US 12,086,018 B2
Data retention management after power off
Lisha Wang, Fremont, CA (US); James Higgins, Chandler, AZ (US); Yongke Sun, Pleasanton, CA (US); and Lanlan Gu, San Jose, CA (US)
Assigned to WESTERN DIGITAL TECHNOLOGIES, INC., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Aug. 30, 2022, as Appl. No. 17/899,139.
Prior Publication US 2024/0070003 A1, Feb. 29, 2024
Int. Cl. G06F 11/07 (2006.01); G06F 1/30 (2006.01); G11C 29/52 (2006.01)
CPC G06F 11/076 (2013.01) [G06F 1/30 (2013.01); G06F 11/073 (2013.01); G11C 29/52 (2013.01)] 18 Claims
OG exemplary drawing
 
7. A method of management of data stored in a memory of a storage device, comprising:
saving metadata associated with one or more blocks of the memory prior to the storage device being powered off, the metadata indicative of the one or more blocks of the memory being a last one or more blocks of the memory to be programmed prior to the storage device being powered off;
reading the metadata upon powering on the storage device to determine the one or more blocks of the memory for measurement of an error rate;
measuring the error rate of the one or more blocks of the memory, wherein the measuring the error rate is triggered by the powering on of the storage device;
estimating, based at least in part on the error rate, a time shift indicative of a duration of time for which the storage device was powered off; and
setting a read level for multiple blocks of the memory, wherein the read level is determined based at least in part on the time shift.