Apparatus for providing multiple controller interfaces to a standard digital modem and including integral conflict resolution
US5025500A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 9, 1989 |
| Grant date | Jun 18, 1991 |
| Priority date | — |
| Expiry date | Jun 9, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/44
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A communication system which includes a modem and a plurality of controllers has each controller connected to the modem by an interface apparatus, each controller and the modem complying with a predetermined protocol. The interface apparatus comprises a bus which provides a medium to transfer signals between the controllers and the modem. A first interface unit, which interfaces the modem to the bus, implements a modem-associated multi-state state machine and responds to signals on the bus maintaining the predetermined protocol between the modem and the first interface unit. A plurality of second interface units interface a corresponding controller to the bus. Each second interface unit implements a controller-associated multi-state state machine which responds to signals on the bus and further responds to signals from the corresponding controller, each second interface unit maintaining the predetermined protocol between the second interface unit and the corresponding controller. Further, each second interface unit transmits onto the bus in a predefined cycle to resolve conflicts between controllers for access to the bus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.