Stmicroelectronics Gmbh

Howard Gurney

William P Robbins

Andrew R Dellow

Fabrizio Simone Rovati

Andrew MacCormack

David Lewis

A system comprising first input means for receiving a transport stream from an external source, second input means for receiving an input from a memory, means for connecting the first and second input means to an interface which is arranged to provide an output stream to a decoder. The second input means is arranged to provide an output to the interface in such a form that the interface does not distinguish between the output from the first and second input means.

System for receiving transport streams

A monolithic semiconductor integrated circuit is provided for selectively encrypting or decrypting data transmitted between one of a plurality of devices on the circuit and an external memory. Two series of data pathways connect the devices and the external memory. The first series of data pathways passes through a cryptographic circuit causing data to be encrypted or decrypted, and the other series of data pathways provides an unhindered route. When a data access request is made by a device, the data is selectively routed along one of the two series of data pathways according to the identification of the device making the data access request. In one example, if data is transmitted from a device to the external memory, the data is selectively encrypted before being stored in the external memory if the device transmitting the data is identified as secure. Then, when that data is retrieved from the external memory by a second device, the data is selectively decrypted only if the second device is identified as secure.

Monolithic semiconductor integrated circuit and method for selective memory encryption and decryption

The present invention relates to the demultiplexing of a digital data stream in a receiver so as to retain only those parts of the digital data stream required by the receiver. Such demultiplexing is particularly useful when applied to a receiver circuit in a television system having a digital set-top-box. A memory in the receiver stores packet identifiers of data packets required by the receiver, which are stored in the memory under the control of a first control circuit. A second control circuit extracts packet identifiers from incoming data packets in an input digital data stream. A third control circuit receives the extracted packet identifier and determines whether this matches one of the packet identifiers stored in the memory. A match signal is set by the third control circuit to the second control circuit responsive to a match. The second control circuit demultiplexes the input data packet responsive to the match signal.

Digital receiver demultiplexer

This invention relates to a device and method for producing a stream of data. The device receives a stream of data as an input and includes means for identifying a portion of the input stream and outputting the identified portion. The device also includes means for selecting a further portion of the input stream and outputting the selected portion. The relative timing between the two output streams is monitored and maintained with respect to the input stream.

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Bristol, United Kingdom

Howard Gurney