USOO697097OB2
`
`(12) United States Patent
`Jung et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 6,970,970 B2
`Nov. 29, 2005
`
`(54) METHOD OF STORING DATA INA
`NON-VOLATILE MEMORY AND
`APPARATUS THEREFOR
`
`(*) Notice:
`
`KR
`(75) I
`I
`J
`Daei
`nventors: Ilm-young Jung, Daejeon
`Sung-ik Jun, Daejeon (KR); Kyo-il
`Chung, Daejeon (KR); Yong-sung
`Jeon, Daejeon (KR); Heon-young
`Yeom, Seoul (KR)
`(73) Assignee: Electronics and Telecommunications
`Research Institute, (KR)
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 289 days.
`(21) Appl. No.: 10/348,711
`(22) Filed:
`Jan. 22, 2003
`(65)
`Prior Publication Data
`US 2004/0064635 A1
`Apr. 1, 2004
`Foreign Application Priority Data
`(30)
`Oct. 1, 2002
`(KR) ...................... 10-2002-0059763
`(51) Int. Cl. ............................................... G06F 12/00
`(52) U.S. Cl. ........................ 711/103; 711/167; 707/202
`(58) Field of Search ................................ 707/100, 200,
`707/202; 711/103,167, 169
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`6,721,765 B2 * 4/2004 Ghosh et al. ............... 707/202
`6,732,124 B1* 5/2004 Koseki et al. .............. 707/202
`2002/0059275 A1
`5/2002 Schofield .................... 707/100
`2002/0184436 A1: 12/2002 Kim et al. .................. 711/103
`
`
`
`2003/0131023 A1*
`
`7/2003 Bassett et al. .............. 707/200
`
`FOREIGN PATENT DOCUMENTS
`
`JP
`JP
`
`2001-092713
`2001-147855
`
`4/2001
`5/2001
`
`OTHER PUBLICATIONS
`Jung, Im Y., et al., “A Transaction Implementation Method
`for Devices with Restricted Resources', The 12th Joint
`Conference in Communications and Information, Apr. 24,
`2002 (with English translation).
`Jung, Im Y., et al., “A Proposal to Implement Vew-Value
`Logging in Java Card Transaction”, The 6th World
`Multiconference on Systemics, Cybernetics and Informatics,
`Jul. 14, 2002, pp. 229-233.
`* cited by examiner
`Primary Examiner-Gary Portka
`ASSistant Examiner Jasmine Song
`(74) Attorney, Agent, or Firm-Blakely, Sokoloff, Taylor &
`Zafman
`
`(57)
`
`ABSTRACT
`
`Provided is a method of storing data in a non-volatile
`memory, including generating and Storing logs including
`data to be Stored and an address of the non-volatile memory
`in response to a data-writing request, and comparing
`addresses of the logs and Storing data corresponding to the
`Same page by the unit of page in a corresponding area of the
`non-volatile memory. The method makes it possible to
`minimize delay in Storing data, reduce the number of
`accesses to the non-volatile memory and uniformly write
`data in the whole non-volatile memory, thereby minimizing
`a response time of the non-volatile memory and increasing
`the lifetime of the non-volatile memory.
`
`13 Claims, 9 Drawing Sheets
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`PEERANSACON PROCESSN-56
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`SES NSE
`RSS 15
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`U.S. Patent
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`Nov. 29, 2005
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`Sheet 1 of 9
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`US 6,970,970 B2
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`U.S. Patent
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`Nov. 29, 2005
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`Sheet 2 of 9
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`US 6,970,970 B2
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`U.S. Patent
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`Nov. 29, 2005
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`Sheet 3 of 9
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`US 6,970,970 B2
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`FIG 3
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`RETURN TO NITA
`STATE PROR TO
`START OF
`TRANSACTION
`PROCESSING
`
`
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`
`
`BEGIN
`TRANSACTION()
`
`STAR OGGING
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`ABOR
`TRANSACTion())
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`100
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`POWER OFF
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`COMPLETE LOGGNG
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`COMMT
`TRANSACTION()} 110
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`U.S. Patent
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`Nov. 29, 2005
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`Sheet 4 of 9
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`US 6,970,970 B2
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`FIG. 4A
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`START
`
`
`
`BEGIN
`TRANSACTION()
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`SAR TRANSACON PROCESSNG
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`
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`SEN)
`RESPONSE
`TO BEGIN
`TRANSACTION()
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`SART LOGGENG TO RAM
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`OO
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`ABOR
`1RANSibnod YES
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`
`
`COMMT
`TRANSACTIONO
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`O
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`COMPLETION OF OGGING TO RAM - 153
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`TRANSFER OG N RAM TO
`TRANSACTION BUFFER OF EEPROM
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`WRE ATA N EEPROM
`BY THE UN OF OG
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`54.
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`55
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`COMPLETE TRANSACTION PROCESSENG)- 156
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`
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`SEN)
`RESPONSE
`O COMMIT
`TRANSACTION()
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`157
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`U.S. Patent
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`Nov. 29, 2005
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`Sheet 5 of 9
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`US 6,970,970 B2
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`FIG. 4B
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`SUPPY
`POWER AFTER
`NTERRUPTION
`OF POWER
`SUPPY
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`ANY
`TRANSACTION
`PROCESSNG
`N PROGRESS
`BEFORE
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`YES
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`WRTE DATA EN EEPROM
`BY THE UN OF LOG
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`161
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`SEN). A
`REPONSE TO
`ABOR
`TRANSACTIONC)
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`62
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`COMPLETE TRANSACTION
`PROCESSNC
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`156
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`U.S. Patent
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`Nov. 29, 2005
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`Sheet 6 of 9
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`US 6,970,970 B2
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`FIG. 5A
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`GSAR)
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`RECEIVE
`BEGIN
`TRANSACTION()
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`START TRANSACON PROCESSING
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`SENO
`RESPONSE
`TO BEGIN
`TRANSACTION()
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`SART OGGING O RAM
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`ABOR
`TRANSACTIONO?
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`OO
`YES
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`COMMT
`TRANSACTION()
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`11 O
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`COMPLETE OGGING TO RAM
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`123
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`TRANSFER LOG N RAM TO
`TRANSACTION BUFFER OF EEPROM
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`124
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`C
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`U.S. Patent
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`Nov. 29, 2005
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`Sheet 7 of 9
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`US 6,970,970 B2
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`FIG 5B
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`SENO
`RESPONSE
`TO COMM
`TRANSACTION()
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`25
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`RECEIVE DATA
`WRITING REQUEST?
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`WRFE DAA. IN EEPROM
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`130
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`WRTE DATA
`N THE SAME PAGE AS
`THE PAGE OF RAMSACTIO
`CG DATA
`
`YES
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`WRITE DATA IN EEPROM
`BY THE UN OF PAGE
`
`128
`
`29
`
`RANSACTION
`SUFFER
`EMPY?
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`
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`YES
`COMPLEE TRANSACTION
`PROCESSNC
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`31
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`U.S. Patent
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`Nov. 29, 2005
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`Sheet 8 of 9
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`US 6,970,970 B2
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`FIG. 5C
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`SUPPLY
`POWER AFFER
`INTERRUPTION
`OF POWER
`SUPPLY
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`TRANSACTION
`PROCESSNC N
`PROGRESS
`BEFORE2
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`SEND A
`REPONSE TO
`ABORT
`TRANSACTION()
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`42
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`44
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`S
`RANSACTION BUFFER
`OF EEPROM
`EMPTY?
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`YES
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`COMPLETETRANSACON
`PROCESSING
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`131
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`WRITE DAAN PAGE
`IN WHCHA) DRESS OF
`OG THAT IS NOT
`UPDATED IS INCLUDED
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`U.S. Patent
`U.S. Patent
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`Nov.29, 2005
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`Sheet 9 of 9
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`US 6,970,970 B2
`US 6,970,970 B2
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`J3AdNSBONN
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`O
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`s e
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`OL4
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`YVINONIO
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`3N3ND
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`SYALONALS
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`1
`METHOD OF STORING DATA IN A
`NON-VOLATILE MEMORY AND
`APPARATUS THEREFOR
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`The present invention relates to a method of Storing data
`and an apparatus therefor, and more particularly, to a method
`of and apparatus for Storing data in a non-volatile memory.
`2. Description of the Related Art
`An electrically erasable and programmable read only
`memory (EEPROM) as a non-volatile memory of a data
`Storage device, Such as a Smart card, can write and read data
`by a unit of page at a time. If data has to be written on two
`pages in the EEPROM, a delay of 3 through 10 ms occurs
`before data is written on the Second page. This time delay
`exists even when the data is written on the same page while
`a time gap exceeds 150 microSeconds. This time delay
`causes delay in the Smart card response time.
`In addition, the life span of the EEPROM is determined
`based on the number of writes on the EEPROM, and it may
`be shortened by one Spot where data is written more than a
`hundred thousand times. Therefore, it is desirable that data
`is written uniformly in the whole EEPROM.
`In the conventional art, there have been developed a
`logging method for transaction processing, a method of
`Synchronizing data in the Smart card with backup of the data
`outside the Smart card, and a method of reducing costs in
`transaction processing. However, implementations of the
`above methods have not been introduced yet. Moreover, the
`conventional art has problems in that delay appear when
`writing data in the EEPROM and the EEPROM has a short
`life span because data is written too frequently by the unit of
`log in the EEPROM.
`In addition, in the conventional art, any detailed approach
`for memory management has not been provided, and a spot
`of the EEPROM, Such as a transaction buffer, is too fre
`quently used and the life span of the Spot ends, and the
`EEPROM cannot be used any more although other spots can
`be used.
`
`SUMMARY OF THE INVENTION
`
`To solve the above-described and related problems, it is
`an object of the present invention to provide a method of
`Storing data in a non-volatile memory, the method which
`makes it possible to minimize delays in Storing data, reduce
`the number of accesses to the non-volatile memory, and
`uniformly write data in the whole non-volatile memory,
`thereby reducing a response time of the non-volatile
`memory and expanding the life span of the non-volatile
`memory, and an apparatus therefor.
`The present invention also provides a computer readable
`recording medium having embodied thereon a computer
`program for executing the method of Storing data in a
`non-volatile memory.
`In an aspect, the present invention provides a method of
`Storing data in a non-volatile memory, the method compris
`ing, in response to a data-Writing request, generating and
`Storing logs including data to be stored and an address of the
`non-volatile memory, and comparing addresses of the logs
`and Storing data corresponding to the same page by the unit
`of page in a corresponding area of the non-volatile memory.
`In another aspect, the present invention provides a data
`Storage device comprising a non-volatile memory, a log
`generating unit which generates and Stores logs having data
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`to be stored and addresses of the non-volatile memory in
`response to a data-Writing request, and a data Storage unit
`which compares addresses of the logs and Stores data
`corresponding to the same page in a corresponding area of
`the non-volatile memory.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The above and other objects and advantages of the present
`invention will become more apparent by describing in detail
`preferred embodiments thereof with reference to the
`attached drawings in which:
`FIG. 1 shows a conceptual view of a structure of a smart
`card and a System utilizing the Smart card;
`FIG. 2 is a conceptual view of an application program
`used in a Smart card;
`FIG. 3 is a flowchart showing transaction processing in a
`Smart card;
`FIGS. 4A and 4B are flowcharts showing a method of
`Storing data by the unit of log in a Smart card according to
`the conventional new-value logging,
`FIGS. 5A, 5B, and 5C are flowcharts showing a method
`of Storing data by the unit of page in a Smart card, according
`to an embodiment of the present invention; and
`FIG. 6 is a conceptual view of a transaction buffer.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`The present invention will now be described more fully
`with reference to the accompanying drawings, in which
`preferred embodiments of the invention are shown.
`FIG. 1 shows a conceptual view of a structure of a smart
`card and a System utilizing the Smart card. In a host or
`terminal 10, operation requests for application programs,
`which activate the Smart card, are generated by client
`programs. A non-volatile memory, such as an EEPROM, and
`a volatile memory, Such as a random access memory (RAM),
`are included in a Smart card 20. The Smart card 20 includes
`the application programs as a Server capable of processing
`the operation requests generated in the host or terminal 10.
`FIG. 2 is a conceptual view of an application program
`used in a Smart card. The application programs, which are
`included in the Smart card 20, are card applets 30 that are
`constituted of Java codes, and thus a Smart card having a
`platform capable of executing application programs Such as
`the card applets 30 is called “Java (smart) card”. Here, the
`Java (Smart) card denotes a Smart card that has a Java (Smart)
`card application program running platform. The Java (Smart)
`card application program running platform provides appli
`cation programs, which are constitute of Java codes, to a
`Smart card. In the Java (Smart) card, a Smart card operating
`system 60 in which module units are included for transaction
`processing is not the java-based, instead, a Java Virtual
`machine 40 is usually placed over the Smart card operating
`System 60 to run the Java application program. Accordingly,
`transaction management of a transaction management mod
`ule 61 can be applied to the transaction processing in other
`kinds of Smart card as well as in the Java (Smart) card.
`In order to run a Java applet, the Java virtual machine 40
`is placed on the Smart card operating System 60, and a native
`interface 50 exists for connecting the Java virtual machine
`40 with the Smart card operating system 60. The transaction
`management module 61, a memory management module 62,
`utility device drivers 63, and a cryptographic module 64 are
`included in the Smart card operating System 60. The trans
`action management module 61 manages a transaction pro
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`ceSS related to the present invention. The memory manage
`ment module 61 manages the use of the memory, and the
`utility device drivers 63 include device drivers used for a
`contacting area with card hardware (HAN) 70, and other
`useful utilities. The cryptographic module 64 manages cryp
`tographic operations.
`In order to guarantee atomicity in writing data to the
`non-volatile memory and consistency of data between the
`application programs, a transaction is performed upon the
`unit to be particularly protected.
`The data-writing request in the non-volatile memory
`needs the transaction processing to guarantee atomicity.
`However, there are also Some writing requests which do not
`need to be particularly protected in the transaction proceSS
`ing. In general, a log is generated in response to the
`15
`data-writing request within the transaction processing. How
`ever, the same kind of the log can also be generated in
`response to data-writing request outside the transaction, and
`delayed writing is applied. Hereinafter, the present invention
`will be described mainly with respect to data writing within
`the transaction processing, but this description will be also
`applied to the data writing outside the transaction.
`FIG. 3 is a flowchart showing transaction processing in a
`Smart card that processes the transaction management mod
`ule 61 of FIG. 2.
`25
`Upon receiving a beginTransaction () 80 that requests the
`Start of the transaction processing to the Smart card operating
`System 60, the transaction management module 61 continues
`logging 90 until it receives a commitTransaction () 110 that
`requests completion of transaction processing to the Smart
`card operating System 60. Logging can be divided into
`old-value logging and new-value logging according to an
`order of logging of data, the data to be updated during the
`transaction processing.
`In the old-value logging, log is generated by producing
`backup of the data to be updated and corresponding
`addresses. In the new-value logging, log is directly made of
`the data to be updated and corresponding addresses. Since
`costs of old-value logging and new-value logging in commit
`transaction processing and abort transaction processing are
`different, the more appropriate one of two loggings is
`Selected according to use environment. In the Smart card 20,
`the possibility of card tear is high during transaction pro
`cessing. Accordingly, new-value logging is more appropri
`ate because cost in abort transaction processing is lower in
`new-value logging.
`When power supply to the Smart card 20 is interrupted
`during logging, or if it is determined that transaction pro
`cessing cannot be performed any more, the transaction
`management module 61 calls abortTransaction () 100 that
`requests the Stop of the transaction processing, and then the
`System returns to an initial State prior to Start of the trans
`action processing.
`FIGS. 4A and 4B are flowcharts showing a method of
`Storing data by the unit of log according to the conventional
`new-value logging. FIGS. 5A, 5B, and 5C are flowcharts
`showing a method of Storing data by the unit of page in a
`Smart card according to an embodiment of the present
`invention. Because the present invention is based on new
`value logging, data update by the unit of page and delayed
`60
`writing of the present invention will be described by com
`paring FIGS. 4 and 5.
`FIGS. 4A, 5A, and 5B illustrate a normal flow where
`transaction processing is normally performed from receiving
`beginTransaction () 80 to receiving commitTransaction ()
`110. FIGS. 4B and 5C illustrate a flow when card tear
`occurs, which means that power Supply to the Smart card 20
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`is interrupted during the transaction processing and power is
`supplied again. However, FIGS. 4B and 5C can also be
`applied to a case where abortTransaction () 100 is called
`during transaction processing instead of power interrupt.
`If the system receives beginTransaction ( ) 80 that
`requests the Start of the transaction processing, it enters a
`State of the transaction processing by Setting a flag indicating
`that the Smart card 20 is under transaction processing (steps
`120 and 150). A response to beginTransaction () 80 is sent
`to a host or terminal 10 which calls beginTransaction () 80
`(steps 121 and 151). Then, logging is performed to RAM
`according to each data-writing request (Steps 122 and 152).
`Logging is performed by Storing the address of the
`non-volatile memory to Store the data, and the content of the
`data, in the RAM.
`It is determined that whether abortTransaction () 100 is
`received, and if abortTransaction () is received, the System
`goes back to the state prior to step 80. If commit Transaction
`() 110 is called during logging, logs written in the RAM are
`transferred to the transaction buffer of the EEPROM (steps
`124 and 154).
`In the conventional new-value logging of FIG. 4A, data is
`written to the appropriate location of EEPROM according to
`the log by the unit of log (step 155), and thus the response
`to the commitTransaction ( ) is sent after all contents of
`EEPROM is updated according to the logs. That is, the Smart
`card 20 is blocked while all contents of the memory are
`updated, and thus a delay occurs. After that, the Smart card
`20 enters a State of completion of the transaction processing
`(step 156), and a response to commitTransaction () 110 is
`sent to a host or terminal 10 (step 157).
`Referring to FIGS. 5A and 5B for the present invention,
`after logs of the RAM are transferred to the transaction
`buffer of the EEPROM (step 124), a response to commit
`Transaction () 110 is sent to a host or terminal 10 (step 125).
`Thus, a host or terminal 10 is in states of completion of the
`transaction, while the Smart card operating System 60 is in
`a State of transaction processing.
`When a data-writing request is sent to the EEPROM, it is
`checked whether logs are left in transaction buffer (Step
`126). If there are logs left, the System searches the logs
`which contain the address that belongs to the Same page as
`the address for the data-writing request (step 127). All the
`logs corresponding to the same page to which the address of
`the data-writing request belongs are Searched, and the data
`of all the logs corresponding to the same page are updated
`at once (step 128). If corresponding logs do not exist, only
`the data for data-writing request is updated (step 130).
`Updating the data by the unit of page means reading the
`page of the non-volatile memory to be updated, Storing the
`page in the RAM, writing data in the page of RAM, and
`Writing the contents of the page of RAM in the page of the
`non-volatile memory by the unit of page at a time. When all
`the logs are updated, the Smart card 20 enters a State of
`completion of the transaction processing (step 131).
`FIG. 4B illustrates a flow when card tear occurs, that is,
`when power Supply to the Smart card 20 is interrupted, in the
`conventional new-value logging. If the power is Supplied
`again, it is determined whether any transaction processing
`was in progress (Step 160), and data is written in the
`EEPROM by the unit of log if transaction processing was in
`progress (step 161). After that, a response to abortTransac
`tion () 100 is sent, and the Smart card 20 enters a state of
`completion of the transaction (step 156).
`FIG. 5C illustrates a flow when power supply is inter
`rupted during logging in a method of Storing data by the unit
`of page according to the present invention. It is determined
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`whether any transaction processing was in progress (Step
`140). The data for the logs left in the transaction buffer are
`updated by the unit of page if there was no transaction in
`progreSS. However, the logs remaining in the transaction
`buffer can be handled later, which gives flexibility.
`In case of FIG. 4B, abortTransaction () 100 is called to
`handle parts of the transaction buffer which are not updated.
`If card tear occurs during updating, all logs of data are
`updated again by the unit of log ignoring previous updating
`(step 161).
`However, in case of FIG. 5C, if logs in RAM are not
`transferred to the transaction buffer of the EEPROM when
`abortTransaction () 100 is called, the Smart card 20 goes just
`to State prior to the transaction. If logs are transferred to the
`transaction buffer of EEPROM, the updated pages are not
`updated again, and remaining pages other than the updated
`pages are updated by the unit of page. Therefore, according
`to the present invention, in a contactleSS card where the
`possibility of card tear is high, costs for handling are much
`lower than the conventional art.
`If the transaction buffer is empty (step 144), the Smart
`card 20 enters a State of completion of the transaction (Step
`131). A response to abortTransaction () 100 is sent when an
`external State goes back to a State prior to Start of the
`transaction (step 142) whereas the response to abortTrans
`action () 100 is sent when the transaction buffer of the
`EEPROM is empty (step 162) in FIG. 4B. In the present
`invention, the update of transaction buffer is delayed
`because logs remaining in the transaction buffer can be
`handled in the time gap between transactions, or they can be
`handled while the logs for next transaction are written to
`RAM. Thus, the cost is minimized for the writing between
`transactions.
`FIG. 6 is a conceptual view of a transaction buffer. In the
`conventional art, the transaction buffer is always used from
`its front part to rear part. Thus, usually, the front part is used
`more than the rear part. In order to Solve this problem, an
`occupied page 171 and an unoccupied page are distin
`guished and managed as a linked list 172. The pages are
`usually managed as a circular queue Structure 170. However,
`Since the pages are not always occupied consecutively, it is
`possible to give preference to the unoccupied page by
`indicating an order of using the pages through the linked list
`172 So that the unoccupied pages can be occupied first later.
`The whole memory of the EEPROM can be also managed
`like this.
`AS described above, the method of Storing data in a
`non-volatile memory according to the present invention
`reduces the number of write accesses to the EEPROM and
`delays in a time response by reducing the time lost by the
`delayed writing. That is, logs generated by the data-writing
`request are treated Separately according to pages of
`EEPROM, and only one access to the EEPROM is needed
`in each page by updating the logs by the unit of page at a
`time. Such update by the unit of page is very efficient
`considering the time lost which is inevitable in the
`EEPROM. The transaction buffer of EEPROM is managed
`by a circular queue Structure or a linked list for uniformly
`using the pages. Write update by the unit of page or
`management of the memory in the EEPROM according to
`the present invention can also be applied to writing or
`managing of the whole memory of the Smart card. It is also
`possible to delay updating of the data until the CPU is
`available. The management of the transaction buffer by the
`linked list makes overlapped transactions and multiple trans
`actions possible in the Smart card because many linked lists
`can be provided if logs of one transaction are provided to
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`each list. The overlapped transaction may be implemented
`by including logs of a Sub-transaction in one list.
`In the implementation of transaction for the device having
`a limited memory including the non-volatile memory, we
`should consider hardware characteristics of the memory, and
`which of them will be given priority. If the performance of
`the memory is important, a response time, a memory capac
`ity needed by the device, and the lifetime of the device have
`to be considered. If the service is provided directly to a user
`and the response time is important in the Service, the
`memory capacity needed and the lifetime of the device can
`be properly adjusted. If characteristics of the application
`program of the device are considered, more appropriate
`transaction processing may be implemented. If the number
`of logs generated during transaction processing is usually
`Small, the old-value logging can be used. However, if data
`of addresses corresponding to one page or two pages of the
`EEPROM is required to be updated, the data can be updated
`by the method of Storing data according to the present
`invention, and it can provide an improved response time.
`The present invention may be embodied as a computer
`readable code (including devices having an information
`processing function) on a computer readable medium. The
`computer readable medium includes Storage media on which
`computer readable data are Stored. The computer readable
`storage media include ROMs, RAM's, CD-ROMs, mag
`netic tapes, floppy disks, floppy disks, etc.
`AS described above, according to a method of Storing data
`in a non-volatile memory, it is possible to Shorten the delayS
`in Storing data, reduce the number of accesses to the
`non-volatile memory, and uniformly write data in the whole
`non-volatile memory, thereby shortening a response time of
`the non-volatile memory and expanding the lifetime of the
`non-volatile memory.
`While this invention has been particularly described with
`reference to preferred embodiments thereof, it will be under
`stood by those skilled in the art that various changes in form
`and details may be made therein without departing from the
`Spirit and Scope of the invention as defined by the appended
`claims and equivalents thereof.
`What is claimed is:
`1. A method of Storing data in a non-volatile memory, the
`method comprising:
`(a) in response to a data-Writing request, generating and
`Storing logs in a volatile memory, including data to be
`Stored and an address of the non-volatile memory; and
`(b) comparing addresses of the logs and storing data
`corresponding to the same page by the unit of page in
`a corresponding area of the non-volatile memory, and
`wherein step (b) further comprises:
`(b1) copying the logs of the volatile memory to a trans
`action buffer of the non-volatile memory;
`(b2) comparing the addresses of the data logged in the
`transaction buffer to addresses for the data-writing
`request and Searching for the logs in the transaction
`buffer which contains the data logged with the
`addresses corresponding to the same page as the
`address for the data writing request;
`(b3) copying the page of the non-volatile memory which
`the address for the data writing request belongs to, to
`the Volatile-memory;
`(b4) Storing the data for the writing request in a page area
`of the volatile memory at the location with its same
`offset in a page of the non-volatile memory;
`(b5) Storing the data logged in the page area of the volatile
`memory according to the logs corresponding to the
`Same page,
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`IPR2022-00602
`Apple EX1055 Page 13
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`(b6) copying the page of the volatile memory to the page
`area of the non-volatile memory in order to update the
`page area of the non-volatile memory; and
`(b7) removing the logs reflected to update the page of the
`non-volatile memory from the transaction buffer in the
`non-volatile memory.
`2. The method of claim 1, wherein step(b) further com
`prises Storing the logs of the volatile memory in a transaction
`buffer of the non-volatile memory wherein the transaction
`buffer has a structure of one of a queue, a circular queue, and
`a linked list.
`3. A method of Storing data in a non-volatile memory, the
`method comprising:
`(a) upon receipt of a request for start of transaction
`processing, generating a log including data to be Stored
`and an address of the non-volatile memory in response
`to the data-writing request until a request for comple
`tion of transaction processing is received;
`(b) upon receipt of the request for completion of trans
`action processing, Storing the logs in a transaction
`buffer of the non-volatile memory;
`(c) comparing addresses of the logs in the transaction
`buffer to addresses of the data-writing request and
`Storing data from the transaction buffer corresponding
`to the same page of the data-writing request in a
`corresponding area of the non-volatile memory by the
`unit of page;
`(d) updating the non-volatile memory by unit of page; and
`Step (c) further comprises:
`(c1) comparing addresses of the data logged in the trans
`action buffer with the addresses of the data-writing
`request and searching for the logs in the transaction
`buffer corresponding to the page the data is logged
`belongs to, wherein the page the data is logged to
`belongs to the same page as the address for the data
`Writing request;
`(c2) copying the pages of the non-volatile memory which
`the address for the data-Writing request belongs to, to
`the Volatile memory;
`(c3) storing the data in a page area of the volatile-memory
`according to the logs corresponding to the Same page as
`the address for the data-writing request;
`(c4) copying the page of the Volatile memory to a page
`area of the non-volatile memory; and
`(c5) removing the logs from the transaction buffer corre
`Sponding to the same page.
`4. The method of claim 3 wherein step (c) comprises
`comparing addresses of the non-volatile memory required
`by the data-writing request and the addresses of the logs in
`the transaction buffer upon receipt of the data-writing
`request and Storing data corresponding to the same page in
`the corresponding area of the non-volatile memory by the
`unit of page.
`5. The method of claim 4, wherein step (c) further
`comprises:
`(c1) determining whether the logs of which addresses are
`included in the same page as the page in which the
`address required by the data-writing request exist;
`(c2) if the logs exist, storing the data in a corresponding
`page of the non-volatile memory according to the logs
`and the data-writing request; and
`(c3) if the logs do not exist, Storing data in a correspond
`ing page of the non- memory according to the data
`Writing request.
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`6. The method of claim 5, wherein the method is imple
`mented in a device having a volatile memory, and step (c2)
`further comprises:
`(c21) copying a page of the non-volatile memory required
`by the data-Writing request to the Volatile memory;
`(c22) storing data in a corresponding are of the volatile
`memory according to the logs and the data-writing
`request,
`(c23) copying the corresponding area of the volatile
`memory to a page area of the non-volatile memory; and
`(c24) removing the logs.
`7. The method of claim 3, wherein if a request for stop of
`transaction processing is received during step (a), the logs
`generated in Step (a) are removed, and the method is
`performed again from Step (a) for the next transaction.
`8. The method of claim 3, wherein if a request for stop of
`transaction processing is received during step (b) before all
`the logs are Stored in the transaction buffer, the logs Stored
`in the transaction buffer are removed, and the method is
`performed again from Step (a) for the next transaction.
`9. The method of claim 3, wherein step (b) comprises
`Storing logs separately according to pages of the non-volatile
`memory in the logs.
`10. The method of claim 3, wherein steps (a) through (c)
`are performed for consecutive transaction processing, and
`Step (c) of transaction processing and step (a) of next
`transaction processing are performed in parallel.
`11. The method of claim 3, wherein the transaction buf