A user-defined device is any device not made by Altera that can be added to the JTAG chain in the Quartus® Prime software. You must specify the properties of the user-defined device, such as register lengths and the JTAG ID code, within the Programmer for the Quartus II software to recognize the device. The properties of a user-defined device are stored within a Quartus User-Defined Device (.qud)file. Once you add the device to a JTAG chain and define it, the Programmer can treat the device as a bypass device and work around it while programming other devices. When you install a new release of the Quartus II software, the Import User-Defined dialog box and Export User-Defined dialog box allow you to move the information about the user-defined device from one version of the Quartus® Prime software to another.