Patent · US Expired

Apparatus guaranteeing that a controller in a disk drive system receives at least some data from an invalid track sector

US4825403A · kind A · utility

138Cited by
13References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 29, 1986
Grant dateApr 25, 1989
Priority date
Expiry dateApr 29, 2006

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B2220/20
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An apparatus provides a sequence detected signal indicating that a synchronization sequence occurring at regular intervals in a stream of data has occurred or should have occurred. The apparatus includes logic for detecting the synchronization sequence, logic responsive to the detection logic for producing the sequence detected signal when the detection logic detects the sequence, and logic for producing the sequence detected signal at a fixed time after the synchronization sequence should have occurred. If the synchronization sequence did occur, the apparatus thus produces two sequence detected signals; however, the device receiving the sequence detected signal responds to the first sequence detected signal and ignores the second. If the synchronization sequence did not occur, the device receiving the sequence detected signal responds to the sequence detected signal produced by the logic responsive to the timing apparatus. The apparatus thus guarantees that the device receiving the sequence detected signal will always receive such a signal.

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