Method for indicating a sector on a data medium and data medium suited to this method
AssigneeSTMicroelectronics S.r.l.
InventorPhilippe Graffouliere
Life of this patent
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Abstract
For indicating on a data medium (9) a sector referenced by a binary word (16) formed of a number M of first bytes each comprising a number L of bits, the method includes steps of etching onto the data medium locally at this sector a succession of M second bytes each corresponding to a first byte, each second byte being equal to a vector of N components, each with a value of +1 or −1, such that N=2L−1 and such that the scalar product of said vector with any other vector to which another second byte is equal, is at most equal to +1. The data medium (9) is, for example, an optical disk.
Claims16
Method for indicating on a data medium a sector referenced by a binary word consisting of a number M of first bytes each comprising a number L of bits, characterized in that it includes steps of etching onto the data medium, locally at this sector, a succession of M second bytes each corresponding to a first byte, each second byte being equal to a vector having N components, each with a value of +1 or −1, such that N=2L−1 and such that the scalar product of said vector with any other vector to which another second byte is equal, is at most equal to +1.
Method according to any one of the preceding claims, characterized in that a third byte, called a synchronization byte, is added at the head of the succession of M second bytes, said synchronization byte consisting of a maximum length binary sequence of P bits with P greater than N.
Method according to any one of the preceding claims, characterized in that the component values of each of 2L−1 first vectors result from a different circular permutation over the same first maximum length binary sequence of N values and in that the component values of each of 2L−1 other vectors are of opposite sign to the component values of a different one of the 2L−1 first vectors.
Data medium (45) comprising a plurality of sectors for recording computer data, characterized in that it includes, locally on each sector referenced by a binary word formed of a number M of first bytes each comprising a number L of bits, a succession of M second bytes each corresponding to a first byte, each second byte being equal to a vector of N components, each with a value of +1 or −1, such that N=2L−1 and such that the scalar product of said vector with any other vector to which another second byte is equal, is at most equal to +1.
Data medium according to any one of the preceding claims, characterized in that a third byte, called a synchronization byte, is located at the head of the succession of M second bytes, said synchronization byte consisting of a maximum length binary sequence of P bits with P greater than N.
Data medium according to any one of the preceding claims, characterized in that the component values of each of 2L−1 first vectors result from a different circular permutation over the same first maximum length binary sequence of N values and in that the component values of each of 2L−1 other vectors are of opposite sign to the component values of the different one of 2L−1 first vectors.
Integrated circuit (53) for detecting on a data medium (45) a recording sector referenced by a binary word (56), characterized in that this comprises:
- a correspondence table (7) that matches to a succession of M first bytes forming a binary word (56) each with a number L of bits a succession of M second bytes each corresponding to a first byte, each second byte being equal to a vector of N components, each with a value of +1 or −1, such that N=2L−1 and such that the scalar product of said vector with any other vector to which another second byte is equal, is at most equal to +1.
- a logic unit (57) constructed for forming the scalar product of a first vector of the correspondence table with a second vector originating from a signal (58) received at the input of the integrated circuit (53) and arranged to detect that the second vector matches a first byte when the scalar product of the first and second vector is substantially greater than +1.
Dependencies are inferred from the claim text.