Command G, for example to change the grid setting. Type G, the new setting, and

press Enter. Below is a summary of the Modeless Commands in PADS Logic:

To show this help topic at any time while PADS Logic is running, type? and press Enter.

Note: (X, Y) = coordinates; (s) = text; (n) = number.

Grid Settings

Command Description

G Sets the design grid, for example G50.

GD Dot grid setting, for example GD100.


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Design and Hierarchy

Command Description

HI Invokes Hierarchical Push.

HO Invokes Hierarchical Pop.

Q Invokes Quick Measure.

R Set minimum (Real) display width for paths.

SH Select sheet name or number.

W Set current line width.

Searching

Command Description

S Search for named item (pin, part or net), for example SU1.

S Search absolute at , for example S1000 1000.

SR Search relative X and Y, for example SR-200 100.

SRX Search relative X, for example SRX300.

SRY Search relative Y, for example SRY400.

SX Absolute move to , current Y, for example SX300.

SY Absolute move to current X, for example SY400.

Angles

Examples:

G100 Set the design grid to 100 mils

GD100 Set the display grid to 100 mils.

SH2 Select sheet 2.

W20 Set current line width to 20 mils.

SR1 Search R1(Resistor 1).

Command Description

AA Any angle.

AD Diagonal angle.

AO Orthogonal angle.


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1.52 Shortcut Keys Commands:

For mouse-less operation, use keyboard shortcuts to start commands for selected items and

change some system settings. Following are the shortcut assignments for PADS Logic.

PADS Logic Control Key Shortcuts

Shortcut Description Shortcut Description

Ctrl+A Select All on Sheet Ctrl+Z Undo

Ctrl+B View sheet Ctrl+Alt+C Display Colors Setup

Ctrl+C Copy Ctrl+Alt+E View Extents

Ctrl+D Redraw Ctrl+Alt+F Filter

Ctrl+E Move selected object(s) Ctrl+Alt+G Preferences

Ctrl+F Flip selected on X axis Ctrl+Alt+M Toggle menu bar

Ctrl+J

Horizontally justify text

during move Ctrl+Shift+J Vertically justify text during moveCtrl+N New file Ctrl+Alt+P View Previous

Ctrl+O Open file Ctrl+Alt+S Status Window

Ctrl+P Print/Plot Ctrl+Enter Options

Ctrl+Q Query/Modify Ctrl+Tab Cycle Alternate Gate Decals

Ctrl+R Rotate selected Ctrl+PageDown

Reset delta coordinates to measure from

current position

Ctrl+S Save Shift+Ctrl+A Select All on Schematic

Ctrl+V Paste Shift+Ctrl+D Draw Group while in Move Group Mode

Ctrl+W View Zoom mode Shift+Ctrl+F Flip selected on Y axis

Ctrl+X Cut Shift+Ctrl+P Record prompt windows toggle (macros)

Ctrl+Y Redo Ctrl+ Duplicate

PADS Logic Function Key Shortcuts


F1 Help F9

Absolute/Relative coordinates toggle

(macros)

F2 Add Connection F10 End recording (macros)

F8

Mouse move

compression (macros)

Other PADS Logic Key Shortcuts


BackSpace Remove last connection corner Alt+Enter Properties

Esc Cancel command Spacebar Left mouse click

Home Sheet Alt+Spacebar

Add Offpage while in Add

Connection mode

Del Delete Shift+Spacebar

Add Power Symbol while in Add

Connection mode


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1.6 Design Setup

Before we create schematics, we have to define the system operating environment such as

the size of worksheet, grid size, display color, etc.

1.61 General Tab

The Global tab sets interface parameters and attributes that are global to the design

process regardless of the current editing mode.

Cursor Style

Displays the cursor as an arrow (normal), small cross, large cross, or full screen

crosshair. Choose a cursor style from the drop-down list box.

Diagonal Cursor

Displays the cursor diagonally.

Keep View on Window Resize

Maintains the proportional scale and the same area of the screen in the windowwhen you resize the view.

Tools / Options / General


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Display Dot Grid

Defines the spacing for the dot grid display in the work area. This grid is a

visible guide for drawing lines, decals, connections, etc. It is independent of the

system grid on the Status Bar.

To change the display grid, enter the new value in units of 2 mil increments. Ifthe grid is not visible when the work area redraws, you probably set an interval

that is too small to display at all zoom levels. Zoom in several times to display

the grid. A reasonable value for the display grid is 500 or 1000.

Display OLE Objects

When it is selected, linked and embedded objects are displayed in the work area.

Update on Redraw

Updates the PADS Logic linked or embedded object in the container applicationwhen the following is true:

You are editing the PADS Logic object in a separate window.

You choose the Redraw icon in the separate window.

To increase performance, turn this option off. This option only effects PADS Logic

when it is embedded in another application.

Draw Background

Draws the PADS Logic background color in the linked or embedded PADS Logic

object. You set this color in the Display Colors Setup dialog box. When this

option is off, the background of the PADS Logic object is transparent: you can seethe through the object to the container application's background.

This option only affects PADS Logic when it is embedded in another application.

Backup Interval

Define time interval (in minutes) between two automatic backups. Type a valuebetween 1and 30 minutes.

Number Backups

Set the number (1-9) of backup files to be created. Backup files are named

as #.sch, where # is a sequential number. E.g. logic0.sch, logic1.schand etc.

Backups File

Opens the Backup File dialog box where you can choose a location and filename for thebackup file. The default backup filename is Logic0.schwhich PADS Logic saves to the

C:\PADS Projectsfolder.


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1.62 Design Tab

The Design tab defines the parameters for schematic editing.

Design Grid Size

Sets the snap grid size. The snap grid is the minimum distance for cursor movement.

Type a value between 2 and 1000 that is a multiple of 2, for example, 2, 4, 50, or 100.

Sheet Size

Sets the sheet size. When you change the sheet size, it affects all sheets of the schematic.Choose a size from either US standard sheet sizes A through F or international standard

drawing sizes A4 through A0.

Sheet Numbers Separators

Sets the open and close characters that enclose sheet numbers. Type characters such as

quotes " " and curly { } or straight [ ] brackets.

Show Off-Page Sheet Numbers

Displays sheet reference numbers adjacent to off-page reference symbols and bus names.

Tools / Options / Design


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Numbers per Line

Sets how many sheet numbers display per line when Show Off-Page Sheet Numbers is

on. The sheet numbers display on a line below the net name. Type a value between 0 and99. Depending on the value you specify, you can stack or line up the sheet number

references.

Tie Dot Diameter

Sets the diameter of tie dots. Type a value between 0 and 100.

Bus Angle Offset

Defines the starting point distance from the bus for the bus tap. The bus tap joins

connections to the bus. Type a value between 0 and 250.

Preserve Reference Designators on Paste

Uses a group's current reference designator assignments when possible.Turn this option off to assign reference designators in the pasted group the first

or next available number

1.63 Text Tab

The text tab specifies the font and/or size of text characters and lines. When you change text

or line size, PADS Logic modifies all entries/objects in the schematic with the new values.

Changes you make to symbol text and decal line sizes only modify the values for the

current schematic, not the part type in the library. To change the part type in the library, you

must modify it using the Part Editor.

Tools / Options / Text


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Lines Widths Tab

Sets the line width for connections, busses, and the lines within logic symbols

and 2D items. Type a value between 1 and 250 for connections and busses. You

can set multiple widths for decals and 2D items. Type a value between 1 and 250

for decals and 2D items.


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Exercise 1 : Setting Grids , Zoom , Smooth Scrolling

PADS Logic has two kinds of grids, the design grid and the display grid.

Design GridThe Design Grid determines the minimum snap distance for the cursor while editing.

Display GridThis dot-type grid is a visual aid. You can set the Display Grid to match your design grid,

or you can set it at larger or smaller multiples of the design grid. Choose Tools/Options

and choose the General tab to view the current display grid setting. To disable the

Display Grid, set Display Dot Grid to a small value, such as 10. It is not really disabled,

but you will not see it unless you zoom in significantly.

Gri d Exercise:

The spacing for each grid is individually set using Setup/Preferences or usingmodeless commands. In the following exercise, youll use modeless commands to

set the design and display grids.

To make it easier to view changes in grid, first open a file.

1. Choose File/Open/PADS Projects/samplesor choose the Open icon from the toolbar.

2. In the File Open dialog box, choose the file named Previewstart.schand choose

Open to load it into PADS Logic.

3. If the Preferences dialog box is open, choose OK to close this dialog box.

4. In the Modeless Command dialog box, Type gd, for Display Grid.

5. Type 500and press Enter to complete the modeless command entry.

Note: You may have to zoom in or out to see the dot grid; Depends on the grid value

entered, the dot grid can be viewed by zooming in different level.

You can set thedesign gridby typing g500and pressing Enter. Note that a space is not

needed between the modeless command and the value.


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Zoom Exercise:

To zoom, use the following steps.

1. Choose the ( Zoom icon ) on the toolbar.

2. Zoom in.

a. Click and hold the mouse button in the center of the area you want to magnify.

b. Drag the cursor upward, moving the mouse away from you. A dynamic

rectangle attaches to and moves with the cursor.

c. When the rectangle encompasses the area you want to magnify, release the

mouse button to complete the operation.

3. Zoom out.

Repeat Step a, but drag the cursor downward. A solid rectangle, representingthe current workspace view, appears along with a dynamic rectangle

representing the new view of the workspace.

4. Practice using Zoom mode to adjust the magnification. To reestablish the original

view, choose ( Sheet Home icon )

5. Click or choose the Zoom mode icon to end Zoom mode.


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Using the Numeric Keypad

You can control the view using the extended keypad or the numeric keypad, located on

the far right of the keyboards. The NumLock light can be on or off except wherespecified.

Click To

Home Fits board to the view.

End Redraws current view.

Arrows With Num Lock On, pans the viewing window. Moves one-

half the screen width in the direction of the arrow. With Num

Lock Off, moves cursor on grid unit.

5 With Num Lock On, draws zoom rectangle.

PgUp Zooms In centered at cursor location.

PgDn Zooms Out centered at cursor location.

Ins Centers the view at current cursor location, without zooming.

Saving and Restoring Views

You can save a work area view for easy restoration.

1. Arrange the work area to the view that you want to capture.

2. Choose View/Save viewfrom the menu. The Save viewdialog box appears.3. In the Save viewdialog box choose Capture.

4. Type a name " View1 "in the Capture a new view text box and choose OK.

You can create up to nine views. The view names appear at the bottom of the

View menu.

To restore the view to one previously captured, select its

name from the View Name list box and choose Apply.

When you change the view, PADS Logic automatically

saves the previous view. Choose Previous View in the

View Name list box and choose Apply to restore this view.

Note: Capture is not available while in the Part Editor.


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1.7 Colors Setup

To open the Setup Colors dialog box, choose Setup/Display Colors. PADS Logic saves the setup

for the schematic with the schematic. The color selection for display does not affect plotting of theschematic.

Selected Color Area

Sets a color to assign to items. To change the available colors, choose Palette.

Miscellaneous Area

Applies colors, including foreground and background, to the following items:

Background (work area surface) Selections

Connections

Busses

Lines

Parts

Hierarchical components

To make an item invisible, set it to the Background color. Do not set theForeground color and Background color to the same color.

Setup / Display Colors


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Titles Area

Applies colors to the following text items:

Text

Reference Designators Part Types

Part Text

Pin Numbers

Net Names

Fields

Two color box columns appear next to the text item list. Box indicates the color of

the box drawn around the text. This box indicates the exact size of the text item

when it is plotted, thereby helping you avoid overlaps while moving the item,

and it provides visibility of the text item at small zoom levels.

Configuration Area

Saves color assignments to a file. When you finish setting color assignments, choose

Save from the Configuration area. Type the configuration name in the Save

Configuration dialog box. PADS Logic saves configuration files in theC:\MentorGraphics\9.3PADS\SDD_HOME\Settings with a .ccfextension.

The configuration names also appear at the bottom of the Setup menu.

To modify an existing configuration with the current color settings, choose Save.

The current configuration filename appears in the Save Configurations dialog

box. You can overwrite the settings in this file or specify a different .ccf file, and

choose OK.

Palette

Opens the Color dialog box where you can specify new colors or customize colors that

appear in the Selected Color area.

Default Palette

Restores the default color settings in the Selected Color area. To change the default

palette, complete the modifications to the Selected Color area and choose Save.

Type default in the Save Configurations dialog box to override the existing default

configuration and choose OK.


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2 Starting a New Design

To add new design information, open one of the toolboxes in the toolbar:

Add and edit parts from libraries, create and modify hierarchical symbols, add connections,and swap pins and reference designators.

Use the Bus toolbox to define bus structures.

Create and edit non-electrical information, including text, charts, notes, etc.

2.1 Setup Design Sheet

Use the Sheets dialog box to edit the sheet set of the current schematic in the work area. Choose the

Setup/Sheetscommand to open this dialog box. Using Sheets allows you to add and delete sheets

from the set and to modify sheet names and the numeric order of the set. You can create up to 1024sheets.

Double-click on a sheet name to view it in the work area. Choose a sheet in the list box, pause, and

then choose it again to rename the sheet. Spaces are not valid characters in a sheet name. You can

also use the View and Rename buttons for these functions.

Setting the Sheet Size

You can change the size of the sheet by choosing Tools/Options. Choose the Design tab and

locate the Sheet Size drop-down list box and Sheet border leave the current sheet size and

border as A3or A4


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2.2 Setup Library

Choose File/Libraryto open the Library Manager. Use the library Manager to perform

operations associated with editing and copying the contents of libraries,

When you add a part to the design, you are actually retrieving information about that part from the

library. The Manage Lib Listdialog box contains a list of libraries to search.

Choosing Manage Lib list, select the library and press Add bottomto add the

training library ( enc_traini ng.pt9 ,MUSIC.PT9 , SMTMUSIC.PT9 ) from C:\PADS Projectsor

other location .


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2.3 Adding Parts

Typically, schematic entry requires many add, copy, or delete part operations .These

operations are performed easily in PADS Logic using the Add, Copy, and Delete commands.

Exercise 2 : Adding Parts , Capture View

Adding Parts :

1. Choose File / Open / Samples Previewstart.sch.

2. Key in modeless command S 7000 8000and Press PgUP(number 9) to zoom in, Resize your view tofit an area around U1 and the B gate of U5, as shown below.

3. Choose ( Schematic Editing Toolbar icon) ( Add part ) type AM100* andApply Select AM100415 from the list of parts. Add .

( In the Add Part dialog box, type AM100*. This tells PADS Logic to conduct a "wild card" search of

the library for all parts containing the first five characters, AM100, and display them in the Parts listbox. )

4. Key in modeless command S 6500 7900 and Enter

5. Click (or Press Space bar ) to place the part on the schematic


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6. Press ESCto complete the operation.

( When you finish experimenting, press the Esc key or choose Cancel from the pop-up menu to exitthe Add Part mode. )

7. Choose ( Properties) Select U3(AM100415) Click Visibility from Modify fieldSelect Pin Name Display pin name .


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2.4 Copying and Deleting Parts

Typically, schematic entry requires many add, copy, or delete part operations.

These operations are performed easily in PADS Logic using the Add, Copy, and

Delete commands.

Exercise 3: Copying, and Deleting Parts

Copy Parts :

1. Choose File / Open /Samples Previewpart.sch

2. Place a Part CAP-CK05to location X: 9000, Y: 4000.(Use method of exercise 2 and PADS Logic determined that designator number C10was unused. So

automatically assigns reference designator number used for prefix C was 10.)

3. Select C10, Right click and select Duplicate (a new copy of the part attaches to the cursor )

4. Right click the mouse bottom and select Step and Repeat


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Set direction : right , Count : 3 , distance :500 and Press Preview .

5. Press OKto copy the part .

6. Press ESCto Complete the operation.

Delete Parts :

To remove the multiple instances of Part CAP-CK05.

1. Choose ( Select icon )Select C10 to C13

2. You can see the status windows to display Multiple Selection.

3. Choose (Delete icon) to delete all selected parts.

4. Choose (Refresh icon) or the View/Redrawon the toolbar to refresh the workspace display.


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2.5 Adding and Editing Connections

Interconnect parts using the Add Connection command. Each new connection is

automatically assigned a system-generated netname.

Exercise 4: Adding Connections

Adding connection :

1. Choose File / Open / Samples Previewpart.sch

2. Key in modeless command g 300, Set design grid to 300 mil for test design grid function.

3. Key in modeless command gd 1000, Set display grid to 1000 mil for test display grid function.

4. Open Tools/Options/Design, Set Tie dot diameterto 10

5. Choose the ( Add Connection icon )

6. Select pin number 1on the right side of U3, and connect it to pin 6 of U5-B.

7. Move the cursor horizontally to the midpoint between U3 pin 1 and U5-B pin 6, and click to add a

new corner. Position the cursor over U3 pin 15 and try tocomplete the connection.

8. You wil l encounter some problems: ( a ) You cannot make connection of U3 pin 15 .

( b ) No meaning of display grid.

( c ) The Tie dot ( junction ) is too small .

Solution :

9. Key in modeless command g 100, Set design grid to 100 mil for test design grid function.

10. Key in modeless command gd 100, Set display grid to 100 mil for test display grid function.

11. Open Tools/Options/Design, Set Tie dot diameterto70.


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When you reconfigure the setup, you can

(a) Complete the connection, because The Design Grid determines the minimum snap distance forthe cursor while editing.

(b) The dot-type grid is a visual aid. Set the Display Grid to design grid to let the user easy to seethe dimension of the parts.

(c) Sets the diameter of tie dots large, it is easy for viewing and editing the schematic diagram.


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Exercise 5: Modify and Delete Connections

You can modify connections using either the Move or Delete commands.

Modify connection :

1. Choose the ( Move icon ) from the toolbar.

2. Click at the Corner of the connection segment attached to U3 pin 15.

3. Move the path to U5-B pin 5 and complete the connection.

4. You can change the connection from U5-B Pin 6 to U5-B Pin 5.

Delete connection :

You use the Delete command to remove the connection.

1. Choose the ( Delete icon ) from the toolbar.

2. Select the connection between U3 pin 1 and U5B pin 6.


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2.6 Add a Power Connection and Off Page

You can connect to power or ground using the same Add Connection operations, but you

terminate the connection with a special symbol. The symbol represents a connection to the

specified net.

Create power and ground symbols in the Part Editor. Each symbol has a primary symbol and mayoptionally have several alternate symbols. In addition, you can associate each power or ground

symbol (and its alternates) with a net and give each its own graphic symbol. This is useful when

the schematic has many power or many ground nets.

Exercise 6: Add a Power Connection

To complete the connections to U3, you must connect pin 15 of U3 to the +12V power net.

Add a Power connection :

1. Press Ctrl + Alt + S, Let Status Window appears on the screen

2. Choose File / Open / Samples Previewpart.sch.

3. Delete the connection of U3 pin 15 and 1.

4. Choose ( Add Connection icon ) .

5. Select U3 pin 15 ,move the cursor horizontally and click to add a new corner.

6. With the connection attached to the cursor, Right-Click the mouse bottom and choose Powerfrom thepop-up menu .A power symbol attaches to the cursor.


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7. Choose an Alternate Symbol :

With the special symbol attached to the cursor, choose Alternatefrom the pop-up menu, or press

Ctrl-Tabrepeatedly until the netname +12Vappears in the Status Bar. The pin connection alsoappears in the Status Bar.

Connect Resistors R5 and R2 to Ground and Power:

There are also two resistors on the schematic requiring power and ground connections.

8. Use the search modeless command sr5 to locate R5. Type sr5 and press Enter.

9. Select R5pin 2; a connection attaches to the cursor.

10. Choose Ground from the pop-up menu. A ground symbol attaches to the cursor. Position the symboljust below and to the right of R5 and click to complete the connection.

11. Locate R2by typing sr2 and pressing Enter.

12. Select R2pin 2and a connection attaches to the cursor.

13. Before you add the connection to power, you must enable thedisplay of the netname so the power symbol is visible when placed

on the schematic. Choose Display PG Name from the pop-up menu.

14. Choose Power from the pop-up menu to connect R2.2 to power.


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15. With the special symbol attached to the cursor, choose Alternate from the pop-up, or press Ctrl-Tabrepeatedly until the netname +5V appears in the Status Bar. Use the information that appears in the

Status Bar (or the netname graphics) to choose the +5V symbol.

16. Position the symbol directly above R2 and click to complete the connection.

Practical Exercise: Connect U1 and U3Using the operations defined above, connect U1 and U3 same as below graphic.


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Exercise 7: Add an Off-page

Off-page symbols are added to connections to make indirect connections between parts on the same sheet

or across multiple sheets. Off-page symbols are added in the same manner as power and ground symbols.

Add a Off -page connection :

1. Choose ( Add Connection icon ) .

2. Locate U7 by tying su7 and pressing Enter. Select pin 1.

3. Move the cursor horizontally and click to add a corner in the connection. Move the cursor up and tothe right just above the U7 reference designator.

4. Choose Offpage from the pop-up menu.

5. Choose X Mirror from the pop-up menu.

6. Click to place the off-page symbol. The Add Connection prompt appears.

7. Type the name 28MHZ in the text box, and choose OK


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2.7 Adding Busses

Busses are used in PADS Logic to quickly add connections for a collection of sequentially named nets,such as an address or data bus.

Exercise 8: Creating and Connecting a Bus

Creating a Bus :

Create bus using the Add Bus command in the Bus toolbox. In the following exercise you will add a busand connect U7 to the bus

1. Choose File / Open / Samples previewconnect.sch.

2. Search for U7 by typing su7 and pressing Enter. Resize your view as necessary, e.g. use Zoomfunction key .

3. Choose ( Add Bus icon )

4. Key in modeless command S 9400 4400.

5. Click to begin creating the bus and click again at X9400, Y6100 to add the first corner.

6. Position the cursor at X8100, Y6200 and double-click, or select Complete from the pop-up menuto complete the definition of the bus. The Add Bus prompt appears

7. Choose the Bit Format radio button in the Bus Typebox.

8. Type D[00:07] to name the bus and choose OK. The bus name label attaches to the cursor.

9. Position the label just above the bus and click to place it


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Connecting to a Bus :

10. Choose ( Schematic Editing Toolbar icon) ( Add Connection icon ) .Choose theAdd Connection icon from the Design toolbox.

11. Select U7pin 12, and position the cursor over the vertical segment of the bus.

12. Click to add a connection to the bus. The Add Bus Net Name prompt appears with the netname D00 inthe text box.

13. Choose OK to accept the D00 netname.

14. Choose the Move iconfrom the pop-up menu and position the netname label over the connection.Click to place it.

15. Repeat steps 11-13 to connect U7 pin 13 to D01.


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Using Copy to Step and Repeat Bus Connections:

16. You can use the Copy command to step and repeat connections in PADS Logic and speed the processof connecting to a bus.

17. Choose the ( Duplicate icon ) from the toolbar.

18. Select the midpoint of the D01 connection you added. A copy of the connection attaches to the cursor.

19. From the pop-up menu, choose Step and Repeat. The Step and Repeat dialog box appears.

20. Select Down as the Direction, type 6 in the Count text box, type 100 in the Distance text box.

21. Choose OK to complete the connection of U7 to the data bus.


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2.8 Changing Schematic Data

You can change objects, including their placement and properties, at any time in the design cycle.

Exercise 9: Properties, Rename Net and Part

Query or Modifying Schematic Data :

Use the Properties mode editing capabilities to modify text strings, bus names, reference designators, andmost other types of data in your schematic.

1. Choose File / Open / Samples previewbus.sch.

2. Search for U7 by typing the modeless command su7 and pressing Enter.

3. Select the 28MHz netname label for the off-page symbol above U7.

4. Choose the (Properties icon) from the toolbar

The Net propertiesdialog box appears.

5. Choose Statistics. A net statistics report appears in the default text editor. Your query should showthat the 28MHz net is only a single pin net. It is connected to U7 pin 1 but not to any other device.This is because the netname is incorrect.

6. Close the report file.


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Rename a Net :

Using editing features of the Net Propertiesdialog box, you can rename the net .

7. With the Net Propertiesdialog box open, type 24MHZ in the Net Name text box.

8. Choose This instance, and choose OK

9. Because this net already exists, the messageNet already exists -OK to combine nets?appears. Choose Yes to combine the nets and remove the single pin net.

10. Repeat the step 2 to 5 , see the difference .


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Rename a Part:

You can use similar operations for renaming nets to rename a part. You query a part and change itsreference designator.

11. Select sheet POWER .

12. Choose the (Properties icon) from the toolbar.

13. Search for R500 by typing sr500 and pressing Enter. PADS Logic automatically changes from sheet1 (Logic) to sheet 2 (Power) and locates the part.

14. Zoom in around R500 and select the resistor symbol. The Part Propertiesdialog box appears.

15. Choose Rename Part, and type C10.


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Exercise 10: Changing Part Information

Change Part Types :

The next step changes the component type for the R500, and make it a capacitor. This is accomplished

using the Properties Partdialog box to change its part type to a capacitor.

1. Choose the ( Properties icon ) from the toolbar

2. Select the part symbol rather than the name label. The Part Properties dialog box appears.

3. Choose Change Type from the Part Type area. The Change Part Type dialog box appears.

4. Type cap* in the Items text box of the Filter area and choose Apply. All of the capacitors

available in the libraries appear in the Part Types list in the Change Part Type dialog box.

5. Choose CAP1206 from the Part Type list box and choose This Part from the Apply Update Toarea. ( You can update all parts use this part-type ).

6. Choose OK to change the resistor to a 1206 style capacitor.( Note: The default orientation in the library becomes the new orientation for the part. )


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Updating one Capacitance Part Value :

To change the capacitance of a capacitor and Capacitor C10s orientation does not match the other

capacitors. This is because R500 was rotated and mirrored when it was added to the schematic.

7. With the Properties Part dialog box open, choose the Attributes icon from the Modify area. TheProperties Part Attributes dialog box appears.

8. The Attributes area lists several Names and Values. Currently, the Value cell next to the Value namecontains ???. Choose the ??? Value cell, then choose Edit.

9. Type .1 uf in the Value cell.

10. Choose This Part from the Apply Update To area.

11. Choose OK to complete the edit and automatically update C10-CAP1206 capacitors to .1 uf only

12.Choose Close to close the Part Properties dialog box.


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Exercise 11: Grouping

Group Copy :

You can import and export groups of circuitry to and from other schematics. You can also group, copy,move, or delete blocks of circuitry within a schematic diagram. The first step is to define the group you'll

work with.

1. Choose the ( Select Anything ) from object selector tool bar

2. Select Capacitor (C1C10), Power and Gnd signal.

( Click and hold the left mouse button and drag the cursor to define a selection area thatencloses the items that you want to group. When you release the mouse button, the selected

items are highlighted . )

3. Right-click and choose Duplicate from the pop-up menu to copy the defined group. The groupattaches to and follows the cursor.


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Move thegroup copyto position X: 8700, Y: 3200 on this page of the schematic, and then click to place it.

Reference designator name of group copy region will reassigned.

Group Saved and Pasting :

You can save thegroup copyto a file (from the edit menu) for use in other schematics by selecting copy to

file instead of group copy. To paste a group into a design, select paste from file from the edit menu, and

select desired group file listed.

4. Repeat step 1 to 2 .

5. Right-click and choose Save to Filefrom the pop-up the Edit menu. The Group Save File dialog boxappears.

6. Type a name copy_group in the File Name area.


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7. Choose Save.

8. Choose Edit/Paste From File. The Load Group File dialog box appears.

9. Choose the file copy_group from the list , and Choose Open.

10. The Group is attached to the cursor. Select the location X:10600 ,Y:5700 .

11. The group is placed at the current cursor location. If the design contains parts with the same referencedesignation as those in the group, the new parts reference designation of group will rearrangement and

a report is generated.

12. Press OK to Complete.


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2.9 Generating Reports

Defining design rules lets you place constraints on critical design areas. Any design rule defined in PADS

Logic is maintained in PowerPCB. Design rules include clearance, routing, and high-speed constraints

assigned as a default conditiona condition or option that is set when PowerPCB startsor for nets,

layers, class groups, or pin pairs. You can also assign conditional design rules and differential pairs.

Conditional design rules come into play when one object, such as a net, is routed near another specifiedsignal.

Exercise 12: Creating a Netlist, Export to PADS Layout and BOM

Creating a netlist is the typical method for passing schematic data into PowerPCB as layout data. A

netlist contains a list of the parts and their part types and all of the nets. Optionally, it can also include all

design rules.

Creating a netli st:

1. Choose File / Open /Samples previewrules.sch

2. Choose Tools/Layout Netlist. The Netlist dialog box appears.

3. Accept the default settings in the Netlist to PCB dialog box and choose OK to create the netlist. Whenyour definition of the netlist is complete, the netlist file appears in your default text editor.

4. Review the contents of the netlist file and close the report file before proceeding to the next section.


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Export to PADS Layout:

5. Start PADS Layout by choosing ( PADS Layout icon) on Desktop.

6. Choose File / Import C:\Project files\Samples\ previewrules.asc

7. Press OKto accept the warning.

8. Press Tools/Disperse Componentand OKto place component , you can see the all component andnet connection base on PADS Logic setting.


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9. Press Setup/Design Rule, Check theclearance rules, Conditional Rule , Routing Rulesand somesetting is same as Logic.

Compili ng of Bill of Materi als :

The Bill of Materials looks into the part type data for every part in the design and arranges the information

in a parts schedule format. You can customize the report by entering unique column headers and

specifying the width of the column:

10. Return PADS Logic environment.

11. Choose File/Report. The Reports dialog box appears.

12. Select Bill of Materials from the Select Report Files for Output area.

13. Choose Setup. The Bill of Materials Setup dialog box appears.

14. Choose the Attributes tab and select Reference in the Field Header column.

15. Change the values according following setting .

Choose OK in the Reports dialog box. The Bill of Materials report appears. Take a moment to review thecontents of the bill of materials report. When you are through, close the report file.


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3 PADS Logic Library

In this lesson youll learn how to create library elements that compose a parttype in the PADS Logic

library using the Part Editor in PADS Logic.

Understanding the PADS Logic Part Type. Creating a Pin Decal.

Creating a CAE Decal.

Creating a new Part Type.

Before you can add a part to a schematic, it must exist as a PowerPCB/PADS Logic part type in the library.

A part type is composed of these three elements:

The logic symbol or CAE decal as it is called in the PADS Logic library.

A PCB decal, such as a DIP14.

Electrical parameters, such as pin numbers and gate assignments.

An example of a PowerPCB/PADS Logic part type is a 7404.

Part type name: 7404

CAE decal: INV

PCB decal: DIP14

Electrical parameters: Six logical gates (A through F) using 12 of the 14 pins with one power pinand one ground pin.

CAE decal PCB decal

The Part Editor

You can create a part type in PADS Logic or in PowerPCB; however, you can only create a CAE decal in

PADS Logic, and you can only create the PCB decal in PowerPCB.

Use the Part Editor to create and modify standard schematic symbols such as gates, resistors, capacitors,

connectors, etc., and special symbols such as ground, power and off-page references. You also use the PartEditor to create new CAE decals, pin decals, and assign PCB decals; the physical representation of the partin a PCB design system.

Choose Tools/Part Editorto enter PADS Logic's Part Editor. Unneeded menu commands and toolbar

icons are removed or replaced with menu commands and toolbar icons specific to creating and modifying

parts.


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A PADS Logic part is comprised of three elements:

Part Type The electrical information for a part such as a 74LS02 , This includes the logicfamily, CAE Decal assignment, part name, connection pins, gate swapping

information, etc.

CAE Decal The CAE decal is the logic symbol that appears on the schematic; for example, aNAND gate.

PCB Decal The graphical representation of the part when it is drawn in the PCB design

program. It is often referred to as the footprint. Assigning a PCB Decal is optional

and only required if you are passing a netlist to PowerPCB or Perform.

Lines General graphical data you can store in the library, such as a company logo, to use

in any .sch file.

CAE Decals

Each part added to a schematic must have a CAE Decal to graphically represent the logical function of thepart. While some parts are represented entirely with a single CAE decal, some parts are composed ofmultiple instances, such as the multigated inverter mentioned above.

A CAE decal is composed of pin decals attached to terminals placed at intervals around a graphic symbol

that represents the logical function of the device. The terminals can also have pin names that are the logical

function of the pin, such as IN, OUT, or VSS.

All of the elements of a CAE decal are created in PADS LogicsPart Editor.


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2. Choosing CreateNew Libto Create a new library and naming to

For example : Your student no. is 12345678d.

Manage the Library List Order

When you add a part to the design, you are actually retrieving information about that part from the

library. The Library List dialog box contains a list of libraries to search. The libraries are searched in

the order in which they are listed, beginning with the first library in the list.

3. Choosing Manage Lib list, select the library and press UPbottom torearrangement the select position of library


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3.2 Creating a CAE Decal

In this exercise you will use the CAE Decal Wizard and other features to create a CAE decal for the

87C256 part type.

Exercise 14: Creating a CAE Decal

1. Choosing Tools/Part Editor.

2. In the Part Editor. Choose File/New. The Select Type of Editing Item dialog box appears.

3. Choose CAE Decal and choose OK.

Once you open the CAE Decal Editor, some text labels and a CAE decal origin marker appear.

Each of these labels are placeholders for CAE decal-related text objects. The position of these labels on the

CAE decal determines where the CAE decal text object appears in the schematic. The origin marker serves

as the origin for moving or positioning the CAE decal on the schematic.

REF The placeholder for the reference designator. (U1 , C1 , R1 ,etc)

PART-TYPE The placeholder for the part type (7404, 74LS74, etc.).

*Free Label 1 The placeholder for the first displayed part type attribute.

*Free Label 2 The placeholder for the other displayed part type attribute.

Note: An attribute, in PowerPCB/PADS Logic terminology, is a specific type of part information

that can be included in the parts library description and exported to a parts list. Examples are part

manufacturer, package type, and order number.


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CAE Decal Wizard :

Define a simple pin decal consisting of a horizontal line and a small circle. This is a symbol that typically

represents a logical NOT input or output.

4. Choose the Drafting icon from the toolbar to open the Drafting toolbox

5. Choose the CAE Decal Wizard from the Drafting toolbox..

6. In the Box Parameters area, type 800 in the Min Width text box.

7. In the Left Pinsarea, choose PIN as the Pin Decal and type 19 in the Pin Count text box.

8. Type 0 in the Right Pin, Upper Pin, and Lower Pin text boxes for pin count.

9. Choose OK to create the CAE Decal.

Adding New Termi nals :

At this stage, the CAE decal is not complete. You must add output pins and modify some of the symbols

on the input pins. You will use the terminal commands to add output pins to the CAE decal.

10. Choose the ( Add Terminal icon ) .


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17. Choose OK to complete the Step and Repeat command.

18. Press Esc to exit the Add Terminal operation.

Modif ying Terminals :

Now, you have added the output pins, use the other terminal commands to modify the input pin

arrangement and complete the CAE decal. The input pins consist of 15 address inputs, 3 controlinputs

and one extra input pin. The pin decals for two of the control inputs need modification and you must

remove the extra terminal.

19. Choose ( Change Pin Decal icon ) The Pin Decal Browse dialog box appears.

20. Choose the PINBpin decal you created earlier from the Pins list box.

21. Choose OK.


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22. You are now in a pin decal assignment mode. Any terminal that you select is assigned the PINNOTpin decal. Select the two bottom input terminals on the left side of the part (terminals #18 and #19) to

change the pin decal on both from PIN to PINB.

23. Remove the extra terminal by choosing the Delete icon from the toolbar and selecting the fourthterminal from the bottom (terminal #16). The terminal numbers following terminal #16 are

renumbered to accommodate the deletion.

24. Choose View/Extents to fit the completed decal in the view.

Save the CAE decal:

To save the CAE decal to the library:

25. Choose File/Save. The Save Item to Library dialog box appears.

26.Navigate to the C:\Mentor Graphics\9.34PADS\SDD_HOME\Libraries\library, and type 87C256 in the Name of Item text box.

27. Choose OK. PADS Logic saves the CAE decal and makes 87C256 the CAE current decal.


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3.3 Creating a New Part Type

Now you will create a 87C256 part type by combining the 87C256 decal with its electrical properties and

by assigning a PCB decal. Perform this process in the Part Editor using the part type editing functions.

Exercise 15: Creating a New Part Type

Create part type in the Part Editor.

1. Choosing Tools/Part Editor.

2. Choose File/New

3. Choose Part Type in the Select Type of Editing Item dialog box, and then choose OK.

Assign a Family Type:

The first step in creating a part type is to assign the family type for the part.

4. Choose ( Edit Electrical icon ) from the toolbar. The Part Information dialog box appears.

5. Choose the General tab.


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6. In the Logic Family area, select TTL to assign it as the family type for the part type.This also assigns a default reference designator prefix of U.

Assign a PCB Decal :

The next step is to assign the 87C256 CAE decal and a 28- pin PCB decal.

7. Choose the PCB Decals tab.

8. Select the \..\libraries\common library in the Library list box.

9. Set the Filter to DIP*, type 28 in the Pin Count text box, and choose Apply.

10. Select the DIP28-600PCB decal, and choose Assign to assign the PCB decal as the first (and only)PCB decal for the part type.

( DIP28-600 means that IC is use dual i n l ine package and i ts width is 600mil )


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Assign a CAE Decal :

11. Choose the Gates tab, and choose Add to add the first (and only) gate of the part type.

12. Double-click in the CAE Decal 1 text box or choose Edit. A Browse button (...) appears.

13. Choose the Browsebutton to select a CAE decal from the library.

14. Select the C:\Mentor Graphics\9.34PADS\SDD_HOME\Libraries\12345678 library from theLibrary list box.

15. Type * in the Filter text box, and choose Apply.

16. The 87C256 CAE decal appears in the Unassigned Decals list box.

17. Select the 87C256 decal in the Unassigned Decals list box and choose Assign. The decal moves intothe Assigned Decals list box.

18. Choose OK to complete the operation.

Assign Signal Pins:

Next, assign the standard power and ground pins (or signal pins, as they are called in PADS Logic

applications).

19. Choose the Pins tab in the Part Information dialog box.

20. Change Pin Group of pin 14 from Unused Pin to Signal Pin.

21. Change Pin Group of pin 28 from Unused Pin to Signal Pin.

22. Double-click in the Name text box for pin 14. Type GND.


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23. In the Name text box for pin 28, type +5V.

Add User-defi ned Attr ibutes:

Finally, you will add user-defined part type attributes.

24. Choose the Attributes tab, and then choose Add.

25. Choose Browse Lib Attr. The Browse Library Attributes dialog box appears.

26. Select Description and choose OK.

27. Press Tab to switch to the Value cell and type 32K X 8 BIT CMOS EPROM/LATCH.

28. Choose Add, and Browse Lib Attr again and repeat the previous steps to add the attributes andvalues as below:


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29. When you complete the addition of all attributes, choose OK to complete the entry of the electricalparameters for the part type.

If an error message appears Gate A Decal 87C256 has 26 terminals but gate definition has 0

pins , Closed the message and continue. This message isexpected because the user does not

define all pin names by Part Information tools.

Assigning Pin Numbers and Pin Names to Gates:

At this stage the part type is nearly complete. You still need to assign pin numbers and pin names to theterminals in the CAE decal. This is why the decal appears to have missing terminals.

30. Choose ( Edit Graphics icon ) from the toolbar then choose OK to select Gate A (the only gate)from the Gate list box.

If a warning message appears regarding gate pins not being equal to terminals, choose OK to

dismiss the message and continue. This message is expected because pins are not assigned to the

gate.

31. Choose the (Decal Editing Toolbar) icon from the toolbar to open the Terminal Toolbox.

32. Choose ( Set Pin Name icon ) from the Terminal toolbox. The Start Name dialog box appears.

33. Type Q0 in the dialog box and choose OK.

34. Select the top-most output pin (on the right side of the component) to assign its pin name as Q0.

35. Select the output pin just below pin Q0, and assign its pin name as Q1.


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36. Select the remaining output pins, in order, to assign the names Q2 through Q7.

37. Choose the ( Set Pin Name icon ) again, type A0 in the Start Name dialog box, and chooseOK.

38. Select the top-most input pin (on the left side of the component) to assign its pin name as A0.

39. Select the input pin just below the A0 pin to assign its pin name as A1.

40. Select the remaining input pins, in order, to assign the names A2 through A14.

41. Choose the Set Pin Name icon, and type ALE/ \CE in the Start Name dialog box. Do not use spacesin the pin name.

42. Choose OK.

43. Select the input pin below A14.

44. Choose the Set Pin Name icon, and type \OE in the Start Name dialog box.

45. Choose OK.

46. Select the next input pin.

47. Choose the Set Pin Name icon, and type VPP in the Start Name dialog box.

48. Choose OK.

49. Choose ( Set Pin Number icon ) , type 1 in the Start Number of a Terminal dialog box andchoose OK. Select the VPPpin to assign its pin number as 1.

50. Select the A12pin and assign it pin number 2. Continue selecting pins, in the order shown in thefollowing graph. Stop after you assign a pin number to pin Q2. Proceed to the next step.

51. Select pin Q3. After you have selected pin Q3, it is assigned as pin 14. Pin 14 was previouslyassigned as a signal pin for GND in the electrical parameters. To change Q3 pin number to 15, select

pin Q3 again, the next highest pin number is assigned to it.


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52. Select pin Q4 to assign it as 16. Continue assigning the pin numbers to the remaining pins

Save the Part Type :

To save the part type to the library:

53. Choose File/Return to Part. The message returning to Part levelKeep changes to Gate appears.

54. Choose Yes to save the gate changes and return to the Part Editor.

55. Choose File/Save. The Save Item to Library dialog box appears.

56.Navigate to the C:\Mentor Graphics\9.34PADS\SDD_HOME\Libraries\

library, and type 87C256 in the File Name text box.

57. Choose OK. PADS Logic saves the Part Type and makes 87C256 current part type.

58. You completed the 87C256 part type. Choose File/Exit Part Editor to exit from the Part Editor andreturn to the Schematic Editor


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3.40 Test The New Part Type

Now you create a Part :87C256 part and link to PADS Layout use by netlist .

Exercise 16: Link to PADS Layout

1. Add the 87C256 and 74LS373 to LOGIC use add part command

2. Connect Q0Q7 to D0D7 as the following diagram.

3. Choose Tools/Layout Netlist. The Netlist dialog box appears.

Save to C:\PADS Projects\TESTLINK.ASC


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4. Accept the default settings in the Netlist to PCB dialog box and choose OK to create the netlist. Whenyour definition of the netlist is complete, the netlist file is open in your default text editor.

5. Review the contents of the netlist file and close the report file before proceeding to the next section.

6. The report shows that U1 has a part 87C256(Logic Decal) and its references to PADS Layout withSO28(PCB Decal).

Export to PADS Layout:

7. Start PADS Layout by choosing ( PADS Layout icon) on Desktop.

8. Choose File / Import C:\PADS Projects\TESTLINK.ASC

9. Press OKto accept the warning.

10. Press Tools/Disperse Componentand OKto place component, you can see that all components andnet connections are placed according to the PADS Logic setting.


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Reassign the PCB Decal i n Logic Part :

11. Return to PADS Logic

12. Select 74LS373, right click mouse and select Properties.

13. Select PCB Decals, Assign PCB Decals to SO20WB., Press OK.

14. Choose Tools/Layout Netlist.

15. Repeat the step from 3 to 10 , You can see the change of U2 .

16. In PADS Layout, you can see the difference of the Part change .


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3.5 L ibrary Practical Task 1

Now, you can try to create a library item for Microcontroller PIC18F4520and save it to library.

Exercise 18 : Creating a Microcontroller

Pin Diagr ams of PIC18F4520 :

40-Lead Plast ic Du al In-l ine (P) 600 mil Bo dy (PDIP)


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The final result is shown as the following diagram.


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Now, you can try to create a library item for Transistor, and save it to library

Exercise 19 : Creating a Transistor

Transistors SS8050 datasheet:

Create a part and save to library as shown below :


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a. Choose Tools/Part Editor input the new name to SS8050

b. Choose (Decal Editing Toolbar) Right click to invoke short-cutmenu click and select circle .

c. Set design grid and Press S 0 0 point to origin .

Draw the cir cle -

Left-click a point as centre and drag the circumference until the diameter = 400mil .Note that we set the Display Dot Grid = 100 mil beforehand and estimate the diameter of

Circle with reference to the Display Dot Grid.

Draw the 2D l ines -

Set design grid to10 mil , Right click to invoke short-cut menu click , select path and any

angle, 1stleft-click specifies the starting point, drag the line to the desired end point, double

left-click can terminate the line.

The position of line is ( -100 ,100 -100,-100 ) , (-100,0 -200 ,0 ) ,

( -100,0100,170 ) , ( -100,0 100,-170 ) .

Drag the line as below:


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Draw the fi ll ed polygon :

G10Right-clickpolygonAny Angle (the edge of polygon can be rotated by any

angle)draw the polygon as below :

Fi ll the polygon

Select Select the polygon Right-clickPropertiesselect Filled

d. Add Terminal as below :


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f. Save Part and Gate Decals as

g. Place the parts 2N3636 adjacent to SS8050, and connect them together as below:

h. Check the netlist, you will notice that the alphanumeric characters can be used in thenaming.


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i. Open PADS Layout to import the netlist, and check if the netlist is successfully createdbefore.


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Now, you can try to create a library item for Relay.

Exercise 20 : Creating a Relay

Create a part and save to student_exec.lib as shown below :

The Part type name : RLY-RLY11_DPDT

The PCB Decal : RELAY3

The Value : RELAY-12V

The Reference Designator : K

Check i f the netli st is successfu ll y created by importi ng i t into PADS Layout.


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4 Hierarchical Design

H ierarchical Design

PADS Logic supports the hierarchical symbol for the schematic, or to define a hierarchical symbol and the

underlying logic. You can also assign or unassign in the Query Hierarchical Component dialog box.

You can navigate the hierarchy with the View/Push Hierarchy and View/Pop Hierarchy commands. Whena hierarchical symbol is copied, all of the underlying logic represented by the symbol is also copied. PADS

Logic updates the reference designator names of the underlying symbols. There is a one-to-one

correspondence between hierarchy symbols and a schematic sheet. The underlying logic for duplicated

hierarchical symbols is stored as a unique sheet, and can be edited without affecting the logic of other

hierarchical symbols.

Creating a Hi erarchical Symbol

Choose the New Hierarchical Symbol icon from the Design toolbox to start the process. The Hierarchical

Symbol Wizard appears.

Exercise 21 : Create a Hierarchical Symbol

1. Open a new Sheet , set Sheet size to A4 , and Design grid and Display grip to 100 mil .

2. Select ( Design ) ( new hierarchical symbol ) , the Hierarchical SymbolWizard dialog box appears .

3. Type the symbol name HALFADD_A in the Sheet Name text box

4. Choose OK. The hierarchical symbol appears in the Part Editor window. An input or output pin isadded in the symbol for each off-page reference. Type the pin name as below :


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5. When complete the hierarchical symbol, select File/Complete to close the part editor, the new symbolis attached to the cursor.

6. Add the hierarchical symbol to worksheet and add off-page.

Pushing I nto the H ierarchy

Use the View/Push Hierarchy command to look inside or push down into a hierarchical symbol to view the

underlying logic.

7. Choose the View/Push Hierarchy command from the menu.

8. Select the hierarchical symbol and press enter. It opens a new worksheet.

9. Draw a logic diagram as below :


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10. Choose the View/Pop Hierarchy command from the menu and return to main worksheet.

11. Duplicate the hierarchical symbol and connect them together as below .

12. Choose the View/Push Hierarchy command from the menu to open the HALFADD_B, you will findthat the logic diagram is same as HALFADD_A , and the reference designator has been re-arranged.

13. Save the file as Hierarchical.sch .


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4. Select printer and paper size then press OKto print the drawing.


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6 Integrated Exercise 1

You are required to create a schematic diagram as shown in Page 82 to Page 109:

Complete your diagram with the following requirements:

1. Configure sheet size to A3.

2. Almost all parts can be found in the enc_training.lib, but some parts are missing in the library,you need to create the missing parts and complete the schematic diagram.

3. Edit the Part value. For simplicity, we only need to make Part Value and Ref. Designator visible.The Part Type should be hidden.

4. Select the PartRight ClickVisibilityuncheck all the attributes.

5. Save the schematic diagram as IExx.sch , the xx is Page number.


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7 Integrated Exercise 2

Revert PCB to Schematic Diagram

Sometime we need to revert PCB layout to schematic diagram and modify the circuit!

For example :

If you have a PCB layout as below:

You can easily convert it to a Schematic diagram.


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Try to complete the other circuit and save to revert.sch


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8. Drawing Exercise


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pads logic

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