System and method for identifying expansion devices in a computer system
US5594873A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 8, 1994 |
| Grant date | Jan 14, 1997 |
| Priority date | — |
| Expiry date | Dec 8, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/4411
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for identifying option modules or expansion devices coupled to an expansion bus using time domain methods. According to the present invention, each expansion device includes logic circuitry that asserts an identification signal a preset time duration after a host reset signal is pulsed. A unique preset time duration or time constant is designated for each expansion device, and the host computer identifies each expansion device by the length or duration of the identification signal. In the preferred embodiment, during the power-on sequence the computer system asserts a reset signal pulse to the identification logic in each respective expansion device which directs the expansion device to assert its identifying signal. The host computer determines the length of time between assertion of the reset signal pulse and assertion of the identification signal and uses this information to determine the type of expansion device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.