FR2612668A1 - Portable electronic device - Google Patents

Abstract

The invention relates to memory cards. A portable electronic device such as a memory card especially includes a data memory 12 and a control element 11 such as a microprocessor. The data memory includes a user area and an index area. The user area is intended to receive items of data while the index area is intended to receive index items each representing the length of a data item to be recorded in the user area, as well as the head address of such a data item. Application to electronic payment means.

Description

 The present invention relates to a portable electronic device, generally called a "smart card" or "memory card", which contains an integrated circuit chip comprising for example a non-volatile data memory and a control element such as a central unit.

The invention relates more particularly to a portable electronic device in which the data recording section of a data memory can be divided into a set of recording areas.

 We have very recently developed a portable data storage medium, called a "memory card".

The memory card contains an integrated circuit chip which includes a non-volatile data memory and a control element such as a central processing unit. The control element controls access to the data memory, thereby storing relevant data in the data memory, and for reading the data from the memory, in accordance with instruction data which is entered from an external terminal.

 The data recording section of the data memory is divided into a set of recording areas. Numbers, called "area numbers" are assigned to these recording areas. A logical access method is used which consists in accessing any desired recording area, designating the number which is assigned to the desired recording area.

 More specifically, to implement the logical access method, the data recording section of the data memory is divided into two large recording areas, namely a directory area and a user area. The user area is subdivided into a set of recording areas in which will be stored different data items for various uses. These recording areas are defined by the area definition data items that are recorded in the directory area. Each of these area definition data items includes area number data, head address data, size data, etc. The area number data represents the specific number of a recording area.

The head address data defines the position of the recording area. The size data indicates the size of the recording area.

 As an example, as described in the U.S. patent application. No. 696099 filed by Tamada et al., the address addresses of the recording areas of the user area are written to the directory area. Therefore, a physical address must be pre-established to distinguish the directory area from the user area. As a result, the memory card can only be formatted by the person who fully knows the data recorded in the data memory, as well as the recording capacity of the data memory. Once the boundary between the directory area and the user area has been set, it is no longer possible to expand or shrink the directory area.

 A write instruction is used to write data to the directory area, and a different write instruction is used to write data to the user area. In other words, the write instruction that has been given determines whether the data should be written to the directory area or to the user area. Consequently, when an incorrect write instruction is given, the data which must be written in the user zone is written in the directory zone, or conversely, the data which must be written in the directory zone is written in the user area. When such an erroneous data write operation is performed, the data which has been recorded in the directory area or the user area is inevitably destroyed.

 Because, as noted, different write instructions are used to write data to the user area and the directory area, the control program which is stored in the memory card is complex , and the control program which controls the terminal to use the memory card is also complex.

 The object of the invention is therefore to provide a portable electronic device, in which a directory zone can be defined without it being necessary to refer to a user zone, and for which it is therefore possible to easily carry out an operation of data formatting.

 Another object of the invention is to provide a portable electronic device in which the data recorded in a memory are protected against accidental destruction, and which can be operated under the control of a relatively simple program.

 The invention provides a portable electronic device which comprises memory means having a first recording area for recording a first group of data items, and a second recording area for recording a second group of data items, the second group of data items defining recording positions in the first recording area, to which the data items that are part of the first data items are to be recorded, the recording position of the first recording area recording immediately following the recording position of the second recording area; and control means for externally writing input data -including length data of the data items of the first group, in the second storage area of the memory means, in accordance with an order which is provided by an external device, calculating recording positions of the first recording area to which each data item of the first group is to be recorded, and adding the recording positions to the respective data items of the second group.

Other characteristics and advantages of the invention will be better understood on reading the following description of an embodiment, and with reference to the accompanying drawings in which
Figure 1 is a block diagram showing a terrinal in which a memory card, constituting a portable electronic device according to the invention, is inserted during its use;
Figure 2 is a block diagram showing the memory card according to the invention;
FIG. 3 represents the layout plan of the data in the data memory which is incorporated in the memory card;
Figures 4A to 4C are diagrams which explain how data is written to the directory area of the data memory; ;
FIGS. 5A to 5C are diagrams which represent some recording areas of the data memory, and explain how data is written to the directory area of the data memory;
FIG. 6 is a flowchart which explains the operation of the control element incorporated in the memory card, for defining the directory area of the data memory; and
Figure 7 is a flowchart which explains how data is written to the data memory.

 FIG. 1 shows a terminal into which a memory card 1 is introduced, which is a portable electronic device according to the invention, when this card has to be used. The terminal is designed to be used in a financial or payment payment system, and it includes a card read / write device-2, a control section 3, a keyboard 4, a CRT display 5, a printer 6 and a diskette unit 7. The memory card 1 can be electrically connected to the card reader / writer 2. The card reader / writer 2 is connected to the control section 3, which includes a unit power plant and the like.

 FIG. 2 shows the structure of the memory card 1. As can be seen, the memory card 1 comprises a control element 11 (for example a central unit), a data memory 12, a program memory 13 and a contact block 14. The data memory is a non-volatile memory, in which the recorded data can be erased. The program memory 13 is for example a read-only memory of the mask programming type and it records a program intended to control the control element 11. The contact block 14 can be electrically connected to the read / write device of card 2 of the terminal (FIG. 1). The components which are represented inside the rectangle (indicated by dotted lines), that is to say the control element 11, the data memory 12 and the program memory 13, are incorporated into a single chip or a single integrated circuit module which is embedded in the body of the memory card 1.

 The data memory 12 is for example an electrically erasable programmable read only memory (EEPROM), and it is used to record various kinds of data. As shown in FIG. 3, the data memory 12 comprises an indicator area 21, a directory area 22 and a user area 23. The directory area 22 stores various items of directory data (which will be described later), which divide the user area 23 into a set of recording areas. In other words, the directory data items define the recording areas. These recording areas, which form the user area 23, are used to record various data items.

 We will now explain how we proceed to write directory data items in the data memory 12. FIG. 4A is a diagram showing the data layout plan, in the initial state, for the data memory 12. FIG. 4B is a diagram showing the layout plan of the data of the data memory 12 in which directory data articles have been written. In this case, each directory data item which is written to the data memory 12 includes a user area number En0 and the data length E1 of the user area designated by the area number En0, as the shows Figure 5A.

The head address E ad of the user area indicated by the number En0, has not yet been written in the directory area 22. Consequently, the person who formats the memory card can write in the area of directory 22 of data of any desired size.

 After items of directory data (the user area number En0 and the data length E1) have been written to the data memory 12, an order to set up in the indicator area 21 an indicator of completion of setting parameters, not shown, is introduced into the memory card. Then, the control element 11 of the memory card 1 calculates the head addresses of the recording areas of the user area 23, from the position of the last directory data item which has been written, and lengths of data written in the recording zones of the directory zone 22, as the flow diagram of FIG. 6 makes it possible to understand it. The head addresses which are thus calculated are written in the head addresses E ad of the zones directory record, as shown in Figure 5B. It follows from this that the data memory 12 is formatted as shown in FIG. 4C.

FIG. 6 is a flowchart which explains how the control element 11 of the memory card 1 works to define the directory zone 22 in the data memory 12. On reception of an order which signals that a predetermined value representing the completion of the setting of parameters is written in the completion indicator of setting of parameters in the indicator area 21, the control element 11 which is incorporated in the memory card 1 sets the value "1 "in the register (not shown) which is incorporated in the memory card 1, in step S61. In the next step, S62, the control element 11 determines the head address of the user area 23, from the last directory data item which has been written in the directory area 22.A 1 In step S63, the control element 11 writes this head address into the head address Ead of the n-th (that is to say the first) directory registration area. Then the control element 11 calculates the sum S of the data length
E1 which is registered in the n-th directory registration area, and the head address Ead, in step S64.

In step S65, the element 11 increments the value of n by one. In step S66, the control element 11 writes the sum S in the head address Ead of the n-th directory recording area. Then, in step S67, the control element 11 determines whether the head addresses of all the directory recording areas have been written or not. If the answer is NO, steps S64, S65 and S66 are repeated. If the answer is YES, directory area 22 has been fully defined. Once the process is complete, the predetermined value representing the complete setting of the parameters is then established in the corresponding indicator, in the indicator area 21.

 As described above, after the control element 11 in the memory card 1 has received the above-mentioned command, data can be written to the directory recording areas until an indicator is set in the area indicators 21, and the head addresses of the recording areas of the user area 23 are written to the memory area 12. When the head address is written to all the directories, the value representing the completion parameters are set in the corresponding indicator in the indicator area 21. Consequently, the directory data items can be written to the data memory 12 without it being necessary to refer to the addresses of head into the user registration areas.

Until an indicator is set in the indicator area 21, the head addresses have not been defined in all of the user registration areas. Therefore, before the indicator is set up in the indicator area 21, any directory data item (e.g. data length), which has already been written, can be edited, and any record area of directory can be deleted. In summary, the directory area 22 can be modified before an indicator is set up in the indicator area 21. In addition, before an indicator is set up in the indicator area 21, the person formatting the memory 12 can write as many directory data items as it wants to this last.

 It is necessary to write directory data items to the data memory 12 so that these data items can be easily handled during the use of the memory card 1. For example, the data length E1 , that is to say the data "BBB" represented in FIG. 5A, must represent the sum of the length of data which the user of the smart card can use, and the length of data which is used for handling directory data items. However, it is not absolutely necessary to do so. It has been found that the memory card 1 can be used even if "BBB '" data recorded in the data memory 12, and representing the length of data that the user memory card can use, can be written to a directory recording area, as shown in Figure 5C, and this "BBB '" data can then be changed to new "BBB" data which is easier to handle , as shown in Figure 5B. In this case, the "BBB '" data is changed to "BBB" after an indicator has been set up in the indicator area 21. This method of modifying the data length obviously contributes to simplifying the writing of directory data items in data memory 12.

 The directory data items used in the use of the memory card are written to a sufficiently large storage area. Therefore, when new directory data articles are written on top of existing directory data articles, previously written data articles, as opposed to new directory data articles, are not erased. When writing new directory data items to old ones, that is, replacing old data items with new data items, the same positions are used, and the recording area that records directory data retains practically the same size as before the use of the memory card. As a result, the data memory 12 is used very efficiently. In any case, the format of the data memory 12 can be changed, without having to refer to the user area of the memory 12. In other words terms, the person formatting the memory card can define new directory recording areas even if he knows nothing of the previous format of the data memory 12.

 As previously described, the user record areas are not defined until all of the necessary directory data items have been written to data memory 12. These directory data items are written in a form which allows them to be inserted easily, and they are automatically changed so that they can be used more easily in the memory card, if the control element 11 in the memory card 1 confirms the order indicating the completion of the fixa tion of the parameters, as indicated above, after the memory card has been found usable, despite the directory data items that have been introduced. Therefore, as also indicated, the person who formats the card with memory can appropriately define new directory recording areas, even if it has no knowledge of the prior memory format 12. In addition, as long as an indicator has not been inserted in the s flag area 21, that person can rewrite or delete any directory data items, and they can write additional directory data items to data memory 12. In addition, directory data items can be written in memory 12 in a form making it possible to process them easily, with a relatively simple program. Directory data items are therefore processed quickly.

 According to the invention, it is possible to use the same write instruction to write data to the directory area 22 or to the user area 23. More specifically, an indicator which indicates whether the user area 23 can be used, is established in the indicator zone 21. Under the effect of the writing instruction provided by the control section 3 of the terminal (FIG. 1), the control element 11 accomplishes the operation which is indicated by the flowchart of Figure 7. First, the control element 11 determines, in step S71, whether the indicator set in the indicator area 21 indicates or not that the user area 23 can be used. If the answer is NO, all the data entered in the memory card 1 is written in the directory zone 22, in step S72. If the answer is YES, the data entered in the memory card 1 is written in the user area 23, in step S73. When the memory card 1 has received an order which commands to set the indicator corresponding to a value representing "the available state", and when the writing of the head addresses has been completed for. all the directories, the control element 11 fixes a corresponding value showing this available state.

 In other words, on receipt of a write instruction which comes from the control section 3 of the terminal, the control element 11 selects the directory area 22 or the user area 23, in accordance with the value of the indicator which is set in the indicator area 21. Consequently, it is not necessary to use two different writing instructions, that is to say an instruction requesting the writing of data in the directory area 22, and the other instruction requesting data to be written to user area 23, which eliminates the risk that necessary data stored in directory area 22 or in user area 23 will be destroyed when an erroneous write instruction is applied to the memory card. Furthermore, since the same write instruction is used to write data to the directory area 22 or to the user area 23, a relatively simple program is sufficient to control the writing of data to the data memory. 12.

 It goes without saying that numerous modifications can be made to the device and to the method described and shown, without going beyond the ambit of the invention.

Claims (17)

 1. Portable electronic device comprising memory means and control means for writing data introduced externally into the memory means, and for reading data from the memory means, characterized in that: the memory means (12) include a first recording area (23) for recording a first group of data items, and a second recording area (22) for recording a second group of data items, this second group of data items defining recording positions in the first recording area (23), in which the data of the first data items is to be recorded, the recording position of the first recording area (23) immediately following the recording position of the second recording area (22); and the control means (11) externally write input data, comprising length data of the data items of the first group, in the second recording area (22) of the memory means (12) , in accordance with an order which is provided by an external device, they calculate the recording positions of the first recording area (23) in which each data item of the first group is to be recorded, and they add the recording positions recording to the respective data items of the second group.  2. Portable electronic device according to claim 1, characterized in that the control means (11) write the length data of the data items of the first group in the second recording area, in the form of the data items of the second group, they calculate the recording position of a first data item of the first group, from the recording position of the last data item - of the second group, and they add the recording position to a first data item of the second group, and then they calculate the record position of any other data item of the first group, from the length data of the immediately preceding data item of the first group, and they add the recording position for each data item of the second group which corresponds to this data item of the first group.  3. Portable electronic device according to claim 1, characterized in that the storage position of the first data item of the first group, which is added to the first data item of the second group, contains the first address of the memory means.  4. Portable electronic device according to claim 1, characterized in that the memory means (12) further comprise a third recording area (21) intended to record identification data which indicate whether the first recording area (23) can be used or not, and the control means (11) places the identification data in the third memory area (21) after all the recording positions have been added.  5. Portable electronic device according to claim 4, characterized in that the third recording area (21) is established in a head portion of the memory means (12).  6. portable electronic device according to claim 4, characterized in that the control means (11) write the identification data in the third recording area (21) under the action of an order which comes from the external device .  7. portable electronic device according to claim 1, characterized in that the memory means (12) further comprises a third recording area (21) which is intended to record identification data which indicate if the first area d the recording (23) can be used or not, and the control means (11) select the first recording area (23) or the second recording area (22), in accordance with the identification data which are recorded in the third recording area (21), depending on a write order c = i is provided by the external device.  8. Portable electronic device according to claim 7, characterized in that the control means (11) write data in the first recording area (23) when the identification data have indicated that the first recording area ( 23) can be used.  9. Portable electronic device according to claim 7, characterized in that the writing order is used in common to write data in the first recording area (23) and in the second recording area (22).  10. Portable electronic device according to claim 7, characterized in that the third recording area (21) is established in a head portion of the memory means (12).  11. Portable electronic device according to claim 7, characterized in that the control means (11) calculate, in accordance with an order intended to control the establishment of the identification data, the memory position of each knowledge item- of the first group, from the memory position of the last data item of the second group and the length data of the immediately preceding data item of the first group, after which they add the recording position to the item of corresponding data from the second group, and they then establish the identification data.  12. Portable electronic device comprising data input / output means which are intended to receive data from an external device, and to supply data to the external device, memory means intended for recording data, and control means for writing data to and for reading data from the memory means, characterized in that: the data input / output means (14) receive a write command from the device external, and they transmit data to the external device; the memory means (12) includes a data recording area (23) for recording the data received from the data input / output means (14), a directory recording area (22) for recording directory data that defines the data recording area (23), and a flag recording area (21) for recording identification data that indicates whether the data recording area (23) can be used or not; and the control means (11) select the data recording area (23) or the directory recording area (22), in accordance with the identification data which is recorded in the indicator recording area ( 21), depending on the writing order which is applied to the input / output means (14) from the external device, so that the data which is supplied to the input / output means of data (14) are written to the recording area which is thus selected.  13. portable electronic device according to claim 12, characterized in that the control means (11) select the data recording area (23) when the identification data indicates that the data recording area (23) can be used.  14. Portable electronic device according to claim 12, characterized in that the writing order is used in common to write data in the area  data recording (23) and in the recording area  very repertoire (22).  15. Portable electronic device according to the re  vendication 12, characterized in that the recording area  ment of indicators (21) is established in a head portion  memory means (12).  16. Portable electronic device according to the re  vendication 12, characterized in that the means of control  from (11) write data to the recording area  indicators (21) on the basis of an external order, after  writing data to the re recording area  area (22), these data indicating that the recording area  data (23) can be used.  17. Portable electronic device, comprising  memory means and control means for writing  in the memory means of the data entered s so  external, and for reading data from the storage means  re, characterized in that: the memory means (12) com  carry a data storage area (23) for  record data items, and a recording area  very directory (22) for recording articles of  directory data that defines record positions  recording in the data recording area (23),  where the data items are to be stored  the recording position of the recording area  very data (23) immediately following the position  recording the directory recording area  (22); and the control means (11) write data  entered externally into the directory recording area (22) in accordance with an order which is provided  by an external device, this data entered includes  from length data items of data items they  calculate recording positions of the recording area  data storage (23) in which the articles. of  data must be recorded, these recording positions being obtained by adding the recording position of the last directory item and the length data of the data items, and they add the recording positions to the respective directory items.