Patent · US Expired

Method and apparatus for indicating when each track is in burst in a multitrack tape device

US5357380A · kind A · utility

6Cited by
13References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 14, 1993
Grant dateOct 18, 1994
Priority date
Expiry dateJun 14, 2013

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B2220/90
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A method and apparatus which first calculates track to track skew in a tape device and then uses the results of that calculation to adjust the windows for detection of sync and resync characters. The system makes use of global circuitry which adjusts the sync and resync windows for all tracks based upon the skew calculation. In the case of the windows used for detecting resyncs, when skew is determined to be large, the global resync window must span a larger time period to account for the skew in detecting resync marks. Conversely, when there is little or no skew present, the windows for resync detection can be narrowed. Normally, the track logic utilizes its own local windows to detect resyncs. If a track misses a resync, however, it must use the global resync window to determined the next resync location. Once the tracks are resynchronized, control can return to local track circuitry to maintain synchronization. In the case of force windows used for detecting the syncs after a resync alignment burst, the skew calculation is used to determine the correct sync location for each particular track. Further, data alignment is maintained in the multitrack environment through the use of …

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.