Abstract: An interrupt controller for a microprocessor having a plurality of event memories which are combined to form at least one group and each having an input for a setting signal and an output for an event memory signal which portrays the state of the event memory. The setting signal for an event memory becomes active when activation of an event signal associated with this event memory is detected. The event memory signals are connected to an interrupt signal for the microprocessor. The microprocessor has read and write access to the event memory signals via a data bus. The event memories each have an input for a resetting signal. The resetting signal in a group becomes active when the microprocessor effects write access to the group containing this event memory using a first write signal and, at the same time, that individual signal from the microprocessor which is associated with this event memory is active on the data bus.

Abstract: The present invention relates to the data synchronization between a data processing system 3 and a servo-system 1 for an apparatus for reading from and/or writing to optical recording media. It is an object of the present invention to provide an improved method for synchronizing the subcode time codes and sector addresses of data contained on a recording medium. According to the invention, the method comprises the steps of: sending 4 a number of sectors from the micro controller 1 to the data processing system 3; requesting 8 information about the sector headers of the received sectors from the data processing system 3; calculating 9 the difference between the subcode time codes and the sector addresses using the information about the sector headers; repeating the synchronisation steps 4, 8, 9 for every session on the recording medium.

Abstract: An interrupt controller for a microprocessor (30) having a plurality of event memories (40, 41) which are combined to form at least one group and each have an input for a setting signal (5) and an output for an event memory signal (4) which portrays the state of the event memory (40, 41),—where the setting signal (5) for an event memory (40, 41) becomes active when activation of an event signal (8) associated with this event memory (40, 41) is detected,—where the event memory signals (4) are connected to an interrupt signal (9) for the microprocessor (30),—where the microprocessor (30) has read and write access to the event memory signals (4) via a data bus (10), and—where the event memories (40, 41) each have an input for a resetting signal (3), is designed such that the event memories can be specifically altered individually or else in groups without events being unintentionally lost in the process, which means that they cannot be processed.

Abstract: The invention relates to an apparatus for the reproduction or recording of data or information with a photodetector and digital error signal and evaluation signal processing. The object of the invention is to provide an apparatus for the reproduction or recording of data or information which requires little outlay despite digital evaluation signal processing and a considerable capability of adaptation to different scanning speeds. The invention is based on the principle of enabling digital evaluation signal generation with an analog-to-digital converter known from audio technology, even though the data rate of the data or high-frequency signal requires an analog-to-digital converter for the radio-frequency or for the video signal band. An analog-to-digital converter for the audio frequency band can be used to generate a digital evaluation signal by the analog-to-digital converter having fed to it not the high-frequency signal directly but rather at least one envelope of the high-frequency signal.

Abstract: The invention relates to a method and a circuit arrangement for a laser control loop with automatic adaptation to the monitoring signal polarity. Use is made of a single-phase method which consists in that a signal produced by the monitor during the starting phase of the laser control loop is compared with a reference value, and in accordance with the result of the comparison the signal produced by the monitor is fed directly or inverted to the comparator for controlling the light power of the laser during the starting phase of the laser control loop. A signal is produced which initially feeds the comparator for controlling the light power the inverted monitoring signal, or directly feeds the monitoring signal, in a fashion always independent of the monitoring signal polarity, but dependent on the polarity of a reference value, and feeds it in a non-inverted fashion in the case of a monitoring signal running up to the reference value.

Abstract: In a method of compensating for the tolerance errors in a digital-to-analog converter (D/A) the tolerance errors of the D/A are measured and individual correction factors are provided for each of the errors. The correction factors are stored and one of them is arithmetically combined with a portion of the digital number being converted to produce a combined signal. The combined signal is input into the digital-to-analog converter to produce an analog signal accurately representative of the digital signal.