US 12,282,431 B2
Flash memory persistent cache techniques
Nadav Grosz, Broomfield, CO (US)
Assigned to Micron Technology, Inc., Boise, ID (US)
Filed by Micron Technology, Inc., Boise, ID (US)
Filed on Jan. 25, 2021, as Appl. No. 17/157,303.
Application 17/157,303 is a continuation of application No. 16/230,423, filed on Dec. 21, 2018, granted, now 10,901,903.
Prior Publication US 2021/0248078 A1, Aug. 12, 2021
Int. Cl. G06F 12/0866 (2016.01); G06F 3/06 (2006.01); G06F 12/02 (2006.01)
CPC G06F 12/0866 (2013.01) [G06F 3/0629 (2013.01); G06F 12/0246 (2013.01); G06F 12/0292 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method of operating a Universal Flash Storage (UFS)-compliant memory device, comprising:
maintaining a first portion of a flash transition layer (FTL) mapping table of the UFS-compliant memory device in a first location of the memory device;
saving write information received in UFS write requests from a host, the UFS write requests further including a respective first logical block address and a UFS group number field including a persistence flag;
saving the write information to a memory array of the UFS-compliant memory device;
saving mapping information including the respective first logical block address for respective write information to either the first location of the UFS-compliant memory device or a second location of the UFS-compliant memory device in response a state of the persistence flag;
wherein the second location is a persistent cache including volatile memory;
wherein mapping information for respective write information of memory requests having the persistence flag in a first state is saved to the second location;
wherein mapping information for respective write information of memory requests having the persistence flag in a second state is saved to the first location;
receiving a third command from a host, the third command including a size for the persistent cache; and
allocating a size of the persistent cache commensurate with the size for the persistent cache size of the third command.