System and method for interfacing a transport decoder to a national renewable security systems (NRSS) smart card

Abstract

A transport decoder 110, for receiving and processing a transport data stream using MPEG-2 formats, includes connections to a physical layer channel interface (channel interface) 112, a buffer memory 114, a host microprocessor 116, audio and video decoders 118/120, and clock signal circuitry 122. The transport decoder also includes an interface to a decoder which does not include a "data valid" input terminal. Upon receipt of encoded data packets, the transport decoder recognizes a frame synchronization byte and transfers an encoded data packet to an external decoder via the interface. The transport decoder sets a count value for a predetermined number of bytes in the encoded data packet and sends the packet data to the external decoder. When the specified number of bytes have been sent to the external decoder, the transport decoder determines if another synchronization byte has been encountered. If another synchronization byte has been found, the transport decoder continues to send encoded data to the decoder. Otherwise, the transport decoder sends zero-valued data to the external decoder.

Dependencies are inferred from the claim text.