Issue link: https://resources.pcb.cadence.com/i/1310866
www.cadence.com 2 Allegro PCB Design Solution PCB Editor Technology Constraint-Driven PCB Editing Environment At the heart of Allegro PCB Designer is a PCB Editor—an intuitive, easy-to-use, constraint-driven environment for creat- ing and editing simple to complex PCBs. Its extensive feature set addresses a wide range of design and manufacturability challenges: • A powerful set of floorplanning and placement tools including placement replication for accelerating placement of the design • Powerful shape-based shove, hug interactive etch creation, editing establishes a highly productive interconnect environment while providing real-time, heads-up displays of length and timing margins • Dynamic shape capability offers real-time copper pour plowing and healing functionality during placement and routing iterations The PCB Editor can also generate a full suite of phototooling, bare-board fabrica- tion, and test outputs, including Gerber 274x, NC drill, and bare-board test in a variety of formats. Constraint Management A constraint management system dis- plays physical/spacing and high-speed rules along with their status (based on the current state of the design) in real time and is available at all stages of the design process. Each worksheet provides a spreadsheet interface that enables users to define, manage, and validate the different rules in a hierarchical fashion. With this powerful application, designers can graphically create, edit, and review constraint sets as graphical topologies that act as electronic blueprints of an ideal implementation strategy. Once they exist in the database, constraints can drive the placement and routing processes for constrained signals. The constraint management system is completely integrated with the PCB Editor, and constraints can be validated in real time as the design process proceeds. The result of the validation process is a graphi- cal representation of whether constraints pass (highlighted in green) or fail (high- lighted in red). This approach allows designers to immediately see the progress of the design in the spreadsheets, as well as the impact of any design changes. Floorplanning and Placement The constraint and rules-driven method- ology of PCB design solutions includes a powerful and flexible set of place- ment capabilities, including interactive and automatic. The engineer or designer can assign components or subcircuits to specific "rooms" during design entry or floorplanning. Components can be filtered and selected by reference desig- nator, device package/footprint style, associated net name, part number, or the schematic sheet/page number. With thousands of components compris- ing today's boards, precise management is critical. Real-time assembly analysis and feedback can facilitate this manage- ment—helping designers increase productivity and efficiency by placing components according to corporate or EMS guidelines. Dynamic DFA-driven placement offers real-time package- to-package clearance checking during interactive component placement (see Figure 2). Driven from a two-dimensional spreadsheet array of classes and package instances, real-time feedback provides minimum clearance requirements. Based on the package's side-to-side, side-to- end, designers can simultaneously place devices for optimum routability, manufac- turability, and signal timing. Placement Replication Superior placement replication technology within Allegro PCB Designer allows users to quickly place and route multiple similar circuits in a design. It allows users to create a template using one instance of placed and routed circuit that can be applied to other instances within the design. The saved placement template can be used with other designs where similar circuits are used. When replicating placement, users can flip or mirror the circuit from top layer to bottom layer. All associated etch elements, including blind buried vias, are mapped to correct layers when circuit is moved from top layer to bottom layer. Display and Visualization The built-in 3D viewer is available in all PCB Editor products. The 3D environment supports several filtering options, camera views, graphic display options such as solid, transparency, and wireframe, and mouse-driven controls for pan, zoom, and spinning the display. 3D viewing also sup- ports the display of complex via structures or isolated sections of the board. Multiple display windows can be opened using the context sensitive command structure, and 3D images can be captured and saved in JPEG format. (See Figure 3.) The flipboard capability "flips" the design about its Y axis inverting the design data- base in the canvas. This "flip" reorganizes the display of the design such that what was displayed as top through to bottom becomes bottom through to top. Having a true bottom side view from within the CAD system is essential for hardware Figure 2: DFA rules-driven placement allows for compact placement of components without introducing errors