Phase discrimination and data separation method and apparatus

Abstract From the Canadian patent

Phase discrimination and data separation method and apparatus for on-track error recovery by shifting input data in time relative to a clock to improve recovery of error bits due to bit shift in a disk storage system having a servo clock synchronized to a disk's rotational speed and a reference clock which must be synchronized to the servo clock to insure that the data previously written onto the disk will be retrieved correctly during read back. Data encoded in (1,7) or denser codes can be recovered because of fewer transitions in a phase discriminator and therefore a shortened phase discrimination cycle in a feedback loop to avoid interference into the following correction. Readback data …