As of R2018b, it partially supports multi-instance SWCs. Take a look into de Embedded Coder AUTOSAR user guide (https://www.mathworks.com/help/releases/R2018b/pdf_doc/ecoder/ecoder_autosar.pdf section 2-11) or AUTOSAR Blockset user guide for newer versions. It says that Multi-Instance Components are supported except when the model contains either of the following blocks:
• Simulink Function
• Model-level Inport configured to output a periodic function-call
However, if you are trying to create the model from an imported arxml file, bad news, after the importer command is requested, MATLAB will produce an error which basically ask you to set the attribute supportsMultipleInstantiation of the component's SwcInternalBehavior to false.
Actually I'm struggling myself with this import issue, I see that your post has been here for a while so in case you have found a workaround, I would really appreciate if you could share.
Best regards
