Patent Application
20150199282
The present invention provides a scramble random seed prediction method with the storage device built-in data copy back procedure.
The new generation storage device (such as flash memory) is sensitive to data pattern. If data pattern programmed to a storage device is dull, the data would be disturbed easily. In order to avoid this situation, the controller would scramble data before programming data to the storage device. The storage device makers also suggest a best scramble rule to protect data from being unstable. The best scramble rules usually depend on programmed page number.
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In order to enhance data movement efficiency, controller will use the storage device built-in data copy back procedure to move data from the page N of the block A to the page M of the block B without reading the data to the buffer of the controller. The data pass through storage device internal register and program to another address directly. It means moved data move from the page N of the block A to the page M of the block B without re-scrambled. Moved data without re-scramble is more unstable than the data with re-scrambled, because the random seed maybe not match the value that storage device maker suggested.
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An objective of this invention is providing a method to predict a scramble random seed before first time programming. The data may be programmed to the page N of block A, and the data management algorithm predict that the data would be moved to the page M of the block B later. The scramble random seed with the data programmed to the page N of block A, would be related to the page M. After data is moved from the page N of the block A to the page M of the block B with the storage device built-in data copy back procedure, the data in the page M of the block B may be have the best scramble random seed which is related to the page M.
To achieve above objectives, a scramble random seed prediction method with the storage device built-in data copy back procedure is provided, and the steps of the method are comprising:
Further features and advantages of the present invention will become apparent to those of skill in the art in view of the detailed description of preferred embodiments which follows, when considered together with the attached drawings and claims.
All the objects, advantages, and novel features of the invention will become more apparent from the following detailed descriptions when taken in conjunction with the accompanying drawings.
Referring now to the drawings where like characteristics and features among the various figures are denoted by like reference characters.
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The scramble random seed prediction method with the storage device built-in data copy back procedure is provided and the steps are:
That is, conventionally, the controller may program data to page N of the block A with scramble random seed is relative to page N. In the invention, it is predicted that the data programmed to page N of the block A would be moved to the page M of block B, the scramble random seed with the data programmed to the page N of block A would be related to the page M. As an example, if controller received the host data, which would be programmed to Page 3 of the Block 5. And the data management algorithm predicts that the data would be moved to the Page 100 of the Block 10 later. The scramble random seed programmed with the data shall be a scramble random seed related to Page 100.
Therefore, compared to the conventional method of scrambling data or data movement, the moved data of this invention may be much more stable with the storage device built-in data copy back procedure.
Although the invention has been explained in relation to its preferred embodiment, it is not used to limit the invention. It is to be understood that many other possible modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention as hereinafter claimed.
