大家好：
我遇到了这样一个问题，最近刚开始使用28377，在CCS下仿真时总是报错，用示波器测试TRST和TCK都是低电平。报如下故障
Error connecting to the target:
(Error -2131 @ 0x0)
Unable to access device register. Reset the device, and retry the operation. If error persists, confirm configuration, power-cycle the board, and/or try more reliable JTAG settings (e.g. lower TCLK).
(Emulation package 6.0.407.3)
检查硬件电路没有什么问题，唯一不确定的就是两个bootpin脚没有上下拉电阻，但我认为这个对于仿真调试应该不影响
我用的仿真器是XDS200的USB，target配置为Texas Instruments XDS2XX USB Debug Probe，使用的是controlSUITE代码例程
使用test connection报告如下：
[Start: Texas Instruments XDS2xx USB Onboard Debug Probe_0]
Execute the command:
%ccs_base%/common/uscif/dbgjtag -f %boarddatafile% -rv -o -S integrity
[Result]
-----[Print the board config pathname(s)]------------------------------------
C:\Users\ADMINI~1\AppData\Local\TEXASI~1\
CCS\ti\0\0\BrdDat\testBoard.dat
-----[Print the reset-command software log-file]-----------------------------
This utility has selected a 560/2xx-class product.
This utility will load the program 'xds2xxu.out'.
The library build date was 'Jul 27 2016'.
The library build time was '17:54:51'.
The library package version is '6.0.407.3'.
The library component version is '35.35.0.0'.
The controller does not use a programmable FPGA.
The controller has a version number of '13' (0x0000000d).
The controller has an insertion length of '0' (0x00000000).
This utility will attempt to reset the controller.
This utility has successfully reset the controller.
-----[Print the reset-command hardware log-file]-----------------------------
This emulator does not create a reset log-file.
-----[An error has occurred and this utility has aborted]--------------------
This error is generated by TI's USCIF driver or utilities.
The value is '-233' (0xffffff17).
The title is 'SC_ERR_PATH_BROKEN'.
The explanation is:
The JTAG IR and DR scan-paths cannot circulate bits, they may be broken.
An attempt to scan the JTAG scan-path has failed.
The target's JTAG scan-path appears to be broken
with a stuck-at-ones or stuck-at-zero fault.
[End: Texas Instruments XDS2xx USB Onboard Debug Probe_0]
正常的打印信息我在网上查过，应该在“”This emulator does not create a reset log-file.“地方应该是
“This scan-path will be reset by toggling the JTAG TRST signal
........等等
请哪位大侠能帮忙分析一下，感激不尽
