Synchronizing the Layout Database with a Design

Use the following procedure to import a layout from a PADS layout.

Prerequisite

After exporting the FPGA from PADS I/O Designer to the schematic; generate a netlist in PADS Designer, forward changes to PADS layout, and save layout in PADS.

1. Select File > Database Properties and, if necessary, click the Netlist Source page.

2. Select Schematic as the Netlist source and click OK.

3. In PADS I/O Designer, select Import > Layout to populate the layout database from the schematic.

The Layout Window shows the netlines in the design and the Layout Scenarios Window opens with an “Initial Scenario”, as shown in Figure 10-2.

Figure 10-2. Components Imported Into Layout

4. With the layout database open, select Tools > IOD Components. The devices available for I/O optimization are listed here.

Visibility of each component can be turned off and on using the Visibility control, or mirrored by checking the Mirror control.

5. (Optional Step) You can filter the components, such that only those you want to use in the PADS I/O Designer optimization process are imported. Select File > Database Properties and click the Component Filter page. Use regular expressions to specify the reference designators of the unwanted components.

Components can now be moved around freely inside the Layout Window. Next, optimization can be performed using Unravel Nets and different scenarios can be created until the best solution is found and applied (see "Creating and Applying a Layout Scenario").