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Advanced Layout & Routing Techniques
The document presents advanced layout and routing techniques by EMA Design Automation, focusing on various electrical and physical constraints within PCB design, such as differential pairs, impedance, and propagation delays. It includes a detailed discussion on the constraint manager, flex routing, and reuse technologies, along with practical demos and examples. The content aims to enhance the effectiveness of design processes through automation and efficient management of design constraints.
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Overview of presentation focus on customer requirements, quality products, and technical support.
Outline of topics including Constraint Manager, Flex Routing, and technical demos related to PCB design.
Details on types of constraints managed including Electrical, Physical, and Design constraints in PCB design.
Information on analyzing physical and spacing constraints, displaying element info alongside rules.
Explanation of electrical constraints in OrCAD and Allegro including Total Etch Length and Differential Pair.
Introduction to differential pairs, naming conventions, auto setup in tools for efficient PCB design.
Detailed definitions and constraints of differential pairs including width, gap, and tolerance settings.
Exploration of routing strategies for differential pairs in PCB design focusing on options and guidelines.
Usage of visual guides and constraints to manage differential pairs effectively, including length tuning.
In-depth look at various electrical constraints like wiring and propagation delays applicable in Allegro.
Introduction to flex routing techniques in PCB designs, particularly for multi-line applications.
Information on technology files that help in managing design-level constraints and preserving standards.
Methods for reusing designs including front-to-back design reuse and placement replication techniques.
Overview of CircuitSpace, its features, and how it integrates into PCB editors for enhanced functionality.
How CircuitSpace manages component clusters and templates, facilitating efficient design replication.
Thank you note and invitation to contact EMA for more information on products and services.
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Advanced Layout & Routing Techniques
- 1. Advanced Layout &Routing Techniques Presented By: Janine Flagg Sr. Field Applications Engineer eMail: JanineF@ema-eda.com Customer promise… Our focus today, as it was in 1989, is to meet our customers’ requirements with quality products, leading technology, and exceptional technical support.
- 2. 2 © 2014EMA Design Automation. EMA confidential. Agenda • Constraint Manager • Constraint Resolution • Electrical Constraints − Differential Pairs − Total Etch Length − Wiring − Vias − Impedance − Min/Max Propagation Delay − Relative Propagation Delay • Flex Routing • Reuse − Technology Files − Front-to-Back Design Reuse − Placement Replication − CircuitSpace • Demos − Differential Pair Routing − Total Etch Length – Delay Tune − Multi-Line Routing (Flex) − Placement Replication − Front-to-back Design Reuse − CircuitSpace
- 3. Constraint Manager •Constraint Manager includes five types of constraints: – Electrical Constraints: Performance characteristics – Physical Constraints: Line width, via selection, and layer restrictions – Spacing Constraints: Clearances between lines, pads, vias, and copper areas (shapes) – Same Net Spacing Constraints: Clearances between lines, pads, vias, and copper areas (shapes) on the same net – Design Constraints: Package to package checks, soldermask & pastemask checks and negative plane island checks • Physical and Spacing include two categories of constraints: – Default Rules: Used to specify rules to be applied to nets that have no special routing requirements – Special Rules: Nets that require unique constraints 3 © 2014 EMA Design Automation. EMA confidential.
- 4. Constraint Manager Interface Setup > Constraints > Constraint Manager … or … 4 © 2014 EMA Design Automation. EMA confidential.
- 5. Constraint Manager AnalysisModes Analyze > Analysis Modes > Electrical Modes OrCAD PCB Designer Professional Allegro PCB Designer 5 © 2014 EMA Design Automation. EMA confidential.
- 6. Constraint Resolution Physical • Top displays element 6 © 2014 EMA Design Automation. EMA confidential. information – Description – X/Y location – Net name • Bottom displays constraint rules – Constraint set name – Constraint set rules – Constraint values Display > Constraint Single select
- 7. Constraint Resolution Spacing • Top displays element 7 © 2014 EMA Design Automation. EMA confidential. information – Description – X/Y location – Net name • Bottom displays constraint rules – Constraint set name – Constraint set rules – Constraint values Display > Constraint Drag Select
- 8. Electrical Constraints OrCADPCB Designer Professional • Total Etch Length Constraint • Differential Pair Constraints – Uncoupled Length 8 © 2014 EMA Design Automation. EMA confidential.
- 9. Additional Electrical Constraints Allegro PCB Designer • Wiring Constraints ‒ Net Scheduling ‒ Parallelism ‒ Layer Sets Rules 9 © 2014 EMA Design Automation. EMA confidential. • Via Constraints − Max Via Count − Matched Vias • Impedance • Min/Max Propagation Delays • Differential Pair - Static Phase Tolerance • Relative Propagation Delay
- 10. Differential Pairs •Net Naming Convention • Auto Setup of Differential Pairs in OrCAD Capture • Auto Generation of Differential Pairs in PCB Editor • Defining Differential Pairs in Constraint Manager • Anatomy of a Differential Pair • Physical Differential Pair Constraints • Electrical Differential Pair Constraints • Differential Pair Routing Options • Working with Differential Pairs 10 © 2014 EMA Design Automation. EMA confidential.
- 11. Differential Pairs SignalNaming Convention for Auto Setup Naming Rules for Signals within Differential Pairs Examples: • SignalName_P SignalNameP SignalName_N SignalNameN SignalName_H SignalNamaH SignalName_L SignalNameL SignalName_+ SignalName+ SignalName_- SignalName- 11 © 2014 EMA Design Automation. EMA confidential.
- 12. Differential Pairs AutoSetup in OrCAD Capture Tools > Create Differential Pair > Auto Setup 12 © 2014 EMA Design Automation. EMA confidential.
- 13. Differential Pairs AutoGenerate in PCB Editor Logic > Assign Differential Pair > Auto Generate… 13 © 2014 EMA Design Automation. EMA confidential.
- 14. Differential Pairs Definingin Constraint Manager Create > Differential Pair… 14 © 2014 EMA Design Automation. EMA confidential.
- 15. Anatomy of aDifferential Pair Primary Line Width • The trace width that should be used to route the differential pair nets the majority of the time • The width you prefer your differential pairs to be routed Min Line Width 15 © 2014 EMA Design Automation. EMA confidential.
- 16. Anatomy of aDifferential Pair Primary Gap • The Spacing, edge to edge, that should be used to route the differential pair nets the majority of the time • The rule you prefer your differential pairs to follow • This only applies to the two differential pair nets. Other net spacing to the differential pair nets is controlled by the Spacing Rule set Line to Line clearance Primary Gap 16 © 2014 EMA Design Automation. EMA confidential.
- 17. Anatomy of aDifferential Pair Neck Width and Neck Gap • Rules to be applied when the traces must “squeeze” down to be routed between pins/vias (for example, in BGA areas) • Neck Gap is the new spacing, edge to edge, that should be routed to route the differential pair • Neck Width is the new trace width that should be used to route the differential pairs Neck Width 17 © 2014 EMA Design Automation. EMA confidential. Neck Gap
- 18. Anatomy of aDifferential Pair Separation Gap Tolerance • Coupled Tolerance (+)/(-) ‒ Provides a coupling range based on the Primary Separation Gap ‒ Summing Primary Separation Gap and Coupled Tolerance (+) provides the maximum coupled gap ‒ Subtracting Primary Separation Gap and Coupled Tolerance (-) provides the minimum coupled gap ‒ Values above or below these become an uncoupling event Primary Separation plus (+) Tolerance 18 © 2014 EMA Design Automation. EMA confidential. Primary Separation minus (-) Tolerance Primary Separation Gap
- 19. Anatomy of aDifferential Pair Minimum Line Space • For the differential pair itself • If set, this value must be less than your Primary Gap minus the Coupled Tolerance Minus value • Use this value to override the Spacing Constraint set line-to-line 19 © 2014 EMA Design Automation. EMA confidential. value Min Line Spacing
- 20. Anatomy of aDifferential Pair Max Uncoupled Length • Maximum length of uncoupled trace summed throughout the entire differential pair route • See green etch below: Gathered Ungathered 20 © 2014 EMA Design Automation. EMA confidential.
- 21. Anatomy of aDifferential Pair Gather Control • Choices are Include & Ignore • Controls whether or not to include the etch length from pin to gather point when calculating Max uncoupled length 21 © 2014 EMA Design Automation. EMA confidential. Include OR Ignore this total length This length is ALWAYS included Gather points
- 22. Anatomy of aDifferential Pair Static Phase Tolerance • Allowable difference in length between the differential pair nets • When the Phase Tolerance Value is -1 (unspecified), phase checking is disabled Length of net A Length of net B Note: Available only in Allegro PCB Designer and above. 22 © 2014 EMA Design Automation. EMA confidential.
- 23. Differential Pairs PhysicalConstraints • Differential Pair Constraints set in the Physical Domain 23 © 2014 EMA Design Automation. EMA confidential.
- 24. Differential Pairs ElectricalConstraints • Differential Pair Constraints set in the Electrical Domain 24 © 2014 EMA Design Automation. EMA confidential.
- 25. Differential Pairs RoutingOptions 25 © 2014 EMA Design Automation. EMA confidential. Horizontal Vertical Diagonal Up Diagonal Down Route > Connect
- 26. Differential Pairs RoutingOptions • Once seeded, it is possible to route tandem differential pairs as well as edge coupled. 26 © 2014 EMA Design Automation. EMA confidential.
- 27. Working with DifferentialPairs • Pseudo-segments graphically show uncoupling errors in the board – Once the length of uncoupled etch exceeds the set value, every segment that is uncoupled is highlighted in this way • Red and Green Meter guides the routing of Differential Pairs and signals with Length Constraints – Static Phase Tolerance – Total Etch Length Note: Meter available only in Allegro PCB Designer and above. 27 © 2014 EMA Design Automation. EMA confidential.
- 28. Electrical Constraints TotalEtch Length • May be assigned to a Net, Xnet, Bus or Differential Pair • Both Min and Max are etch length values with optional units • If no units are specified, drawing units are assumed • Either value is optional – May specify only Min, or only Max 28 © 2014 EMA Design Automation. EMA confidential.
- 29. Electrical Constraints TotalEtch Length - Delay Tune • Use the Delay Tune function to add length • May also be used to match the length of a group of nets 29 © 2014 EMA Design Automation. EMA confidential.
- 30. Electrical Constraints Wiring- Topology & Stub Length Note: Available only in Allegro PCB Designer and above. 30 © 2014 EMA Design Automation. EMA confidential.
- 31. Electrical Constraints Wiring- Layer Sets & Exposed Length Note: Available only in Allegro PCB Designer and above. 31 © 2014 EMA Design Automation. EMA confidential.
- 32. Electrical Constraints Wiring- Parallel Note: Available only in Allegro PCB Designer and above. 32 © 2014 EMA Design Automation. EMA confidential.
- 33. Electrical Constraints Vias- Via Count & Match Vias Note: Available only in Allegro PCB Designer and above. 33 © 2014 EMA Design Automation. EMA confidential.
- 34. Electrical Constraints Impedance Note: Available only in Allegro PCB Designer and above. 34 © 2014 EMA Design Automation. EMA confidential.
- 35. Electrical Constraints Min/MaxPropagation Delays Note: Available only in Allegro PCB Designer and above 35 © 2014 EMA Design Automation. EMA confidential.
- 36. Electrical Constraints RelativePropagation Delay Note: Available only in Allegro PCB Designer and above 36 © 2014 EMA Design Automation. EMA confidential.
- 37. 37 © 2014EMA Design Automation. EMA confidential. Flex Routing • Flex Board
- 38. • Multi-Line Routingis used for Flex Routing 38 © 2014 EMA Design Automation. EMA confidential. Flex Routing
- 39. Reuse Technology Files • Technology files (tech files) contain: ‒ Parameters ‒ Design-level constraint data ‒ Constraint Modes ‒ Cross-section ‒ User-defined properties • Stored on disk • Preserve company standards while creating new databases • Results reported in techfile.log 39 © 2014 EMA Design Automation. EMA confidential.
- 40. Reuse Technology File- Export File > Export > Techfile… 40 © 2014 EMA Design Automation. EMA confidential.
- 41. Reuse Technology File- Import File > Import > Techfile… 41 © 2014 EMA Design Automation. EMA confidential.
- 42. Reuse Front-to-Back DesignReuse • Circuits may be placed, routed and saved for design reuse • Requires the use of external Hierarchy in OrCAD Capture Hierarchical block placed at top level schematic is referencing an external design that has already been placed and routed in PCB Editor and saved as a Reuse Module 42 © 2014 EMA Design Automation. EMA confidential.
- 43. Reuse Front-to-Back DesignReuse • Reuse Modules may be placed as if they were one component 43 © 2014 EMA Design Automation. EMA confidential.
- 44. Reuse Placement Replication • Available in Placement Application Mode only • Allows creation of seed circuits • May be replicated ‒ Within the current design ‒ From one design to another 44 © 2014 EMA Design Automation. EMA confidential. • May include: ‒ Component Placement ‒ Related Routing ‒ Local Shapes ‒ Reference Designator Placement
- 45. Reuse Placement Replication Step 1 and 2 Create original circuit and select components Step 5 Enter a name for the Module Definition File and Save 45 © 2014 EMA Design Automation. EMA confidential. Step 4 Hover over a pin and RMB – Snap pick to - Pin Step 3 Hover over a component and RMB – Place replicate create, then RMB - DONE
- 46. Reuse Placement Replication Step 1 Window - select targeted components 46 © 2014 EMA Design Automation. EMA confidential. Step 4 Place replicated circuits Step 2 Selected components a pin and RMB – Place replicate apply – module name
- 47. • CircuitSpace plugsinto Cadence Allegro and OrCAD PCB Editors as a command menu • Is not accessible as a separate executable • Menu is available to the left of PCB Editor’s Help menu 47 © 2014 EMA Design Automation. EMA confidential. Reuse CircuitSpace
- 48. • CircuitSpace addsthe following to the PCB Editor: ‒ CircuitSpace pull-down menu ‒ CircuitSpace properties ‒ CircuitSpace documentation • Driven from within the native layout application • Engine actions are non-blocking • Uses “verb/noun” command structure • Implements Right-Mouse-Button pop-up menu ‒ With options for the current command 48 © 2014 EMA Design Automation. EMA confidential. Reuse CircuitSpace
- 49. Reuse CircuitSpace –Schematic Data • Edit Board Parameters form specifies type of schematic data to be used ‒ Allegro HDL ‒ Allegro CIS ‒ Mentor DxDesigner ‒ PDF ‒ None = Rooms 49 © 2014 EMA Design Automation. EMA confidential.
- 50. Reuse CircuitSpace -Clusters • CircuitSpace “Clusters” components based on schematic the information provided: • Clusters may be ‒ Moved & Rotated ‒ Mirrored ‒ Automatically Placed ‒ Replicated ‒ Aligned ‒ Merged ‒ Saved as a “Template” • Templates may be: ‒ Applied to multiple channels within a design ‒ Applied to multiple designs 50 © 2014 EMA Design Automation. EMA confidential.
- 51. Reuse CircuitSpace –Auto Placement of Clusters • Single-Sided Auto Placement • Double-Sided Auto Placement 51 © 2014 EMA Design Automation. EMA confidential.
- 52. Reuse CircuitSpace –Propagating Placement • Propagating Placement across clusters 52 © 2014 EMA Design Automation. EMA confidential.
- 53. Reuse CircuitSpace –Previewing Templates • Templates may be previewed before applying 53 © 2014 EMA Design Automation. EMA confidential.
- 54. Reuse CircuitSpace –Applying Templates • Etch may be mapped to the desired layers on the target board 54 © 2014 EMA Design Automation. EMA confidential.
- 55. Thank You ForJoining Us Call us today! To find out about the latest in new product developments, training, educational opportunities, and services offered call EMA, a Cadence Channel Partner and Autodesk authorized value added reseller at 800.813.7287 or visit us online at www.ema-eda.com. 55 © 2014 EMA Design Automation. EMA confidential.