Open Block Library for the STM32 Nucleo Boards
You can open the STMicroelectronics® Nucleo boards block library in two ways.
At the MATLAB® Command prompt - This approach is quick, but does not display the other Simulink® block libraries that are available.
In the Command Window, enter
stmnucleorootlib.The STM Nucleo library opens.

Note
You can click on the Common block or the Utilities block icons in this window to open the blocks from the respective block libraries.
In the Command Window, enter
stmnucleolib.The STM Nucleo Common block library opens.

In the command window, enter
nucleoutilitieslib.The STM Nucleo Utilities block library opens.

By using the Simulink Library Browser - Open a Blank Simulink model.
On the Simulink® Editor toolbar, click the Library Browser

icon.
In the Simulink Library Browser, locate and select the STM32 library on the library pane. The blocks available for Nucleo appear on the right pane of the Simulink Library Browser.