开发板连接ccs出现错误~请教高人解答

自己做的开发板,仿真机是XDS560PLUS
用JTAG口连接,连接时出现了以下错误

Trouble Reading Register:
Error 0x80002044/-275
Fatal Error during: Register, Initialization, Control,  
This error was generated by TI\'s USCIF driver.

SC_ERR_SCN_POLL_BUSY <-275>
The utility or debugger has requested that a target DSP or micro-
controller 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.


Sequence ID: 5
Error Code: -275
Error Class: 0x80002044


不知道是什么原因.....

之前还有2次连不上,都是电源方面引起的.....修改后,重连,连上了,但是再断电重连时就出现了以上的错误,之后就再也连不上了....请大家不吝赐教~