Servo-Tracking Faults - Certance LTO 1 User Manual

Theory
C2 ECC
C2 ECC involves three distinct operations:
1. Encoding: Generating C2 ECC bytes from data bytes (performed by ECC co-processor hard-
ware)
2. Decoding: Generating ECC syndromes from data and ECC bytes, testing for all-zeroes (per-
formed by ECC co-processor hardware)
3. Correction: Generating corrected data from syndromes.
The correction depends on the number and types of errors involved:
For one known C1 codeword pair in error in a sub-data set (C2 codeword), the operation is
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performed by the ECC co-processor hardware.
For two or more known C1 codeword pairs in error, the matrix is computed by firmware and
•
the correction is performed by hardware.
For one or more unknown C1 codeword pairs, syndromes are generated by hardware, error
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location is computed by firmware, the matrix is computed by firmware and the correction is
performed by hardware.

Servo-tracking Faults

During a write operation, if the servo system detects an error that may result in adjacent data tracks
being over-written, the write operation is aborted. The write operation will not continue until the cor-
rect servo tracking is re-established.
Data Integrity
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