A PRML and EPRML spliced operation scheme designed to reduce power dissipation of read channel chips

Abstract

In order to reduce the power dissipation and the circuit size for read channel chips, two techniques are proposed. One is based on the spliced operation of two different channel signaling methods such as F'RML and EPRML. These two detectors are operated selectively in correspondence with the value of the reliability information extracled from the data series. T h e other is an extended method which applies the transformed trellis simplification technique to a RADIX4 detector. These are effective for implementing a high tdata transfer rate. We have confirmed that the total detector power dissipation including PRML, EPRML and additional circuits is reduced to less than half of the conventional EPRML power dissipation, while achieving twice tha data transfer rate of the conventional EPRML.