Marking method and initialization method for a non-volatile memory array

Abstract

The invention proposes a marking method and an initialization method for a non-volatile memory array. The non-volatile memory array includes a plurality of storage units, and each storage unit includes a plurality of bytes. The marking method includes the following steps: determining whether the bytes of each storage unit can be accessed normally; and writing a mark to the storage unit. The initialization method includes the following steps: reading the mark of each memory unit; determining that the mark matches a preset value; recording the memory cells whose marks match the preset value into an identification table; and erasing the marks.

Description

technical field [0001] The invention relates to a marking method and an initialization method, in particular to a marking method and an initialization method for a non-volatile memory. Background technique [0002] Generally speaking, a non-volatile memory array (non-volatile memory array) is composed of multiple blocks, each block contains multiple pages, and each page contains multiple bytes. (byte). [0003] In existing memory arrays, a page is used as a data writing unit, and a block is used as a data erasing unit. That is to say, each page of a block can write a piece of data separately, but if the data of one page needs to be erased, the data of other pages of the block must be erased together. Therefore, when a certain page of a block is abnormal (cannot be accessed normally), the data erasure of the block cannot be performed, and the block should not be used, so as to avoid problems such as data reading errors or disappearance. [0004] Usually, after a memory arr...

AI Technical Summary

Problems solved by technology

Since the block as a whole is judged to be abnormal and discarded, other normally accessible pages or bytes in the block will also be unusable

In this way, the memory array may fail to meet the standard of good products; even if the memory array is finally judged to meet the standard, it will also cause low utilization due to discarding other pages or bytes that can be accessed normally

[0007] 2. When a block is judged as abnormal and needs to be written with a damage mark, it may be because the byte of the damage mark is written, which happens to be an abnormal byte, causing the write action to fail

Therefore, when the controller accesses the block judged to be abnormal for the first time, it misjudges the block as normal because it cannot read the damage flag.

[0008] 3. If data loss occurs in the byte storing the damage mark, the damage mark disappears, which will also cause the controller to misjudge the area that was originally judged to be abnormal because the damage mark cannot be read. block as normal

Afterwards, the controller will also use the area that was misjudged as normal because it cannot read the damage mark

[0010] 5. There may be a crosstalk effect between bytes. When the damage mark is written into a block that is judged to be abnormal, it will also affect other bytes. If the byte happens to be the block of another block Pre-marking the position will cause the controller to misjudge the normal block as abnormal

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