Abstract: A circuit generally including a control function and a checksum function is disclosed. The control function may be configured to assert (i) a start signal in response to a signal having a predetermined sequence of values matching an entry value and (ii) a stop signal in response to the signal matching an exit value. The checksum function may be configured to (i) generate a checksum value for the signal between assertions of the start signal and the stop signal and (ii) generate a result signal in response to comparing the checksum value with an expected value.

Abstract: A circuit generally comprising a control function and a checksum function is disclosed. The control function may be configured to assert (i) a start signal in response to a signal having a predetermined sequence of values matching an entry value and (ii) a stop signal in response to the signal matching an exit value. The checksum function configured to (i) generate a checksum value for the signal between assertions of the start signal and the stop signal and (ii) generate a result signal in response to comparing the checksum value with an expected value.

Abstract: An optical disk system is presented which stores disk- and user-specific settings, along with an associated method. The optical disk system includes a disk drive unit for retrieving identification data and encoded video data stored upon an optical disk, an input device for inputting user settings, and a microprocessor memory unit having a non-volatile portion for storing the identification data and the user settings. Information specific to optical disks (e.g., DVDs) and users is stored within the non-volatile portion of the microprocessor memory unit. The user settings may include, for example, spoken language, video display format, audio volume setting, and subtitle language. The user settings may be retrieved and invoked, conveniently allowing a user to view a presentation (e.g., a movie), or to continue viewing an interrupted presentation, without having to reselect viewing and listening preferences. The identification data may include a portion of a title of the optical disk.