Method and apparatus for providing virtual DMA capability on an adapter connected to a computer system bus with no DMA support
US5668957A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1995 |
| Grant date | Sep 16, 1997 |
| Priority date | — |
| Expiry date | Nov 2, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/102
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Apparatus and method for providing virtual DMA capability for an adapter card connected to a host system bus with no DMA support. A special interface circuit resides on an adapter card together with a cache data memory. A special software driver resides in the host system. The software driver manages DMA transfers for the application processing circuitry on the adapter card using the cache data memory. The processing circuitry on the adapter card transfers data in and out of the cache data memory as if it had direct memory access to host system memory. In this way, an adapter card for a non-DMA-capable bus, such as the personal computer memory card international association (PCMCIA) bus can act as a bus master.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.