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US 7,126,775 B1Granted
Servo track address channel code for d=1 magnetic recording
AssigneeCirrus Logic, Inc.
InventorChristopher P. Zook
Life of this patent
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AssigneeCirrus Logic, Inc.
InventorChristopher P. Zook
Estimating the term…
A rate ½, d=1 channel code encodes a Gray code servo track address into channel data recorded on a magnetic disk; a d=1 Viterbi sequence detector detects the recorded servo track address upon read back; a cost effective d=1 decoder decodes the recorded servo track address into its Gray code representation; and a 1/1+D filter decodes the Gray code track address into its binary representation. The channel encoding scheme increases the data density of the storage system due to the d=1 constraint and use of the Viterbi sequence detector. Further, the implementation advantageously uses the Viterbi sequence detector already provided in a read channel for detecting user data, and the cost and complexity of the decoder is reduced by encoding/decoding the Gray code track address in sections of five bits.
Apparatus for decoding a recorded servo track address read from a magnetic storage disk, comprising:
A read channel in a magnetic disk drive storage device for detecting and decoding RLL (1,k) encoded user data and RLL (1,k) encoded servo data recorded on a magnetic disk using a magnetic read/write head positioned there above, wherein the encoded servo data comprises a plurality of servo track addresses corresponding to a plurality of data tracks recorded on the magnetic disk, the read channel comprising:
A method for decoding a servo track address recorded on a magnetic disk as an RLL (1,k) rate 1/2 codeword, comprising the steps of:
Dependencies are inferred from the claim text.