If you do not have Vivado or ISE software installed already on your system, search on IP Center for the product page for the core.
A core which requires a license key will either have a Get License option on the main product page (for a no charge IP) or instructions in the Evaluate or Order link on the product page that indicate that a license key is required.
Open CORE Generator and look in the License column of the IP catalog.
Any LogiCORE IP Core that requires a license key will show a small padlock icon beside it in this column.
A $ symbol on the padlock icon indicates that the license key must be purchased.
A padlock icon without a $ symbol indicates that the license key is available at no additional cost to licensed ISE customers.
Log in to the Xilinx Product Licensing site to generate a key.In the Vivado IDE