我做了50套板子，其中有20套板子下载都正常，但是也有大部分用impact下载失败，提示如下。

INFO:iMPACT - Current time: 2015/2/4 11:30:48
PROGRESS_START - Starting Operation.
INFO:iMPACT:583 - '1': The idcode read from the device does not match the idcode in the bsdl File.
INFO:iMPACT:1578 - '1': Device IDCODE : 00000100000001100100000010010011
INFO:iMPACT:1579 - '1': Expected IDCODE: 00000100000000000100000010010011
PROGRESS_END - End Operation.
Elapsed time = 0 sec.

如果我用initialize chain则是检测在位置设备：

Attempting to identify devices in the boundary-scan chain configuration...
INFO:iMPACT - Current time: 2015/2/4 11:33:28
PROGRESS_START - Starting Operation.
Identifying chain contents...INFO:iMPACT:1588 - '0':The part does not appear to be Xilinx Part.
'0': : Manufacturer's ID =Unknown , Version : 2
INFO:iMPACT:501 - '1': Added Device UNKNOWN successfully.
----------------------------------------------------------------------
----------------------------------------------------------------------
done.
PROGRESS_END - End Operation.
Elapsed time = 0 sec.

请各位大神们指点下，帮组下小弟。