USB frequency synchronizing apparatus and method of synchronizing frequencies
US7940876B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 2008 |
| Grant date | May 10, 2011 |
| Priority date | — |
| Expiry date | Dec 1, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A universal series bus (USB) frequency synchronous apparatus using a start of frame (SOF) signal generated by a master device to mark a reference interval is disclosed. The frequency synchronizing apparatus includes a frequency divider, a counter unit with a default pulse number, an arithmetic unit, and an adjusting unit. The frequency divider divides a high frequency signal by a variable frequency factor to generate a lock frequency signal. The counter is used to detect a pulse number of the lock frequency signal at a reference interval and obtain a pulse difference between the default pulse number and the detected pulse number of the lock frequency signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.