US4933910A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving the page hit ratio of a page mode main memory system
Assignee: NEC Corp
•
Filing: 1988-07-06
•
Granted: 1990-06-12
•
Expires: 2008-07-06
Abstract
Abstract Page mode memory access is enabled despite an immediately previous idle cycle. A row address strobe signal is maintained active during an idle cycle so that if a page hit is detected on a subsequent memory cycle, all that is needed to read or write to memory is a column address strobe signal which can be provided via a page mode access. In this manner, memory speed is enhanced because a conventional access is not required on the first memory cycle following one or more idle cycles.
Inventors
- 👤 Anthony M. Olson
- 👤 Babu Rajaram
- 👤 Thomas N. Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 23:21
CPC Classifications
G; G11; G11C; G11C7/00; G11C7/10; G11C7/1015; G11C7/1018; G11C7/1021
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
107 words
A page mode method for accessing a main memory array in a computer system in response to the initiation of a memory cycle comprising: strobing row address information into said memory array; strobing column address information into said memory array; waiting until a subsequent cycle begins; repeating said steps of strobing row address information, strobing column address information and waiting if said subsequent cycle is both not a page hit and not an idle cycle; repeating said steps of strobing column address information and waiting if said subsequent cycle is a page hit; and repeating said step of waiting if said subsequent cycle is an idle cycle.
Claim 2
Dependent Claim
107 words
A page mode method for accessing a main memory array in a computer system in response to the initiation of a memory cycle comprising: strobing row address information into said memory array; strobing column address information into said memory array; waiting until a subsequent cycle begins; repeating said steps of strobing row address information, strobing column address information and waiting if said subsequent cycle is both not a page hit and not an idle cycle; repeating said steps of strobing column address information and waiting if said subsequent cycle is a page hit; and repeating said step of waiting if said subsequent cycle is an idle cycle.
Claim 3
Dependent Claim
49 words
A page mode method for accessing a main memory array in a computer system in response to the initiation of a memory cycle, as recited in claim 1, wherein said step of repeating said step of waiting comprises maintaining a row address strobe signal active during said idle cycle.
Claim 4
Independent Claim
83 words
A method for performing a page mode memory access during a current access cycle immediately following an idle cycle in a computer system having a main memory array comprising: comparing row address information emitted by a central processing unit during said current access cycle with row address information emitted by said central processing unit during a most recent previous memory access cycle prior to said idle cycle; and accessing said memory array in a page mode fashion if said comparison yields a match.
Claim 5
Independent Claim
83 words
A method for performing a page mode memory access during a current access cycle immediately following an idle cycle in a computer system having a main memory array comprising: comparing row address information emitted by a central processing unit during said current access cycle with row address information emitted by said central processing unit during a most recent previous memory access cycle prior to said idle cycle; and accessing said memory array in a page mode fashion if said comparison yields a match.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-11 | 1993-12-11 | 1994-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-11 | 1997-12-11 | 1998-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-11 | 2001-12-11 | 2002-06-12 | $7700.00 | Window Closed / Lapsed |