Intelligent card and method for accessing flash memory of intelligent card

Abstract

The invention discloses an intelligent card and a method for accessing the flash memory of the intelligent card, relates to the field of intelligent cards and aims to solve the problem that a large quantity of flash memory interface functions need calling in a main program body when the intelligent card is accessed in the prior art. The method for accessing the flash memory of the intelligent card comprises the following steps of: setting the access right of a flash memory address to be unavailable to be read or written in an address protection unit; when a command code accesses a protected flash memory address, performing data exception processing to obtain the command type of the command code and command information corresponding to the command type; and accessing the flash memory of the intelligent card according to the command type and the command information corresponding to the command type. The invention also discloses the intelligent card for accessing the flash memory of the intelligent card by the method. The method is used for accessing a memory space by using the intelligent card.

Description

technical field [0001] The invention relates to the field of smart cards, in particular to a smart card and a method for accessing the flash memory of the smart card. Background technique [0002] The smart card hardware structure generally includes a central processing unit (CPU), random access memory (RAM), programmable read-only memory (EEPROM) and read-only memory (ROM). EEPROM is a non-volatile storage unit. Because of its high cost and small storage space, it is gradually replaced by NOR FLASH and NAND FLASH with mature technology, low cost and large storage space. Both NOR FLASH and NAND FLASH are flash memory chips, which are non-volatile memories that are erased and reprogrammed in blocks. [0003] In the actual program writing process, when it is necessary to access the flash memory, its read and write operations need to be erased by block, and then written. Generally, this process is through calling a specific flash memory in the main program written. Interface ...

AI Technical Summary

Problems solved by technology

If the RAM space is not managed well, it is easy to generate RAM space fragmentation, and at the same time, it will have a great impact on the readability and simplification of the code.

[0005] Especially for some transplantation projects, if the program on the original development platform is written in C language, choose to access the structure space in RAM by byte by pointer, and if the program on the target development platform needs to save the structure data in the flash memory, then To access the structure data of the flash memory space by byte by pointer, it is necessary to call the flash interface function many times, and modify the original program code a lot, which will bring great disadvantages to the transplantation of the program, and is prone to errors.

[0006] To sum up, the existing methods for accessing the flash memory of the smart card need to call a large number of flash memory interface functions in the main program body, resulting in cumbersome access to the flash memory and error-prone problems

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