Components and macros can be placed in the editing area either automatically or manually. When you use automatic placement (AutoPlace), the system selects an appropriate site or sites for each component or macro you select for placement. When you use manual placement, you select both a source component or macro and the destination site in which to place it.
The automatic placement software selects sites based on routability. You can automatically place selected components or macros or automatically place all remaining unplaced components in the design.
You can also unplace components and macros. Unplacing unroutes each net pin on the components or macros you select, then removes the components and macros from the editing area and adds them to the list of the design's unplaced components or macros.
The following sections describe placing and unplacing components and macros.
You can automatically place components and macros by using the Autoplace command. You can automatically place selected components or all remaining unplaced components.
To automatically place selected components, perform the following procedure.
Use one of these methods to automatically place all unplaced components.
When you autoplace all remaining components within EPIC, no existing routing unrouted and rerouted to accommodate the new placement. Because PAR unroutes components, if necessary, placement done with PAR produces different results than placement done in EPIC. PAR places components more efficiently, and a densely packed design can more easily be placed and routed with PAR than with EPIC.
Figure 3.20 Autoplace All Attributes Dialog Box |
The fields in this dialog box are as follows.
Coarse Placement | Performs a quick placement, with little regard for efficiency. Coarse placement places the entire design much faster than a placement at a selected level (see Place at Level field following), but the resulting placement may not be suitable for routing. Select the Coarse Placement field to quickly place a design to see how it maps, but not route the resulting placement. |
Place at Level | Effort level at which the design is be placed. The level ranges from 1 (Least Difficult) to 5 (Most Difficult) with intermediate ranges 2, 3, and 4. |
Cost Table | Cost table (1 - 100) to use for placement at the level specified by the Place at Level field. |
Disable Timing Driven | Turns off timing-driven placement. |
There are three manual placement procedures.
To manually place an unplaced component, follow this procedure.
The component is placed in the site. If the Automatic Routing Option is On, the component is routed after it is placed.
To move a component or swap components, follow the procedure described in the Moving and Swapping Components and Macros section. To manually place or swap a macro, see the Manually Placing Macros section of the Working with Physical Macros chapter.
The Unplace command removes selected components and macros from their current sites. You can also unplace all placed components and macros in the design. To unplace macros, see the Placing and Unplacing Macros section of the Working with Physical Macros chapter.
Before unplacing a component, the system unroutes each component pin on the component. You can display a list of unplaced components in the EPIC List dialog box. Unplaced components and macros can be placed.
Locked components cannot be unplaced.
To unplace selected components use the following procedure.
To unplace all placed components and macros in the design use one of these methods.
All placed components and macros in the design, except locked ones are unplaced.