Selective shadowing and paging in computer memory systems

Details Selective shadowing and paging in computer memory systems Selective shadowing and paging in computer memory systems

1994-11-18

1997-02-11

Chan, Eddie P.

395413, 395419, 395652, G06F 1210, G06F 1202, G06F 945

Patent

active

056030118

ABSTRACT:
Principal data (e.g. frequently accessed data such as video BIOS program information and a principal font set) and secondary data (e.g. secondary font sets) are permanently stored in a slow memory device (e.g. EPROM). To improve performance, the principal data but not the secondary data is copied initially to a faster access memory device (shadow RAM). Translating logic associated with the latter device is initially configured to intercept memory requests, having addresses in a range preassigned to the EPROM, and redirect them to shadow RAM. However, in order to allow for access to the secondary data, the redirection function of the translating logic can be disabled and re-enabled, under control of programs running in an associated computer, so that requests in the preassigned address range are routed directly to the EPROM. When the translating logic is disabled, all of the EPROM becomes accessible including locations containing the principal data and locations containing the secondary data. When the translating logic is enabled, only the principal data in the shadow RAM is accessible. The disabling and re-enabling functions are implemented presently by means of unique function calls issuable to system BIOS by operating system, device driver and application programs. In the disclosed embodiment, the size of the principal data is that of a page block, shadow RAM stores the principal data page and only that page, and the capacity of EPROM is sufficient to store the two or more page blocks of (principal and secondary) data.

REFERENCES:
patent: 4403283 (1983-09-01), Myntti et al.
patent: 4443847 (1984-04-01), Bradley et al.
patent: 4785398 (1988-11-01), Joyce et al.
patent: 4899275 (1990-02-01), Sachs et al.
patent: 5072411 (1991-12-01), Yamaki
patent: 5091850 (1992-02-01), Culley
patent: 5193170 (1993-03-01), Lam
patent: 5202994 (1993-04-01), Begur et al.
patent: 5210850 (1993-05-01), Kelly et al.

Affiliated with

Also associated with

Rating

Selective shadowing and paging in computer memory systems does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Selective shadowing and paging in computer memory systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Selective shadowing and paging in computer memory systems will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-350220