Byte count handling in serial channel extender with buffering for data pre-fetch
US4866609A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1988 |
| Grant date | Sep 12, 1989 |
| Priority date | — |
| Expiry date | Sep 21, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/122
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A channel subsystem with a conventional serial extender link that causes communications between a channel and a control unit to be delayed by the additional time to transmit a message in one direction and to transmit an acknowledgement in the other direction. The channel subsystem also has a buffer and associated components (called a channel outboard box) that are used for prefetching data from processor memory or from a peripheral device without waiting for the acknowledgment routines that are commonly used on both an interlocked data transfer and a non-interlocked transfer (called data streaming). A system of counters and other components and associated operations maintain the correct byte count that would otherwise be maintained in a system without the prefetch buffer and with only a short serial link. A system of count and status frames provides for sending byte count and other status information between the channel and the outboard box.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.