Enhanced dram with embedded registers
Abstract
An enhanced DRAM contains embedded row registers (56) in the form of SRAM cells (142, 144). The row registers (56) are adjacent to the DRAM array (40), and when the DRAM comprises a group of subarrays, the row registers (56) are located between DRAM subarrays (40). When used on-chip DRAM cache (48), these registers (56) hold frequently accessed data. This data corresponds to data stored in the DRAM (34) at a particular address. When an address is supplied to the DRAM (34), it is compared to the address of the data stored in the cache (56). If the addresses are the same, then the cache data is read at SRAM speeds. The DRAM (34) is decoupled from this read. The DRAM (34) also remains idle during this cache read unless the system opts to precharge or refresh the DRAM (34). Refresh or precharge occur concurrently with the cache read. If the addresses are not the same, then the DRAM (34) is accessed and the embedded register (56) is reloaded with the data at that new DRAM address. Asynchronous operation of the DRAM (34) is achieved by decoupling the row registers from the DRAM array (40), thus allowing the DRAM cells to be precharged or refreshed during a read of the row register (56).

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Projected expiry passed 14 January 2013, 13.7 years ago.
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1 sheet
Sheet 1
Every citation, both ways
| Document | Relation | Office | Category | Cited during | Relevant claims |
|---|---|---|---|---|---|
| EP0385389A2 | Cites | European Patent Office (EPO) | A | Search report | 11,15 |
| DE4100670A1 | Cites | Germany | X | Search report | 1,2,4,6,9,12,13,18,20,21 |
| DE4110173A1 | Cites | Germany | A | Search report | 14,22 |
| US4608666A | Cites | United States of America | X | Search report | 1,4-10,12,13 |
| US4943944A | Cites | United States of America | A | Search report | 1,4,6,8,9,12 |
| US5025421A | Cites | United States of America | A | Search report | 1,4,6,9,11-13 |
5 priority claims, no other members on record
Priority claims5
| Document | Office | Kind | Date |
|---|---|---|---|
| 824211 | United States of America | – | |
| 82421192 | United States of America | A | |
| 93100465 | European Patent Office (EPO) | A | |
| EP19930100465 | – | – | – |
| US19920824211 | – | – | – |
8 legal events, as the office reported them to INPADOC
Over the term
Point at a mark for the eventEvents
| Event | Code | |
|---|---|---|
| Information on the status of an ep patent application or granted ep patentGrantedSTATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWNSTAA | STAA | |
| Application deemed to be withdrawnWithdrawn18D | 18D | |
| Designated contracting statesAK | AK | |
| Information provided on ipc code assigned before grant6G 06F 12/08 A, 6G 11C 11/00 BRIC1 | RIC1 | |
| Search report despatchedORIGINAL CODE: 0009013PUAL | PUAL | |
| Divisional application: reference to earlier applicationAC | AC | |
| Designated contracting statesAK | AK | |
| Public reference made under article 153(3) epc to a published international application that has entered the european phaseORIGINAL CODE: 0009012PUAI | PUAI |
Numbers
- Publication
- 0895162
- Publication, DOCDB
- 0895162
- Publication, EPODOC
- EP0895162
- Application
- 98120219
- Application, DOCDB
- 98120219
- Application, EPODOC
- EP19980120219
Titles3
- German
- Verbesserte DRAM mit eingebauten Registern
- English
- Enhanced dram with embedded registers
- French
- Dram amélioré avec régistres intégrés
Classification
- CPC, 10
- G11C7/106
- G06F12/0893
- G11C7/1006
- G11C7/1051
- G11C7/1078
- G11C7/1087
- G11C11/005
- G11C11/406
- G11C11/4096
- Y02D10/00
- IPC, 7
- G06F12 08
- G11C7 10
- G11C11 00
- G11C11 401
- G11C11 406
- G11C11 4096
- G11C11 41
Designated states5
- Contracting states, 5
- Germany
- France
- United Kingdom
- Italy
- Netherlands (Kingdom of the)