US 12,001,280 B2 · Overcoming error correction coding mis-corrects in non-volatile memory

Abstract

Error correction coding (ECC) mis-corrected reads, if undetected, result in silent data corruption of a non-volatile memory device. Overcoming ECC mis-corrected reads is based on a read signature of a result of reading a page in the non-volatile memory device. An ECC mis-correct logic counts the number of bits in the end-most buckets into which the bits of the result is divided. End-most buckets that are overpopulated or starved reveal a tell-tale read signature of an ECC mis-correct. The ECC mis-correct is likely to occur when the read reference voltage level used to read the page is shifted in one direction or another to an extreme amount that risks reading data from a different page. Detecting ECC mis-corrected reads can be used to overcome the ECC mis-corrects and mitigate silent data corruption.

Claims21

Dependent claims

A memory controller comprising:

a read logic to apply a read voltage shift to a read reference voltage level in advance of a read of a page of non-volatile memory cells encoded to store multiple pages;
an error correction coding (ECC) logic to verify that the read of the page was correct;
a mis-correct logic to detect silent data corruption in a non-volatile memory device in which the page is located, including to determine whether the read of the page verified as correct is instead an ECC mis-correct;
and
wherein the ECC mis-correct is determined based on a read signature of a result of the read that indicates the result includes data from a different page.

2 more elements

A computer-implemented method comprising:

applying a read voltage shift to a read reference voltage level in advance of a read of a page of non-volatile memory cells encoded to store multiple pages;
verifying that the read of the page was correct in accordance with an error correction coding (ECC) logic;
detecting silent data corruption in a non-volatile memory device containing the non-volatile memory cells in which the page is encoded, including determining whether the read of the page verified as correct is instead an ECC mis-correct;
and
wherein the ECC mis-correct is determined based on a read signature of a result of the read that indicates the result includes data from a different page.

2 more elements

A storage system comprising:

an array of non-volatile memory cells encoded to store multiple pages at different read reference voltage levels;
and
a memory controller communicatively coupled to the array of non-volatile memory cells, the memory controller having a processor to:
apply a read voltage shift to a read reference voltage level in advance of a read of a page of non-volatile memory cells,
verify that the read of the page was correct in accordance with an error correction coding (ECC) scheme,
determine an ECC mis-correct based on a read signature of a result of the read that indicates the result includes data from a different page, and
detect silent data corruption in a non-volatile memory device containing the array of non-volatile memory cells in which the page is encoded after a determination that the read of the page verified as correct is instead the ECC mis-correct.

4 more elements

Dependencies are inferred from the claim text.

Overcoming error correction coding mis-corrects in non-volatile memory

Life of this patent

Overcoming error correction coding mis-corrects in non-volatile memory

Life of this patent

Abstract

Claims21