US3800295A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Asynchronously operated memory system
Assignee: International Business Machines Corp
•
Filing: 1971-12-30
•
Granted: 1974-03-26
•
Expires: 1991-12-30
Abstract
Abstract A memory system includes a plurality of dynamic storage memories, each controlled by its own independent refreshing means, and a processor capable of interacting with a selected memory when access to the selected memory through the processor is desired. This system allows the refresh interval for each memory to be adjusted independent of the system to the extent of the extrinsic capability of its individual characteristics.
Inventors
- 👤 R Anderson
- 👤 G Hasler
- 👤 R Kirby
- 👤 K White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:52
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/18; G11C19/182; G11C19/188; G06; G06F; G06F13/00; G06F13/38; G06F13/42; G06F13/4204; G06F13/4234; G06F13/4243; G11C11/00; G11C11/21; G11C11/34; G11C11/40; G11C11/401; G11C11/406; G11C19/28; G11C19/287
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
103 words
An asynchronous memory system comprising: A. a plurality of memory units of a given type having timing characteristics that vary from one to another of the units, B. independent memory unit timing means controlling each memory unit, the timing characteristic of each of said timing means being determined by a timing characteristic of the particular memory unit being controlled by it, C. a common interface, interacting selectively at different times with one of said memory units, to which said memory units are connected, and D. means responsive to said timing means for determining availability of a particular memory unit to said common interface.
Claim 2
Dependent Claim
103 words
An asynchronous memory system comprising: A. a plurality of memory units of a given type having timing characteristics that vary from one to another of the units, B. independent memory unit timing means controlling each memory unit, the timing characteristic of each of said timing means being determined by a timing characteristic of the particular memory unit being controlled by it, C. a common interface, interacting selectively at different times with one of said memory units, to which said memory units are connected, and D. means responsive to said timing means for determining availability of a particular memory unit to said common interface.
Claim 3
Dependent Claim
28 words
The system of claim 1 wherein said memory units are dynamic storage memories and at least one of the timing characteristics of said memories is their refresh interval.
Claim 4
Dependent Claim
41 words
The system of claim 2 in which said memories are random access memories and said means for determining availability of a particular memory unit indicates to said common interface the refresh status of said particular memory unit when access is desired.
Claim 5
Dependent Claim
38 words
The system of claim 2 in which said memories are recirculating storage shift register memories and said means for determining availability of a particular memory unit determines where within the recirculating storage information to be accessed is located.
Claim 6
Dependent Claim
22 words
The system of claim 1 wherein said common interface is a central processing unit of a data processing machine containing said memories.
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) | 1977-03-25 | 1977-09-24 | 1978-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-25 | 1981-09-24 | 1982-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-25 | 1985-09-24 | 1986-03-26 | $7700.00 | Window Closed / Lapsed |