US 11,868,647 B2
Nonvolatile memory device, with valley search for threshold voltage, memory controller, and reading method of storage device including the same
Youngdeok Seo, Seoul (KR); Jinyoung Kim, Seoul (KR); Sehwan Park, Yongin-si (KR); and Ilhan Park, Suwon-si (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Nov. 9, 2021, as Appl. No. 17/522,578.
Claims priority of application No. 10-2021-0026074 (KR), filed on Feb. 26, 2021.
Prior Publication US 2022/0276802 A1, Sep. 1, 2022
Int. Cl. G06F 3/06 (2006.01)
CPC G06F 3/0655 (2013.01) [G06F 3/0604 (2013.01); G06F 3/0679 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A nonvolatile memory device comprising:
a memory block including a first memory area connected to a first word line; and
control logic comprising:
an on-chip valley search (OVS) circuit configured to perform an OVS sensing operation on the memory block; and
a first buffer memory configured to store at least one variation table including variation information of a threshold voltage of memory cells connected to the first word line, obtained from the OVS sensing operation,
wherein the control logic is configured to:
perform a first reading operation on the first memory area in response to a first read command applied by a memory controller, the first reading operation including a first OVS sensing operation performed at a first OVS sensing level and a first main sensing operation performed at a first main sensing level reflecting the variation information in response to the first read command.