Interface device for modems
US4523322A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 23, 1982 |
| Grant date | Jun 11, 1985 |
| Priority date | — |
| Expiry date | Dec 23, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0993
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An interface device for synchronizing an internally clocked modem and data terminal equipment (DTE) provided with their own clock circuits, each of said own terminal clock circuit providing an external clock signal (RC Ext). The interface includes a PLO generating a recovered clock signal (XCO). At a moment defined by a request to send signal the phases of XCO and RC Ext are compared with each other and a switched clock signal SWC oscillating at a fast rate for a time interval corresponding to the phase delay between RC Ext and XCO and subsequently oscillating at a slow rate, is generated. The signal SWC is used for shifting RC Ext and terminal provided data RD Ext into shift registers respectively. The shifted RC Ext is used for controlling the adjustment of the interface PLO.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.