Cross-Reference File (.xrf) Definition
An ASCII text file (with the extension .xrf), that is generated by a third-party synthesis tool, and which allows the Quartus® Prime software to locate or cross-probe an object from the Quartus® Prime source design file to the third-party tool source design file.
The Cross-Reference File provides mapping information between signals or components used in the third-party generated source file and signals or components used in the Quartus® Prime design source file.
The Cross-Reference File has the same name as the Quartus® Prime project, and is located in the Quartus® Prime project directory.