State machine and method for monitoring and controlling operating modes in a computer-controlled telephony instrument
US5848136A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1996 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Dec 20, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/6033
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
There is disclosed a telephone instrument having controller and audio unit portions coupled together by a control bus and a user data bus having four audio states. The audio unit portion comprises a state machine that allows operating modes of the telephony instrument to be monitored and controlled. The state machine places the user data bus in a first predetermined state and the controller portion responds by placing the control bus in a selected state. The state machine detects the selected state and, in response thereto, places the user data bus in a second predetermined state. The second predetermined state indicates whether the first predetermined state was intended to be one of the four audio states or one of at least two mode control states. The user data bus and the control bus cooperate to provide a sequential output having at least six states, thereby allowing the operating modes to be monitored and controlled without modifying the bus drive circuitry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.