Disk storage system employing error detection and correction of channel coded data, interpolated timing recovery, and retroactive/split-segment symbol synchronization

A method for recording data onto and reading data from a disk medium, comprising the steps of:

• (a) encoding user data, received from a host system, according to a first channel code to generate coded user data;
• (b) encoding the coded user data to generate redundancy symbols;
• (c) encoding the redundancy symbols according to a second channel code to generate coded redundancy symbols;
• (d) writing the coded user data and the coded redundancy symbols to the disk medium;
• (e) detecting estimated coded user data from discrete-time sample values generated by sampling an analog read signal emanating from a read head positioned over the disk medium;
• (f) storing the estimated coded user data in a data buffer;
• (g) detecting estimated coded redundancy symbols from discrete-time sample values generated by sampling an analog read signal emanating from a read head positioned over the disk medium;
• (h) decoding the estimated coded redundancy symbols into estimated redundancy symbols;
• (i) generating error syndromes using the estimated coded user data and the estimated redundancy symbols;
• (j) reading the coded user data from the data buffer and, using the error syndromes, detecting and correcting errors in the estimated coded user data to generate corrected coded user data;
• and
• (k) decoding the corrected coded user data into corrected user data transferred to the host system.

A disk storage device for reading data from a disk medium, comprising:

• (a) a sampling device for sampling an analog read signal from a recording head positioned over the disk medium to generate a sequence of discrete-time sample values;
• (b) a samples buffer connected to receive a plurality of the discrete-time sample values;
• (c) discrete-time timing recovery for extracting timing information from the discrete-time sample values;
• (d) a discrete-time sequence detector for detecting a binary sequence from the discrete-time sample values;
• and
• (e) a controller for iteratively transferring the plurality of discrete-time sample values stored in the samples buffer to the discrete-time sequence detector and setting a programmable parameter to a different value until a bit error rate of the sequence detector is below a predetermined level.

A method for reading data from a disk medium, comprising:

• (a) sampling an analog read signal from a recording head positioned over the disk medium to generate a sequence of discrete-time sample values;
• (b) storing a plurality of the discrete-time sample values in a samples buffer;
• (c) extracting timing information from the discrete-time sample values;
• (d) detecting a binary sequence from the discrete-time sample values;
• (e) iteratively transferring the plurality of discrete-time sample values stored in the samples buffer to the discrete-time sequence detector and setting a programmable parameter to a different value until the bit error rate of the sequence detector is below a predetermined level.