System for transferring data between main computer multiport memory and external device in parallel system utilizing memory protection scheme and changing memory protection area
US5901328A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1997 |
| Grant date | May 4, 1999 |
| Priority date | — |
| Expiry date | Sep 24, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/1433
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A memory protection setting unit sets a protection area in a multiport memory provided with two ports, that is, port A and port B. The CPU accesses the multiport memory through port A. At this time, an area other than the protection area can be accessed. The CPU transmits data to an external device through a transfer control device. The transfer control device accesses the multiport memory through port B. Only the protection area can be accessed at this time. Upon receipt of a request from the CPU, the transfer control device writes data received from the external device to the protection area and reads data to be sent to the external device from the protection area. Protection is removed by the memory protection setting unit from the protection area where data is read or written by the transfer control device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.