Buffering system bus for external-memory access
US6708257B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 12, 1999 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | Dec 10, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F13/1673
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A computer system includes a processor, a cache, a system bus, a memory-control subsystem, an external memory bus, RAM memory, and flash memory. All but the last three are fabricated on a single ASIC. The memory control subsystem includes a RAM controller, a flash-memory controller, and a memory interface between the controllers and the memories. In addition, the memory-control subsystem includes a system-bus FIFO write buffer. During an external-memory access, the request information is transferred from the system bus to the system-bus buffer instead of directly to the memory interface. The system-bus buffer stores address data, content data (in the case of a write request), and control data. In turn, the control data is forwarded to the appropriate controller and the address data and the content data are forwarded to external memory bus. Note that only one system-bus write buffer is required despite the plural memory controllers. While the processor write buffer frees the processor for other tasks while a write operation is being completed, the system-bus write buffer frees the system bus for other tasks while a write operation is being completed. The system-bus buffer thus allow…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.