Variable rate clock for timing recovery and method therefor
US5875218A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 1995 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Mar 31, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0331
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Apparatus and method are provided that can be advantageously included in a timing phase-locked loop for finally adjusting the period of a timing signal being controlled by that loop. The loop filter receives the timing signal and generates a loop error signal indicative of whether the period of the timing signal should be held the same, increased or decreased. A strobe signal is also generated each time that the timing signal is to be so corrected. The error signal and strobe signal are provided to a function generator such as a state machine. Each time that the function generator is strobed by the strobe signal, it produces a count signal whose value is representative of N, N+C or N-C, where N and C are integers and C represents a preset desired increment of change for the timing signal per strobe, i.e. the fineness of the adjustment of the timing signal. When not strobed by the strobe signal, the state machine produces a count signal of value N. When the state machine is strobed by the strobe signal and the error signal indicates that the timing signal should be held as is, the state machine remains in a first state such that the count signal has a value of N. If the state machin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.