The NuMicro® Family microcontroller (MCU) supports In-System-Programming (ISP) function allowing the embedded Flash memory to be reprogrammed under software control. ISP is performed without removing the microcontroller from the system through the firmware and on-chip connectivity interface, such as USB, I²C, SPI, CAN,RS485,BLE,WiFi.Before using the ISPTool, user needs to program the ISP code into LDROM by using a universal programmer or Nuvoton’s NuMicro® ICP Programming Tool, and the User Configuration bit ‘CBS’ configured as Boot from LDROM.ISPTool came with two different modes. One is the GUI mode, which is more user friendly, with an easily to use front end allowing user to control with simple mouse click. The other one is command line mode, this mode is suitable to combine with shell script for automation control.