DFA Spreadsheet

Introducing Real Time DFA Analysis
CDNLIVE! 2005
Ed Hickey
Cadence Design Systems
Sept 13, 2005
1 CADENCE DESIGN SYSTEMS, INC.

Introduction
• Ed Hickey - Cadence Design Systems
– ehickey@cadence.com
• Allegro Product Engineer
– 5 years at Cadence
– 19 years in Product Design/EDA (Data General, Foxboro, Zuken)
– International Cadence User Group History
– CDN Champion (Liaison, advisor to BOD)
– MVP 2003 - Best Practices with Dynamic Shapes
– MVP 2004 - Modernization of NC Drill Environment
2

Agenda
• Real Time DFA Analysis
– Overview of New Application
– Dynamic Clearance Feedback
• Overview of DFA Rules based Spreadsheet
– Classification Editor
– Controls
• Adoption Consideration
– Library Migration
– DFA_Update Utility
• Demonstration
3

Real Time DFA – Overview
• New technology inside Allegro PCB Editor offering real time
package to package clearance analysis during interactive
placement
• Driven by a rules-based Spreadsheet supporting:
– Package Side to Side; End to End; Side to End profile checking
– Top and Bottom side parameters
– Symbol Classification User Interface
– Read-only option
• Licensed to Allegro PCB Editor 610 (Expert), 620
4

Real Time DFA – Graphical Feedback
• Feedback in the form of a spacing circle provides minimum
distance to package side or end
5

Real Time DFA – Interactive Placement
• Feedback Integrated with Place
Manual Command
– Not aligned with generic Move
command
• New place icon added in 15.5
(emulates place – manual–hide)
• Also new in 15.5
– New Filters added to Place
Manual User Interface
– Component Association
Structures
6

Real Time DFA - Package Side and End
• Keys off new DFA placebound or legacy placebound shape
• The software determines the package side and end based on
the longer and shorter dimensions of the package symbol
• Shape must be a rectangle for system to distinguish between a
side or end
E
S
S
E
E
S
E
S
7

Real Time DFA – Possible Combinations
Syntax = S-S; E-E; S-E
• Side to Side
• End to End
• Side to End
8

Real Time DFA - Indeterminate Packages
• If the software cannot determine the side or end, it uses the
most conservative value of the string entered in the spreadsheet
for that particular package to package requirement
• Examples
9

Real Time DFA - Most Conservative Rule
• The largest value of the
string is considered
“most conservative”
• The cell syntax can
consist of a single entry
for all sides
Most Conservative
10

DFA Spreadsheet - Overview
• 2-Dimensional Array of
package-package spacing
requirements
• Syntax support for Side to
Side; End to End; Side to
End Profile Checking
• Class or Instance Level
Support
• Top/Bottom Side
Parameters
• Read-only option prevents
end user from editing table
11

DFA Spreadsheet – How to Launch
• From Allegro PCB Editor
- Setup > DFA Constraint Spreadsheet
• As a stand-alone application
- Command - DFA_DLG
- Does not consume license
- Use for development purposes
- Writes class info to library
12

DFA Spreadsheet – Class Hierarchy
• Class objects appear at the
top of the list, ahead of
symbol instances
• Identified by a blue bounding
box around cells
• Classes contain families of
symbols with common
spacing criteria
• Reduces number of entries
in Spreadsheet
Class Editor
13

DFA Spreadsheet - Classification Editor
• Create new Class names
• Displays all symbols and
current class structures from
PSMPATH or Database
• Cut-Paste support
– Cut symbol from ‘pkg-sym’ list
– Paste into class
• Updating Library with
dfa_device_class property
restricted to stand-alone
version of Spreadsheet
14

DFA Spreadsheet - Controls
• Purge Classified Symbols – removes Class based package
instances from spreadsheet
• Purge Unused Symbols – removes symbols not present in
database
• Copy Top Table to Bottom – Copies top entries to bottom side
• Read-Only – Prevents end user from editing spreadsheet values
15

Adoption - Updating Symbols
• DRC keys off new DFA
placebound shape
• Traditional placebound will be
used if DFA_PLACEBOUND
does not exist
• DFA_Update utility provides
migration solution
– Quickly adds new DFA
placebound shapes to .dra files
– Compiles .psm
– Instance or wildcard updating
– Optional class attributes
16

Constraint Manager – Reporting DRCs
• New DRC Reporting Worksheets (15.5)
• Itemized list of errors per DRC category
• Cross Probe to Allegro Editor
17

User Preference Settings
• New DFA_DRC category
– DFA Pause control
when placing
component to min
spacing
– Display No DRC
Markers on Spacing
Bubble
18

Design Path Variable
• DFACNSPATH used
for search-path to DFA
Spreadsheet
• Works with DFA
command
– File > Browse DFA
Library
19

20
Product Demonstration