In order to deploy your Simulink model onto an Arduino board, you need only MATLAB, Simulink, and the Simulink Support Package for Arduino, which can be downloaded from the link below:
However, if you want to view the generated code, you need both MATLAB Coder and Simulink Coder.
Once the Simulink model is built with the above mentioned toolboxes and deployed on the target hardware, a folder is generated which contains the generated code for you to view.
You can find an example on how to get started with Simulink and Arduino on the following link to the MATLAB documentation:
