Operating system independent support for mixed voltage devices
US5634132A · kind A · utility
Inventors
Key dates
| Filing date | Jun 23, 1995 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Jun 23, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/4081
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for providing operating system independent support for mixed voltage devices, particularly PC card controllers. In one aspect of the invention, a system management mode ("SMM") of the processor of a PC is used to detect the proper voltage of a PC card inserted in a PC card slot and then to set the voltage level of the PC card controller appropriately. In one embodiment, SMM is entered responsive to detection that the operating system is setting up the registers of the PC card controller by writes to a particular I/O address. In another embodiment, SMM is entered responsive to detection of insertion of a PC card into a PC card slot. In any event, because SMM is operating system independent, the mixed voltage capability of the PC card controller will be supported regardless of whether the operating system installed on the PC supports such functionality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.