EP0544252A2
Expired / Lapsed
EP
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Data management system for programming-limited type semiconductor memory and IC memory card having the data management system
Assignee: Fujitsu Ltd
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Filing: 1992-11-25
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Granted: —
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Expires: 2012-11-25
Abstract
Abstract In a data management system for a programming-limited type semiconductor memory (M) which is programmable a limited number of times and which includes a plurality of storage areas, a management unit (1) manages, for each of the storage areas, the number of times that programming has been performed. A control unit (2) selects one of the storage areas for which programming has been performed the smallest number of times and has input data is written into the selected one of the storage areas, so that all the storage areas can be equally programmed.
Inventors
- 👤 Noriyuki c/o Fujitsu Limited Matsui
- 👤 Hiroyuki c/o Fujitsu Limited Itoh
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 23:28
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G06F3/0668; G06F3/0671; G06F3/0683; G06F3/0688; G06F3/0602; G06F3/0614; G06F3/0616; G06F3/0628; G06F3/0629; G06F3/0646; G06F3/0647; G06F3/0653; G06F3/0673; G06F3/0679; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C16/10; G11C16/102; G11C16/34; G11C16/349; G11C16/3495; G06F3/0662; G06F3/0664
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
106 words
A data management system for a programming-limited type semiconductor memory (M) which is programmable a limited number of times and which includes a plurality of storage areas, characterized in that the data management system comprises: management means (1) for managing, for each of the storage areas, the number of times that programming has been performed; and control means (2), coupled to said management means for selecting one of the storage areas for which programming has been performed the smallest number of times and for having input data written into a selected one of the storage areas, so that all the storage areas can be equally programmed.
Claim 2
Dependent Claim
70 words
The data management system as claimed in claim 1, characterized in that said control means comprises first means, coupled to said management means, for calculating a difference between the largest number of times that programming has been carried out and the smallest number of times that programming has been carried out and for selecting a different one of the storage areas when the difference is greater than a threshold value.
Claim 3
Dependent Claim
64 words
The data management system as claimed in claim 1, characterized in that said control means comprises first means for saving data stored in the selected one of the storage areas into another one of the storage areas and for erasing the data from the selected one of the storage areas before the input data is written into the selected one of the storage areas.
Claim 4
Dependent Claim
40 words
The data management system as claimed in claim 3, characterized in that said control means comprises second means for saving only valid data stored in the selected one of the storage areas into said another one of the storage areas.
Claim 5
Dependent Claim
74 words
The data management system as claimed in claim 2, characterized in that said control means comprises second means for saving data stored in the selected one of the storage areas into one of the storage areas for which programming has been performed the largest number of times and for erasing the data from the selected one of the storage areas before the input data is written into the selected one of the storage areas.
Claim 6
Dependent Claim
50 words
The data management system as claimed in claim 5, characterized in that said control means comprises third means for saving only valid data stored in the selected one of the storage areas into said one of the storage areas for which programming has been performed the largest number of times.
Claim 7
Dependent Claim
22 words
The data management system as claimed in claim 1, characterized in that the storage areas are provided by respective semiconductor memory chips.
Claim 8
Dependent Claim
34 words
The data management system as claimed in claim 1, characterized in that the storage areas correspond to a plurality of blocks obtained by dividing an entire storage area of a single semiconductor memory chip.
Claim 9
Dependent Claim
109 words
The data management system as claimed in claim 1, characterized in that said control means comprises: first means for assigning a flag to each piece of erasable data; second means, coupled to said first means, for selecting one of the storage areas which has the largest number of flags respectively assigned to pieces of erasable data; third means, coupled to said first and second means, for saving valid data stored in the selected one of the storage areas into another one of the storage areas; and fourth means, coupled to said first and third means, for erasing the erasable data from the selected one of the storage areas once.
Claim 10
Dependent Claim
107 words
An IC memory card including a programming-limited type semiconductor memory (M) which is programmable by a limited number of times and which includes a plurality of storage areas, characterized in that the IC memory card comprises: management means (21) for managing, for each of the storage areas, the number of times that programming has been performed; and control means (22), coupled to said management means for selecting one of the storage areas for which programming has been performed the smallest number of times and for having input data written into a selected one of the storage areas, so that all the storage areas can be equally programmed.
Claim 11
Dependent Claim
70 words
The IC memory card as claimed in claim 10, characterized in that said control means comprises first means, coupled to said management means, for calculating a difference between the largest number of times that programming has been carried out and the smallest number of times that programming has been carried out and for selecting a different one of the storage areas when the difference is greater than a threshold value.
Claim 12
Dependent Claim
64 words
The IC memory card as claimed in claim 10, characterized in that said control means comprises first means for saving data stored in the selected one of the storage areas into another one of the storage areas and for erasing the data from the selected one of the storage areas before the input data is written into the selected one of the storage areas.
Claim 13
Dependent Claim
40 words
The IC memory card as claimed in claim 12, characterized in that said control means comprises second means for saving only valid data stored in the selected one of the storage areas into said another one of the storage areas.
Claim 14
Dependent Claim
74 words
The IC memory card as claimed in claim 11, characterized in that said control means comprises second means for saving data stored in the selected one of the storage areas into one of the storage areas for which programming has been performed the largest number of times and for erasing the data from the selected one of the storage areas before the input data is written into the selected one of the storage areas.
Claim 15
Dependent Claim
50 words
The IC memory card as claimed in claim 14, characterized in that said control means comprises third means for saving only valid data stored in the selected one of the storage areas into said one of the storage areas for which programming has been performed the largest number of times.
Claim 16
Dependent Claim
22 words
The IC memory card as claimed in claim 10, characterized in that the storage areas are provided by respective semiconductor memory chips.
Claim 17
Dependent Claim
34 words
The IC memory card as claimed in claim 10, characterized in that the storage areas correspond to a plurality of blocks obtained by dividing an entire storage area of a single semiconductor memory chip.
Claim 18
Dependent Claim
109 words
The IC memory card as claimed in claim 10, characterized in that said control means comprises: first means for assigning a flag to each piece of erasable data; second means, coupled to said first means, for selecting one of the storage areas which has the largest number of flags respectively assigned to pieces of erasable data; third means, coupled to said first and second means, for saving valid data stored in the selected one of the storage areas into another one of the storage areas; and fourth means, coupled to said first and third means, for erasing the erasable data from the selected one of the storage areas once.
References Cited (Backward Citations)
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