Patent ID: 6032284
Filing Date: 2000-02-29
Classification: G11B,H03M,H04L

Abstract:
A sampled amplitude read channel for reading data from a sequence of discrete time sample values generated by sampling an analog read signal emanating from a read head positioned over a storage medium, comprising:(a) a sampling device for sampling the analog read signal to generate the sequence of discrete time sample values;(b) a detector for detecting the data from the discrete time sample values; and(c) an encoder/decoder for encoding/decoding the data according to a code constraint which allows runs of X consecutive storage medium transitions to occur only if started at a predetermined periodic data index k, wherein(i) X is an integer greater than one;(ii) the periodic data index k is defined over a predetermined number of data indices ask modulo N=Pwhere P is an integer constant and N is an integer greater than one; and(iii) the encoder/decoder encodes m bits of user data into n bits of codeword where the code rate m/n is greater than 3/4.