If the Nu-Link driver is not installed, the following error screen will appear when using Keil.
First, please download the Nu-Link driver from the Nuvoton official website:
After installing the driver, please select the installation path of the correct Keil version. As to the default path, use Keil5 development environment and select Keil_v5; if you use Keil4 development environment, please select Keil as shown below.
After the installation is complete, the following window will appear. Select the Nu-Link USB Driver in the red box shown below to install the driver that allows the computer to receive the UART through VCOM.