Intel® Agilex™ Hard Processor System Technical Reference Manual

ID 683567
Date 2/14/2023
Public

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15.5.2.4. Read-Modify-Write Operations

To read a specific page or modify a few words, bytes, or bits in a page, use the RMW operations. A read command copies the desired data from flash memory to a page buffer. You can then modify the information in the buffer using MAP00 buffer read and write commands and issue another command to write that information back to the memory.

The read‑modify‑write command operates on an entire page. This command is also useful for a copy type operation, where most of a page is saved to a new location. In this type of operation, the NAND flash controller reads the data, modifies a specified number of words in the page, and then writes the modified page to a new location.

Note: Because the data is modified within the page buffer of the flash device, the NAND flash controller ECC hardware is not used in RMW operations. Software must update the ECC during RMW operations.
Note: For a read‑modify‑write command to work with hardware ECC, the entire page must be read into system memory, modified, then written back to flash without relying on the RMW feature.