在自己的板子上调试报错如下，demo板上调试正常：
Cortex_M3_0: Error: (Error -1170 @ 0x0) Unable to access the DAP. 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 8.0.903.2)
Cortex_M3_0: Trouble Halting Target CPU: (Error -2064 @ 0x0) Unable to read device status. 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 8.0.903.2)
另外还发现一个奇怪现象，用Flash Programmer 2擦除flash后，第一次调试能正常进行，但第二次调试又出现如上错误。
