US 12,456,526 B2
In-nand read threshold voltage search system and method
Meysam Asadi, San Jose, CA (US); and Fan Zhang, San Jose, CA (US)
Assigned to SK hynix Inc., Gyeonggi-do (KR)
Filed by SK hynix Inc, Gyeonggi-do (KR)
Filed on Nov. 20, 2023, as Appl. No. 18/514,174.
Prior Publication US 2025/0166712 A1, May 22, 2025
Int. Cl. G11C 7/00 (2006.01); G11C 16/26 (2006.01); G11C 16/34 (2006.01)
CPC G11C 16/26 (2013.01) [G11C 16/3404 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A memory system comprising:
a controller configured to generate a read request; and
a memory device including:
at least one memory cell including a plurality of pages configured to store multiple data items; and
a pattern counter configured to:
receive, from the memory cell, a read data item, among the multiple data items, corresponding to the read request;
count, from the read data item, the number of cells reading as a particular value in multiple voltage level regions corresponding to multiple patterns for multiple pages among the plurality of pages, to generate count information; and
provide the count information to the controller,
wherein the controller is configured to:
receive the count information from the pattern counter;
identify a voltage level region with the least number of cells, among the multiple voltage level regions, based on the count information;
determine an optimal read threshold voltage based on the identified voltage level region; and
control the memory device to perform a next read operation by using the optimal read threshold voltage.