System and method for lower page data recovery in a solid state drive

摘要

In some embodiments of the present invention, a data storage system includes a controller and a non-volatile memory array having a plurality of memory pages. The controller performs a method that efficiently resolves the lower page corruption problem. In one embodiment, the method selects programmed lower page(s) for which paired upper page(s) have not been programmed, reads data from those selected lower page(s), corrects the read data, and reprograms the read data into those lower page(s). Since the number of lower pages in this condition is typically low (e.g., several pages in a block with hundreds or thousands of pages), this is a much more efficient method than reprogramming the entire block. In another embodiment, a similar reprogramming method is applied as a data recovery scheme in situations in which only lower pages are programmed (e.g., SLC memory, MLC memory in SLC mode, etc.).

主权项

1. A solid-state storage system, including:
a non-volatile memory array including a plurality of memory blocks, each memory block including lower memory pages paired with upper memory pages; and a controller configured to:
select, from the memory blocks, a programmed lower memory page that has a paired upper memory page that has not been programmed;read first data from the selected lower memory page, wherein at least a portion of the read first data is corrupted;apply error correction to the read first data to generate corrected first data; andprogram the corrected first data to the selected lower memory page.