System for an method of efficiently controlling memory accesses in a multiprocessor computer system
US5895496A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1997 |
| Grant date | Apr 20, 1999 |
| Priority date | — |
| Expiry date | Nov 18, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0817
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for controlling memory accesses in a memory device in a multi-processor computer system comprises a memory controller and a data storage. The data storage comprises a plurality of memory lines. Each memory line has a check field for storing a GONE code that indicates that the data is held in a cache, a g bit field for storing a G bit for confirming the code in the check field, a tag field for storing an identification of the processor in whose cache the data is held, and a d bit field for storing the true value of the G bit in rare situations. The memory controller comprises a data buffer, an address buffer, and a memory sequencer. The memory sequencer is a state machine for controlling the functions of the memory device. The method includes the steps of reading a memory line; determining if the data contained in a check field portion of the memory line matches a GONE code generated from the address of the memory line; if the check field and GONE code values do not match, reading the data as data; if the check field and GONE match, checking the G bit; if the G bit is 1, outputting the address of the processor that holds the data in its cache; and if the G bit is 0, reconst…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.