1. An information processing system comprising: a control central processing unit; a memory; and a stream interface configured to receive an input stream including data to be processed and transfer the input stream to the memory, wherein a download process in which the stream interface receives stream data including firmware and stores the stream data in the memory is executed in response to an instruction from the control central processing unit, and the control central processing unit analyzes the stream data stored in the memory to extract the firmware in the memory space and executes the firmware extracted in the memory space to process the data to be processed.