1. Device for processing a stream of data words received from a data source at one input, wherein the data words are buffered in a first FIFO memory, further comprising an interface for outputting the data words in data packets of a defined format, and comprising a processor for generating request packets for controlling the interface or an external device via the interface, wherein the request packets are buffered in a second FIFO memory, wherein said data packets and request packets are transferred to the interface via the same data lines, comprising a multiplexer unit, that mixes data packets and request packets in a manner according to a priority scheme, so that a preset data packet length for the data transmissions to the interface is respected.