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US5598370A
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Nonvolatile memory with cluster-erase flash capability and solid state file apparatus using the same
Assignee: International Business Machines Corp
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Filing: 1995-04-26
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Granted: 1997-01-28
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Expires: 2015-04-26
Abstract
Abstract A nonvolatile memory-with cluster-erase flash capability. A cluster information sector is included in each of N clusters, the cluster information sector of each cluster being written with the sequence number assigned to the cluster so that no two clusters have the same sequence number. When erasing a given sector, a controller saves its sequence number prior to erasure. Then, when initializing a given erased sector, the controller sets its sequence number to a value greater than the current maximum sequence number. The controller writes user data to sectors other than the cluster information sector for the cluster thus initialized according to their address sequence. Accordingly, an invalid sector can be distinguished from a valid sector without using an overwrite approach.
Inventors
- 👤 Hideto Niijima
- 👤 Hideo Asano
- 👤 Yoshinori Sakaue
- 👤 Takashi Toyooka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:10
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G06F12/00; G06F12/02; G06F12/0223; G06F12/023; G06F12/0238; G06F12/0246; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C16/10; G11C16/102; G06F2212/00; G06F2212/72; G06F2212/7209; G06F3/0628; G06F3/0662; G06F3/0664
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
75 words
A nonvolatile memory for cluster-erase flash, comprising: a flash memory having N clusters each having M sectors, wherein M and N are integers greater than one; each of said N clusters includes a cluster information sector, wherein one of said M sectors is said cluster information sector; and said cluster information sector of each of said N clusters holds a sequence number, wherein no two of said cluster information sectors have the same sequence number.
Claim 2
Dependent Claim
75 words
A nonvolatile memory for cluster-erase flash, comprising: a flash memory having N clusters each having M sectors, wherein M and N are integers greater than one; each of said N clusters includes a cluster information sector, wherein one of said M sectors is said cluster information sector; and said cluster information sector of each of said N clusters holds a sequence number, wherein no two of said cluster information sectors have the same sequence number.
Claim 3
Dependent Claim
41 words
The nonvolatile memory as claimed in claim 1, wherein said cluster information sector of each of said N clusters holds a cluster erase count, the sum of the cluster erase counts being equal to a maximum value of the sequence numbers.
Claim 4
Independent Claim
127 words
A method for storing data within a nonvolatile memory for cluster-erase flash, wherein the nonvolatile memory comprises a flash memory having N clusters each having M sectors, wherein M and N are integers greater than one and each of said N clusters includes a cluster information sector, wherein one of said M sectors is said cluster information sector, wherein said cluster information sector of each of said N clusters holds a sequence number, wherein no two of said cluster information sectors have the same sequence number and there being a maximum sequence number, and comprising the steps of: selecting a cluster to be written based on a cluster erase count contained in the cluster information sector; and writing data sequentially to the sectors within the selected cluster.
Claim 5
Independent Claim
127 words
A method for storing data within a nonvolatile memory for cluster-erase flash, wherein the nonvolatile memory comprises a flash memory having N clusters each having M sectors, wherein M and N are integers greater than one and each of said N clusters includes a cluster information sector, wherein one of said M sectors is said cluster information sector, wherein said cluster information sector of each of said N clusters holds a sequence number, wherein no two of said cluster information sectors have the same sequence number and there being a maximum sequence number, and comprising the steps of: selecting a cluster to be written based on a cluster erase count contained in the cluster information sector; and writing data sequentially to the sectors within the selected cluster.
Claim 6
Dependent Claim
22 words
The method of claim 3 wherein the sum of said erase counts for all said N clusters equals said maximum sequence number.
Claim 7
Dependent Claim
14 words
The method of claim 3 wherein said flash memory is a NAND-type flash EEPROM.
Claim 8
Dependent Claim
42 words
The nonvolatile memory of claim 1 wherein each of said cluster information sectors further comprises: a cluster erase count; and an attribute flag within said each cluster information sector for identifying each of said cluster information sectors as a cluster information sector.
Claim 9
Dependent Claim
98 words
A nonvolatile NAND-type flash EEPROM memory for cluster-erase flash, comprising: a flash memory having N clusters, each cluster having M sectors, wherein M and N are integers greater than one and wherein at least one of said M sectors is a data sector; each of said N clusters includes a cluster information sector wherein one of said M sectors is the cluster information sector; said cluster information sector of each of said N clusters holds a sequence number, wherein no two of the cluster information sectors have the same sequence number and there being a maximum sequence number.
Claim 10
Dependent Claim
98 words
A nonvolatile NAND-type flash EEPROM memory for cluster-erase flash, comprising: a flash memory having N clusters, each cluster having M sectors, wherein M and N are integers greater than one and wherein at least one of said M sectors is a data sector; each of said N clusters includes a cluster information sector wherein one of said M sectors is the cluster information sector; said cluster information sector of each of said N clusters holds a sequence number, wherein no two of the cluster information sectors have the same sequence number and there being a maximum sequence number.
Claim 11
Dependent Claim
21 words
The nonvolatile memory of claim 7 wherein the sum of the cluster erase counts is equal to said maximum sequence number.
Claim 12
Dependent Claim
26 words
The nonvolatile memory of claim 7 wherein each of said data sectors further comprises an attribute flag which identifies said data sector as a data sector.
Claim 13
Dependent Claim
15 words
The nonvolatile memory of claim 1 wherein the nonvolatile memory comprises a NAND-type flash EEPROM.
References Cited (Backward Citations)
US5065364A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-28 | 2000-07-29 | 2001-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-28 | 2004-07-29 | 2005-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-28 | 2008-07-29 | 2009-01-28 | $7700.00 | Window Closed / Lapsed |