Method and device for erasure balance of Nand Flash

Abstract

The invention discloses a method and a device for realizing erasure balance. The method comprises the following steps of: at least setting a first erasure time threshold value and a second erasure time threshold value less than or equal to the first erasure time threshold value; at least setting a first utilization frequency threshold value and a second utilization frequency threshold value more than or equal to the first utilization frequency threshold value; dividing physical blocks of a Nand Flash into different physical block intervals according to the first erasure time threshold value, the second erasure time threshold value, the first utilization frequency threshold value and the second utilization frequency threshold value; and respectively mapping logical blocks to the physical blocks inside the corresponding physical block intervals according to the utilization frequency and the original mapping relation of the logical blocks. The invention limits the increased erasure times of the physical blocks with more erasure times by mapping the physical blocks with the more erasure times to the logical blocks with less utilization frequency, prevents the storage space from being reduced because the erasure times of partial physical blocks is excessive by balancing the erasure times of the physical blocks of the Nand Flash, thereby prolonging the service life of the Nand Flash.

Description

technical field [0001] The invention relates to the technical field of memory, in particular to a method and device for erasing and equalizing a Nand Flash. Background technique [0002] Nand Flash has the characteristics of low cost, large capacity and good stability, and is widely used in the embedded field. [0003] The physical structure of Nand Flash is composed of page structure and block structure. The size of a page is 512Bytes, and each page has an additional area of ​​16Bytes Spare Area. This area is not a data area and can be used to store some information related to the page, such as Check code, etc.; a block consists of 32 adjacent pages (or 64 pages), which is 16KB (or 32KB). A page is the basic unit of a read operation, and a block is the basic unit of an erase operation. Before writing a certain area, if the area has been written before, you need to erase the entire block containing the area first (erase first and then write). Nand Flash needs to erase the...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved in the present invention is to provide a method and device for erasing equalization of Nand Flash, in order to solve the problem in the prior art that the life of Nand Flash is affected by too many erasing times of some physical blocks

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