Data brown-out protection method for NOR flash memory

Abstract

The present invention provides a data brown-out protection method for an NOR flash memory. The method includes the following steps: step one: separately dividing an array for storing mark structured data from a first sector of a data storage area of the NOR flash memory, wherein the array for storing the mark structured data is a mark structured array, and the sector is a mark storage area, and the mark structured data contains a memory address value, a length value, a backup symbol value, a backup address value and a memory mark value; step two: establishing a mapping table in a next sector of the data storage area of the NOR flash memory, wherein each table entry in the mapping table corresponds to a basic erasing unit of the data storage area; step three: finding the mapping table to identify the backup address; step four: integrating and writing data to be overwritten into the backup address, and rewriting the backup address value, memory address value, length value and backup mark value of the mark structured data; and step five: writing the backup data into the data storage location, and rewriting the storage mark value.

Description

technical field [0001] The invention relates to a data power-down protection method, in particular to a data power-down protection method for NOR flash memory. Background technique [0002] Flash memory chip is a commonly used memory chip that can still save data in the case of power failure, and is widely used in embedded systems. The current flash memory is mainly divided into NOR FLASH and NAND FLASH, both of which are erased in units of blocks, but NOR FLASH can be written in units of bytes, and the data in it can be read directly. [0003] The flash memory is generally divided into sectors on the physical medium, and the write operation to the flash memory is based on the sector, and the entire sector needs to be erased before the write operation can be performed, that is, assuming that the user only needs to write a word section, it is also necessary to perform an erase first and then write operation on the entire sector. The steps of writing operation to flash memor...

AI Technical Summary

Problems solved by technology

[0010] 5. NOR FLASH can be accessed randomly and supports direct code execution, but NAND FLASH does not support it;

[0012] 7. NOR FLASH has high cost and small capacity, and is more used for executable programs in embedded systems

In the second method, repeatedly writing data to the flag information at the same location and to the same backup area will cause these areas to be damaged first, and repeatedly erasing and writing the flag information will also bring a lot of overhead

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