Adaptive filtering method and apparatus to compensate for a frequency difference between two clock sources
US5859881A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1996 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Jun 7, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M9/00
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Frequency differences between differing clock sources are compensated for by an adaptive filtering mechanism. An amount of frequency drift between two clock sources is determined. Then, based on that amount of frequency drift, a filtering value is selected to be used in tracking the frequency drift. If the frequency drift is determined to be large, then a minimum filtering value is selected. However, if it is determined to be small, then a maximum filtering value is selected. The selected filtering value is used to adjust the address(es) of one or more data bits being transmitted and received using the two clock sources, such that the frequency drift is properly tracked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.