Using Multiple SDC Files

The Efinity software v2023.1 and higher allows you to use multiple SDC files in your project. You add additional SDC files in the Project Editor. SDC files are processed in the order listed.

During compilation, the software reads the SDC files in order starting from the first listed file and continuing to the next one(s). The same constraint order rules apply to the SDC file list. The software displays messages about the SDC file(s) in the Console. The software reads the files at the beginning of the routing stage. If the software detects any errors in the SDC file(s), it shows the error, file name, and line number.

In the Efinity software v2024.2 and higher you can use the set sdc_list Tcl command in your top-level SDC file to reference additional SDC files outside of your project.

set sdc_list { <file> <file> <file> ... }

For example, use the following Tcl syntax in the top-level SDC file to read the referenced files file1.sdc, file2.sdc, and file3.sdc:

set sdc_list { file1.sdc file2.sdc file3.sdc }

foreach f $sdc_list {
    source $f
}

The software reads the SDC files in the order you have listed in the set sdc_list command. Ensure that you list them in the correct order.

Important: Because they are not added to your project, the Efinity software does not know about the referenced SDC files and cannot track changes to them. For example, if you change an SDC file that is in your project, the Efinity software recognizes there has been a change and prompts you to re-compile. However, if you change a referenced SDC file, the software does not recognize that a change happened and does not prompt a re-compile. This situation could cause unintended effects. Therefore, be careful when using referenced SDC files and always re-compile when you modify them.