Method and apparatus for processing multiple servo channels in magnetic recording devices

    公开(公告)号:US10510367B1

    公开(公告)日:2019-12-17

    申请号:US16150356

    申请日:2018-10-03

    IPC分类号: G11B5/55 G11B5/596 G11B5/60

    摘要: A method of operating a storage device includes reading data from a storage medium using a detector, processing signals from the detector through a plurality of processing circuits, each respective processing circuit in the plurality of processing circuits being optimized for a different state of a channel condition and providing a respective output metric, selecting a processing circuit from the plurality of processing circuits by comparing the respective output metrics from each processing circuit in a predetermined manner, and designating as output of the detector output of the processing circuit that is selected. The output metrics may be branch metrics or path metrics, and the channel condition may be fly-height or phase shift. The storage device includes a storage medium, and a read channel including a detector, and processing circuits that process signals from the detector. Each respective processing circuit is optimized for a different state of a channel condition.

    System and method for compensating for radial incoherence associated with reading servo sectors

    公开(公告)号:US10170142B1

    公开(公告)日:2019-01-01

    申请号:US15708668

    申请日:2017-09-19

    IPC分类号: G11B5/035 G11B5/596 G11B20/10

    摘要: A system for compensating RI while reading servo data from a rotating storage medium is provided and includes an equalizer, a Viterbi detector, and a servo control module. The equalizer receives a digital signal including a bit sequence of the servo data read from the rotating storage medium and equalizes the digital signal via filters. Some of the filters are to phase rotate the digital signal to generate phase rotated signals. The Viterbi detector operates based on a Viterbi state machine, which includes main branches having sub-branches, where: each of the main branches is to receive the phase rotated signals respectively at corresponding ones of the sub-branches; and the Viterbi detector is to determine branch metrics for each of the sub-branches, determine a minimum branch metric for each of the main branches, and process the minimum branch metric using an add-compare-select process to determine a most likely received bit sequence.