jtag无法识别

INFO: [Labtools 27-2285] Connecting to hw_server url TCP:localhost:3121
ERROR: [Labtoolstcl 44-26] No hardware targets exist on the server [localhost]
Check to make sure the cable targets connected to this machine are properly connected
and powered up, then use the disconnect_hw_server and connect_hw_server commands
to re-register the hardware targets.
jtag的绿灯不亮，请坛主帮忙！

当uknown device 右击查看属性，有pid vid 说明硬件被系统识别了，但是没有合适的驱动程序。一般安装VIVADO 或者ISE 有默认勾选的驱动安装复选框，如果么有勾选，或者勾选了，杀毒软件禁止安装了，可能出现以上故障。
拔掉USB下载器，双击install_drivers.exe安装驱动包：百度网盘：链接：http://pan.baidu.com/s/1kVPdHaR 密码：ruqq