哪里获得xc7z015的许可证

嗨，大家好。
当我在vivado 2013.4中运行xc7z015clg485时，它会报告
'错误：[通用17-69]命令失败：您的设备许可证'xc7z015'仅用于评估或试用目的。
此许可证禁用比特流创建。
请运行Xilinx许可证配置管理器以获取有关确定系统许可的功能和设备的帮助。
执行时
“write_bitstream -force system_wrapper.bit”
“
虽然我的PC上的许可证可以成功运行xc7z020和xc7z030但是它无法完成xc7z015的“生成比特流”。在license.xilinx.com中我找不到xc7z015的许可证，我在哪里可以获得许可证
对于xc7z015？



以下为原文

Hi Every One.
when I run xc7z015clg485 in vivado 2013.4,it reports
'ERROR: [Common 17-69] Command failed: Your license for device 'xc7z015' is setup for evaluation or trial purposes only. Bitstream creation is disabled for this license. Please run the Xilinx License Configuration Manager for assistance in determining which features and devices are licensed for your system.    while executing"write_bitstream -force system_wrapper.bit "'Though the license in my PC can ran the xc7z020 and xc7z030 successfully, it can't finish the "generate bitstream" for  xc7z015.In the license.xilinx.com I can't find the license for xc7z015,Where can I get the license for xc7z015?