Patent · US Expired

Data tracking clock recovery system using digitally controlled oscillator

US4456890A · kind A · utility

33Cited by
6References
7Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 5, 1982
Grant dateJun 26, 1984
Priority date
Expiry dateApr 5, 2002

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L7/033
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A clock recovery system including a VCO responsive to a voltage signal for generating a clock signal. A phase detector includes a register and a PROM, the register counting the clock signal to derive the output clock signal. The PROM is responsive to input data and the count in the register to detect and store information concerning relative phase relationships. A counter contains a count from which the control voltage for the VCO is derived. The PROM is operable to alter the count in the counter, thereby performing frequency adjustments, and to alter the count in the register to perform phase adjustments. Also, a converter, operable by the phase detector, may also derive a voltage signal for damping purposes.

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