# US 9,520,185 B2 · Method for performing memory access management, and associated memory device and controller thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,185 B2 - Document ID: US9520185B2 - Status: Granted - Kind: B2 - Application number: 14/956,410 - Filed: 2015-12-02 - Published: 2016-03-31 - Granted: 2016-12-13 - Earliest claimed: 2010-04-19 - Assignees: Silicon Motion, Inc. - Applicants: Silicon Motion Inc. - Inventors: Tsung-Chieh Yang; Hsiao-Te Chang; Wen-Long Wang - Web page: https://patentgrep.com/patent/US9520185B2 ## CPC - G11C 11/5642: {Sensing or reading circuits; Data output circuits} - G06F 3/0604: {Improving or facilitating administration, e.g. storage management} - G06F 3/0622: {in relation to access} - G06F 3/0629: {Configuration or reconfiguration of storage systems} - G06F 3/0638: {Organizing or formatting or addressing of data} - G06F 3/0679: {Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]} - G11C 11/5628: {Programming or writing circuits; Data input circuits} - G11C 16/08: Address circuits; Decoders; Word-line control circuits - G11C 16/26: Sensing or reading circuits; Data output circuits - G11C: STATIC STORES (semiconductor memory devices H10B) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A method for performing memory access includes: performing a plurality of sensing operations respectively corresponding to a plurality of different sensing voltages to generate a first digital value of a Flash cell of a Flash memory and a second digital value of the Flash cell of the Flash memory; using the first digital value and the second digital value to obtain soft information of a bit stored in the Flash cell; and using the soft information to perform soft decoding. ## Claims ### Claim 1 A method for performing memory access, comprising: performing a plurality of sensing operations respectively corresponding to a plurality of different sensing voltages to generate a first digital value of a Flash cell of a Flash memory and a second digital value of the Flash cell of the Flash memory; using the first digital value and the second digital value to obtain soft information of a bit stored in the Flash cell; and using the soft information to perform soft decoding. ### Claim 2 (depends on 1) The method of claim 1, wherein the first digital value and the second digital value are used to determine information of a same bit stored in the Flash cell, and a number of possible bit (s) of the Flash cell directly corresponds to a number of possible states of the Flash cell. ### Claim 3 (depends on 1) The method of claim 1, wherein the second digital value represents a candidate threshold voltage of the Flash cell and the soft information corresponds to a threshold voltage of the Flash cell. ### Claim 4 (depends on 3) The method of claim 3, further comprising: determining the threshold voltage of the Flash cell according to the candidate threshold voltage. ### Claim 5 (depends on 3) The method of claim 3, wherein the second digital value represents whether the candidate threshold voltage of the Flash cell is high or low; and the method further comprises: determining the threshold voltage of the Flash cell according to whether the candidate threshold voltage is high or low. ### Claim 6 (depends on 1) The method of claim 1, wherein the step of performing a plurality of sensing operations respectively corresponding to a plurality of different sensing voltages to generate a first digital value of a Flash cell of a Flash memory and a second digital value of the Flash cell of the Flash memory comprises: applying a first sensing voltage to the Flash cell; when current flows through the cell, applying a second sensing voltage which is less than the first sensing voltage; and when current does not flow through the cell, applying a second sensing voltage which is greater than the first sensing voltage. ### Claim 7 (depends on 1) The method of claim 1, wherein the second digital value comprises a plurality of second digital values, and each of the second digital values is generated according to another of the second digital values. ### Claim 8 (depends on 1) A controller of a memory device utilized for accessing a Flash memory which comprises a plurality of blocks, the controller comprising: a read only memory (ROM) arranged to store a program code; and a microprocessor arranged to execute the program code to control access to the Flash memory and manage the plurality of blocks, wherein under control of the microprocessor, the controller performs the steps of claim 1. ### Claim 9 A memory device, comprising: a Flash memory comprising a plurality of blocks; and a controller, for accessing the Flash memory, managing the plurality of blocks, and performing memory access management of data accessed by the controller, wherein the controller performs a plurality of sensing operations respectively corresponding to a plurality of different sensing voltages to generate a first digital value of a Flash cell of a Flash memory and a second digital value of the Flash cell of the Flash memory, uses the first digital value and the second digital value to obtain soft information of a bit stored in the Flash cell, and uses the soft information to perform soft decoding. ### Claim 10 (depends on 9) The memory device of claim 9, wherein the first digital value and the at least one second digital value are used for determining information of a same bit stored in the Flash cell, a number of possible bit (s) of the Flash cell directly corresponds to a number of possible states of the Flash cell. ### Claim 11 (depends on 10) The memory device of claim 10, wherein the second digital value represents a candidate threshold voltage of the Flash cell and the soft information corresponds to a threshold voltage of the Flash cell. ### Claim 12 (depends on 10) The memory device of claim 10, wherein the controller determines the threshold voltage of the Flash cell according to the candidate threshold voltage. ### Claim 13 (depends on 10) The memory device of claim 10, wherein the second digital value represents whether the candidate threshold voltage of the Flash cell is high or low; and the controller determines the threshold voltage of the Flash cell according to whether the candidate threshold voltage is high or low. ### Claim 14 (depends on 9) The memory device of claim 9, wherein the controller performs a plurality of sensing operations by applying a first sensing voltage to the Flash cell; when current flows through the cell, the controller applies a second sensing voltage which is less than the first sensing voltage; and when current does not flow through the cell, the controller applies a second sensing voltage which is greater than the first sensing voltage. ### Claim 15 (depends on 9) The memory device of claim 9, wherein the second digital value comprises a plurality of second digital values; and each of the second digital values is output by the Flash memory according to another of the second digital values.