7.10 Managing Synthesis Attributes

This feature allows you to add or modify the synthesis attributes of the SmartDesign objects (nets, ports, and instances) directly from the SmartDesign canvas.

Important: Synthesis attributes are not allowed to be set on BIF pins, BIF nets, pin groups, and slices. User-defined attributes are not supported.

Synthesis attributes that apply to the component can only be set on SmartDesign canvas. In the generated HDL file, those attributes are added to the SmartDesign module or architecture.

The following table lists the synthesis attributes available in the Synopsys® FPGA synthesis tool that are supported by SmartDesign.

Table 7-7. List of Synthesis Attributes
Attribute Object
syn_insert_buffer Port, instance
syn_keep Net
syn_maxfan Port, net, instance
syn_no_compile_point Module or architecture
syn_noclockbuf Port, net, module or architecture
syn_noprune Instance, module or architecture
syn_preserve Port, module or architecture
syn_hier Module or architecture
Important: For more details for each attribute, see Synplify Pro® ME.

To add, modify, or remove synthesis attributes of the SmartDesign objects, perform the following steps:

  1. Click Manage Synthesis Attributes icon in the SmartDesign toolbar. The Synthesis Attributes window appears.
    Figure 7-33. Synthesis Attributes
    Graphical user interface, application Description automatically generated
  2. Select any object of interest such as a port, net, or instance in the SmartDesign canvas, the attributes of the selected object is displayed in the Synthesis Attributes window.
  3. You can perform the following actions:
    Action Steps
    Add attributes From the Name dropdown list box, select the synthesis attribute of your choice. The synthesis attribute is automatically added with a default value. The selected synthesis attribute description is displayed at the bottom of the window.
    Modify attributes Double-click the Value field of the synthesis attribute and change the default value as required.
    Remove attribute

    Click to select the synthesis attribute you want to remove and click –. To remove all synthesis attributes, click X. Alternatively, right-click on the port, net, or instance that has synthesis attributes and select Clear Synthesis Attributes.