Using Design Goals and Strategies

ISE

You can use Xilinx® Design Goals and Strategies to help you achieve your design goals. Design Goals and Strategies control the implementation tools by using preset process properties designed to achieve a particular design goal.

Design Goals and Strategies

A Design Goal is a category that corresponds to a particular implementation goal. Each Design Goal includes one or more Design Strategies. A Design Strategy contains process properties that are set to achieve a Design Goal. Each Design Strategy is stored in a datafile with a .xds file extension.

You can use the predefined Design Goals and Strategies provided with the ISE software, or you can create custom Design Goals and Strategies, as described in Creating or Editing a Design Strategy. Following are some the Design Goals and Strategies provided with the ISE software:

Balanced - provides a balanced implementation of timing performance and runtime. This setting is the default for all new projects and includes the default values for all process properties.
Minimum Runtime - attempts to meet timing constraints as well as reduce runtime.
Power Optimization - attempts to meet timing constraints as well as reduce power consumption.
Timing Performance - attempts to meet timing constraints as much as possible. It performs additional optimization and uses higher effort levels to try to achieve timing performance, based on your timing constraints. This extra effort will most likely increase runtime.

Note If you have user constraints in your design, the software attempts to meet these constraints regardless of the Design Goal or Strategy. However, the effort at which the software attempts to meet these constraints varies based on the Design Goal and Strategy.

To Apply a Design Strategy

To apply a Design Goal and Strategy to your project, do the following:

Select Project > Design Goals & Strategies.
In the Design Goals and Strategies dialog box, select the Design Goal.
Select the Strategy.
Click OK.

To View Process Properties for a Design Strategy

You can view process property settings from the Design using either of the following methods:

In the Design Goals and Strategies dialog box, click View Strategy Details.
In the Processes pane of the Design panel, right-click a process, and select Process Properties.
This allows you to view the process properties in the individual Process Properties dialog boxes. Process properties that are set as part of a Design Strategy show a lock icon next to the property, indicating that the property is read-only or locked. To modify these properties, you must unlock the Design Strategy or create a custom Design Goal and Strategy, as described in Creating or Editing a Design Strategy.

To Unlock a Design Strategy

Process properties that are set as part of a Design Strategy are read-only or locked and cannot be modified. When you unlock a Design Strategy, all of the process properties associated with the Design Strategy are unlocked and you can modify them as needed. To unlock a Design Strategy, do the following:

in the Design Goals and Strategies dialog box, select the Unlock option.
Click OK.

It is important to note that at this time there is not a Design Strategy applied. In the Design Goals and Strategies dialog, the “Last applied Goal and Strategy” field will tell you what the last applied Strategy was, but there is no guarantee at this time that the properties from that Design Strategy are still set in the project.

Note When using the Balanced Design Goal, process properties are set to their system default values and are not locked.

To Create a Custom Design Strategy

You can use the Design Goals and Strategies Editor to edit or create your own Design Goals and Strategies, as described in Creating or Editing a Design Strategy. This topic also describes how to apply the custom Design Strategy to your project.