Hi Chuan-Yu,
As of R2021a there is a stateful-classify block in Simulink. The Stateful Classify block predicts class labels for the data at the input by using the trained recurrent neural network specified through the block parameter. This block allows loading of a pretrained network into the Simulink® model from a MAT-file or from a MATLAB® function. This block updates the state of the network with every prediction.
Regards,