Writing preliminary compensation optimization method and apparatus in PRML channel

摘要

Write preliminary compensation for a partial response maximum likelihood (" PRML ") magnetic recording channel suitable for a mass production environment is initiated. The optimal write precompensation includes writing a known tri-bit data pattern to create a non-linear transition shift (" NLTS ") under worst case conditions on the magnetic recording medium, reading the recorded data pattern, (" MSE ") for one or more smoothed data sample levels associated with the smoothed data sample level. The optimal amount of write preliminary compensation is determined by minimizing the MSE for the selected sample level, or by minimizing the MSE between the middle and upper or lower levels of the three PRML sample levels.