System for copying IOBS from FIFO into I/O adapter, writing data completed IOB, and invalidating completed IOB in FIFO for reuse of FIFO
US5905905A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1997 |
| Grant date | May 18, 1999 |
| Priority date | — |
| Expiry date | Aug 5, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/126
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A host computer having a CPU and a FIFO memory connected to an I/O adapter for the exchange of I/O information between the host and the adapter. The host writes I/O commands and stores them in a relatively small FIFO memory of the host. The I/O commands are then copied to a relatively large I/O memory array in the I/O adapter where they are stored until the I/O command is completed. The FIFO is then free for use by other I/O commands from the host CPU. I/O completion information is returned to a completion queue in the host by the adapter. This information includes completion status and an indication of the number of I/O commands copied to the adapter from the host FIFO. This allows the CPU to invalidate and reuse all FIFO locations containing I/O commands that have been copied from the FIFO to the adapter I/O array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.