连接显示如下错误：但是我在建立连接文件.ccxml时候test connection是成功的，请问这是为什么
The attempt to poll a target device exceeded its timeout limit.
The utility or debugger has requested that a target device be
repeatedly accessed for a specific data or status value.
This has failed because the built-in limit for the maximum number
of attempts when polling the JTAG scan-path has been exceeded.
(Emulation package 7.0.100.0)
