Patent ID: 6496316
Filing Date: 2002-12-17
Classification: G11B

Abstract:
A data error rate measuring method comprising the steps of:setting a first equalization coefficient value of a wave form equalizer at a first value which results in a first output wave form of the wave form equalizer; carrying out first data read tests in accordance with the first output wave form; detecting errors in the first tests; counting a number of errors generated in the first tests; setting a second equalization coefficient value of the wave form equalizer at a second value which results in a second output wave form of the wave form equalizer; carrying out second data read tests in accordance with the second output wave form; detecting errors in the second tests; counting a number of errors generated in the second tests; and estimating an inherent data error rate from a relation between each equalization coefficient value and a number of errors associated therewith in each respective counting step; wherein the inherent data error rate is estimated by extending a first curve and a second curve; wherein said first curve is obtained by data errors generated in the first tests; and said second curve is obtained by data errors generated in the second tests.