Electronic device for calculating the time interval between successive transitions of an incident signal

A digital disk reader comprising an electronic device for calculating a time interval between two selected successive transitions of a sampled incident signal with respect to a threshold, the electronic device comprising:

• a detection and selection circuit for detecting and selecting transitions of the sampled incident signal;
• a calculating circuit for calculating a time gap between each selected transition and an edge of a sampling clock signal;
• a unit comprising at least three blocks, each block comprising a storage cell and a counter responsive to the sampling clock signal;
• and
• a processor for
• triggering an activation processing by said unit responsive to each current selected transition by initializing said counter of said first block, storing in said storage cell of said first block the time gap corresponding to the current selected transition, and transferring a time gap previously stored in said storage cell of said first block to said storage cell of said second block and transferring a time gap previously stored in said storage cell of said second block to said storage cell of said third block, and
• determining the time interval between two successive selected transitions based upon a value of each counter of said second and third blocks and the time gaps respectively stored in said storage cells of the second and third blocks.

A method for calculating a time interval between two selected successive transitions of a sampled incident signal with respect to a threshold and comprising:

• detecting and selecting transitions of the sampled incident signal;
• calculating a time gap between each selected transition and an edge of a sampling clock signal;
• triggering an activation processing by a first unit responsive to each current selected transition, the first unit comprising first, second, and third blocks each comprising a counter and a storage cell, the activation processing comprising
• initializing the counter of the first block;
• storing the time gap corresponding to the current selected transition in the storage cell of the first block;
• transferring a time gap previously stored in the storage cell of the first block to the storage cell of the second block and transferring a time gap previously stored in the storage cell of the second block to the storage cell of the third block;
• and
• determining the time interval between two successive selected transitions based upon a value of the counter of the second and third blocks and the time gaps respectively stored in the storage cells of the second and third blocks.