US 12,222,800 B2
Write and retire pages in QLC NAND blocks
Nikolaos Papandreou, Thalwil (CH); Timothy J. Fisher, Cypress, TX (US); Roman Alexander Pletka, Uster (CH); Charalampos Pozidis, Thalwil (CH); Radu Ioan Stoica, Zurich (CH); Aaron Daniel Fry, Richmond, TX (US); and Andrew D. Walls, San Jose, CA (US)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Jul. 7, 2023, as Appl. No. 18/348,416.
Claims priority of application No. 20230100177 (GR), filed on Mar. 2, 2023.
Prior Publication US 2024/0296085 A1, Sep. 5, 2024
Int. Cl. G06F 11/00 (2006.01); G06F 11/07 (2006.01)
CPC G06F 11/076 (2013.01) [G06F 11/073 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computer-implemented method for writing data to pages in a QLC block of a QLC NAND flash memory device, said device comprising a plurality of SLC pages organized in SLC blocks and a plurality of QLC pages organized in QLC blocks, said method comprising:
storing received data in SLC pages,
dividing equally a QLC block in a predefined number of sub-blocks according to a corresponding QLC page health status of said pages of said QLC block, and
upon determining that SLC pages are to be copied from SLC pages to QLC pages; copying device-internal said respective SLC pages to said sub-blocks of said QLC block using device-internal cache registers, wherein said copying is based on an error-count aware scheme.