Integrated cache memory system with primary and secondary cache memories
US5249282A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 1990 |
| Grant date | Sep 28, 1993 |
| Priority date | — |
| Expiry date | Nov 21, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0897
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A central processing unit (10) has a cache memory system (24) associated therewith for interfacing with a main memory system (23). The cache memory system (24) includes a primary cache (26) comprised of SRAMS and a secondary cache (28) comprised of DRAM. The primary cache (26) has a faster access than the secondary cache (28). When it is determined that the requested data is stored in the primary cache (26) it is transferred immediately to the central processing unit (10). When it is determined that the data resides only in the secondary cache (28), the data is accessed therefrom and routed to the central processing unit (10) and simultaneously stored in the primary cache (26). If a hit occurs in the primary cache (26), it is accessed and output to a local data bus (32). If only the secondary cache (28) indicates a hit, data is accessed from the appropriate one of the arrays (80)-(86) and transferred through the primary cache ( 26) via transfer circuits (96), (98), (100) and (102) to the data bus (32). Simultaneously therewith, the data is stored in an appropriate one of the arrays (88)-(94). When a hit does not occur in either the secondary cache (28) or the primary cache (26), da…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.