US 12,189,959 B2
Memory device with compressed soft information and associated control method
Tsung-Chieh Yang, Hsinchu (TW)
Assigned to Silicon Motion, Inc., Hsinchu County (TW)
Filed by Silicon Motion, Inc., Hsinchu County (TW)
Filed on Mar. 30, 2023, as Appl. No. 18/129,028.
Prior Publication US 2024/0329845 A1, Oct. 3, 2024
Int. Cl. G06F 3/06 (2006.01); H03M 13/45 (2006.01); G11C 29/52 (2006.01); H03M 13/00 (2006.01); H03M 13/11 (2006.01)
CPC G06F 3/0613 (2013.01) [G06F 3/0659 (2013.01); G06F 3/0679 (2013.01); H03M 13/45 (2013.01); G06F 2212/401 (2013.01); G11C 29/52 (2013.01); H03M 13/1108 (2013.01); H03M 13/1111 (2013.01); H03M 13/6312 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A control method of a flash memory controller, wherein the flash memory controller is configured to access a flash memory module, the flash memory module comprises at least one flash memory chip, each flash memory chip comprises a plurality of blocks, each block comprises a plurality of pages, and the control method comprises:
sending a first read command to the flash memory module, wherein the first read command requests data of a page of the flash memory module;
receiving first readout information from the flash memory module in response to the first read command;
decoding the first readout information;
in response to a condition that the first readout information fails to be decoded, estimating a number of error bits of the first readout information; sending a second read command to the flash memory module, wherein the second read command requests soft information of the page of the flash memory module, and the second read command comprises a compression mode indicator; wherein if the number of error bits of the first readout information is greater than a threshold value, sending the second read command with the compression mode indicator to the flash memory module; and if the number of error bits of the first readout information is not greater than a threshold value, sending the second read command with a non-compression mode indicator to the flash memory module;
for the second read command with the non-compression mode indicator to the flash memory module: receiving second readout information from the flash memory module in response to the second read command, wherein the second readout information comprises soft information; and performing a soft decoding method to decode the first readout information by using the soft information;
for the second read command with the compression mode indicator to the flash memory module:
receiving the second readout information from the flash memory module in response to the second read command, wherein the second readout information comprises a compressed soft information generated by compressing the soft information;
decompressing the compressed soft information to generate the soft information; and
performing the soft decoding method to decode the first readout information by using the soft information.