Techniques for generating modulation codes using running substitutions
First Claim
1. A disk drive controller comprising:
- a modulation encoder that encodes data to generate encoded data; and
a substitution engine that performs substitutions of bit patterns within a sliding window of the encoded data that match at least one prohibited bit pattern.
3 Assignments
0 Petitions
Accused Products
Abstract
Techniques are provided for performing substitutions of bit sequences that are known to cause errors. Input data is initially modulation encoded. The modulated data is then analyzed in a sliding window to determine if it contains any additional bit sequences that are known to cause errors. If an error prone bit sequence is identified in the data, a substitution engine replaces the error prone bit sequence with a predetermined pattern of bits that is less likely to cause errors. The bit stream output of the substitution engine is then recorded on a storage medium. The recorded bit stream is decoded when it read from the medium. The decoding process identifies the substituted bit pattern and replaces the substituted pattern with the original sequence of bits.
-
Citations
20 Claims
-
1. A disk drive controller comprising:
-
a modulation encoder that encodes data to generate encoded data; and
a substitution engine that performs substitutions of bit patterns within a sliding window of the encoded data that match at least one prohibited bit pattern. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for performing modulation encoding on data prior to recording the data on a computer readable medium, the method comprising:
-
performing modulation encoding on the data to generate encoded data; and
substituting patterns of bits within a sliding window of the encoded data that match a prohibited bit pattern to generate substitute patterns. - View Dependent Claims (9, 10, 11)
-
-
12. A disk drive system comprising:
-
a modulation encoder that encodes data to generate encoded data constrained by a first global constraint; and
a substitution engine that identifies sequences of bits in the encoded data that violate an interleaved constraint, and replaces the sequences of bits that violate the interleaved constraint with bit patterns that satisfy the interleaved constraint. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
-
-
20. A method for performing modulation encoding on data prior to recording the data on a computer readable medium, the method comprising:
-
performing modulation encoding on the data to generate encoded data constrained by a first global constraint;
identifying sequences of bits in the encoded data that violate an interleaved constraint; and
substituting the sequences of bits that violate the interleaved constraint with bit patterns that satisfy the interleaved constraint and a second global constraint.
-
Specification