在debug中运行程序一段时间后，Expressions中变量值会突然无法被观察，并且console窗口出现以下提示：
C28xx_CPU1: JTAG Communication Error: (Error -150 @ 0x0) One of the FTDI driver functions used during configuration returned a invalid status or an error. (Emulation package 9.3.0.00058)
C28xx_CPU1: Breakpoint Manager: Unable to remove requested AET job
C28xx_CPU1: Failed to remove the debug state from the target before disconnecting. There may still be breakpoint op-codes embedded in program memory. It is recommended that you reset the emulator before you connect and reload your program before you continue debugging
