JP2003331239A - Ic card having memory rearrangement function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an IC card capable of removing memory fragmentation or inconvenience on using at the empty memory coupling time. <P>SOLUTION: The memory fragmentation state is detected by a memory fragmentation detection means 11 at the IC card starting time, and the detected information is stored in a storage means 12 as management data in the IC card, and memory rearrangement is performed by a control means 13 by utilizing an idle time in the command waiting state from an external terminal, to thereby perform empty memory coupling automatically. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card capable of automatically eliminating a memory fragmentation state. 2. Description of the Related Art In an IC card having a nonvolatile memory capable of loading and deleting a plurality of applications and an IC chip with a CPU, a plurality of applications are usually loaded in a continuous area of the nonvolatile memory. I have. FIG. 5 is an explanatory diagram when a plurality of applications are loaded. In the IC card, since the capacity of the working RAM is small, the application is stored in a continuous area of the nonvolatile memory so as not to reduce the execution speed. For example, when the applications 1, 2, and 3 are loaded into the non-volatile memory 10 in this order as shown in the figure, each application is stored in a continuous area, and the area after the area where the application 3 is stored is an empty area. Become. A, B, C, and D in the figure represent the sizes of the respective areas. At this time, the start address and area size of each application are written as management data in a non-volatile memory area (not shown) managed by the OS. When an application is deleted in an IC card in which an application is mounted in a continuous area, memory fragmentation does not occur when the application is deleted in a reverse order to that when the application is mounted. As shown in (2), when the application 2 is deleted, an empty area is generated before and after the application 3. As described above, when the free area is divided into two areas, even if the total size of the free area can be mounted, it is impossible to additionally install an application larger than each divided area size. [0004] For this reason, it is necessary to change the mounting position of the application in order to combine the divided areas. However, in the case of an IC card, it takes time to write data into the nonvolatile memory. For this reason, when the size of the application becomes large, the processing time for executing the memory rearrangement before the normal use of the IC card increases, and the inconvenience of having to wait for the use occurs. It is also conceivable to execute memory relocation at the time of deleting an application, but it is inconvenient and irrational to wait a long time due to memory relocation, although a new application may not be loaded. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide an IC card which can eliminate memory fragmentation and inconvenience in use when free memory is combined. Aim. Therefore, the present invention provides a nonvolatile memory, a CPU,
In an IC card provided with an attached IC chip, fragmentation detection means for detecting a fragmented free memory at the time of starting the IC card, storage means for storing detection information of the fragmentation detection means, and a command from an external terminal Memory control means for reading the contents of the storage means in a waiting state and executing memory relocation when memory relocation is required. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram illustrating an IC card having a memory relocation function of the present invention, and FIG. 2 is a diagram illustrating a memory relocation function of the present invention. This embodiment is directed to an IC card including a nonvolatile memory in which a plurality of applications can be installed and deleted, and an IC chip (not shown) with a CPU. In FIG. 1, in a nonvolatile memory 10 in an IC card, applications 1, 2, and 3 are stored in a continuous area in this order as in the case of FIG. It is assumed that the size of each area is A, B, C, D. Here, as in the case of FIG. 6, if the application 2 is deleted, an empty area is created before and after the application 3. The divided memory free area is detected by, for example, the fragmentation detection unit 11 configured by the control program of the OS unit when the power is supplied from the external terminal and the OS unit is started, and the fragmentation detection information is It is stored in the storage means 11.
The fragmentation detection information is, for example, the presence / absence information of fragmentation, the start address of each free memory and the area size when fragmentation is present, and the storage unit 11 is a part of the nonvolatile memory area of the IC card managed by the OS. is there. For example, the control means 13 constituted by a control program of the OS section reads out the fragmentation detection information from the storage means 11 using the idle time in a command waiting state from an external terminal, and the fragmentation occurs. If there is, relocate the memory and combine the free areas. In this example, as shown in FIG.
The application 3 is moved so that the start address of the application 3 is continuous with the application 1. This movement processing is performed by copying (writing) a part of the application 3 into the free area, and sequentially overwriting the copied part of the application 3 when the free area B is completely filled. When the movement processing is completed, The free areas are merged, and the size becomes B + D. It should be noted that since the process of combining free areas takes time, if a command is received during the process, the process is interrupted, and the process is continued again after waiting for a command waiting state. In this case, the moving application 3
Is available as long as it does not overwrite its own area, because it exists completely in the old area. FIG. 3 is a diagram for explaining a memory fragmentation detection processing flow performed when the IC card is activated. Power is supplied from an external terminal to the IC card, and the IC card
When the S unit is activated (step S1), fragmentation detection processing is performed (step S2), and the detected fragmentation information is stored (step S3). FIG. 4 is a diagram for explaining a memory relocation processing flow performed in a command waiting state. It is determined whether or not it is waiting for a command from an external terminal (step S10), the fragmentation information stored during the command waiting state is read (step S11), and memory relocation processing is executed (step S12). As described above, according to the present invention, the application time in the IC card is automatically rearranged, so that the processing time when deleting the application or using the card can be shortened. Highly convenient IC for users
Cards can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of an IC card having a memory rearrangement function according to the present invention. FIG. 2 is a diagram illustrating a memory relocation function of the present invention. FIG. 3 is an explanatory diagram of a fragmentation detection processing flow when an IC card is activated. FIG. 4 is an explanatory diagram of a memory relocation processing flow in a command waiting state. FIG. 5 is an explanatory diagram when a plurality of applications are loaded. FIG. 6 is a diagram illustrating deletion of an application. [Description of Signs] 10 ... Non-volatile memory, 11 ... Fragmentation detection means, 12
... storage means, 13 ... control means.

Claims (1)

Claims: 1. An IC card equipped with a non-volatile memory capable of loading and deleting a plurality of applications and an IC chip with a CPU, and a fragmentation detecting a fragmented free memory when the IC card is activated. Detecting means, storing means for storing detection information of the fragmentation detecting means, reading the contents of the storing means in a state of waiting for a command from an external terminal, and executing memory relocation when memory relocation is necessary. An IC card having a memory rearrangement function, comprising: a memory control unit that executes.