METHOD AND DEVICE FOR MEASURING AND REGISTERING STATISTICAL TIME VARIATIONS FOR AN OPTICAL DATA CARRIER

摘要

A device (40) for measuring and registering statistical time variations in a measurement signal obtained when reading or playing an optical data carrier (34) has a controller (41) capable of receiving the measurement signal; storage means (49) with a plurality of addressable memory cells; means (47) for generating a ramp signal when receiving a start command from the controller (41); and means (48) for reading and digitalizing an instantaneous value of the ramp signal when receiving a read command from the controller (41). The controller detects a start event (A) in the measurement signal and gives a start command to the means (47) for generating a ramp signal. An end event (B) is detected in the measurement signal or in a reference or clock signal, wherein a read command is given to the means (48) fo reading and digitalizing. The controller receives a digital value of the measurement signal at the time of the end event. A memory address is generated as a function of the received value of the measurement signal, by means of which the numerical content is read at said address from the storage means (49). An arithmetic operation is performed with the read memory content as an operand, and then the result of the operation is written at said memory address.