A demultiplexer for separating different format packets from a multiplexed data stream. Each packet format has a different type of header which is analyzed based on micro-codes read out in sequence from a command memory. By using micro-codes, the demultiplexer minimizes the circuitry required to process multiple formats (e.g. digital video broadcasting (DVB), digital satellite system (DSS), and digital versatile disc (DVD)). The packets are separated and sent to their respective destinations based on the packet ID read from each header.