Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Christopher Scott Dudley

Martin Aureliano Hassner

Shad Henry Thorstenson

Anthony Edwin Welter

Christopher Scott Taylor

Thomas James Despins

A method, apparatus and a data storage device are provided for implementing drive list mode for read and write transfers on a recordable surface of a storage device. Drive List mode provides a queue in a linked list to chain together multiple independent transfers on a single track. The multiple drive independent transfers include at least one of sequential transfers, near-sequential transfers, and random transfers on the single track. A drive list mode transfer of multiple independent transfers on the single track is enabled in one disk revolution, and requiring a single hardware setup for the drive list mode transfer.

Implementing drive list mode for reads and writes for hard disk drives

To perform error detection and correction on a data sector, syndromes are calculated and used to determine error values and error locations. Logarithmic calculations in Galois field need to be performed to determine the error locations using the syndromes. Finite field vectors are represented as 'complex' numbers of the form Az+B. An algorithm is performed using the field vectors represented as complex numbers to generate the error locations. The algorithm requires the use of logarithm calculations. The results of the logarithmic calculations are looked up in two (or more) log tables. The log tables store all the possible results of the logarithm calculations. The log tables store significantly less bits than prior art techniques, reducing the amount of storage space required by a factor of 171. Techniques for controlling accesses to the log tables in an efficient manner are also provided.

Techniques for performing Galois field logarithms for detecting error locations that require less storage space

Growing community of inventors

Oronoco, MN, United States of America

Christopher Scott Dudley