| 摘要 |
PROBLEM TO BE SOLVED: To determine whether a magnetic disk device is likely to fail based on the quality of a signal received from a head before a reading error actually occurs. SOLUTION: In a magnetic disk device 1, a register 6-1 holds in the read channel 6 the counts of correction during viterbi decoding carried out at every data reading at a read channel 6. Upon clearance of the counter value of the register 6-1 before reading test data, the magnetic disk device 1 reads test data written in a signal quality measuring area a predetermined number of times, and obtains each counter value which is obtained by counting correction of viterbi decoding from the register 6-1 after completing read of test data. Then, for example, a value obtained by converting the counts of correction during vibterbi decoding obtained in reading test data of 100 sectors into the amount equivalent to ten sectors, as a signal quality value, is calculated for each test data reading (e.g., ten times). COPYRIGHT: (C)2008,JPO&INPIT
|
