Method for Reading Data Stored in a Flash Memory According to a Threshold Voltage Distribution and Memory Controller and System Thereof

A method for reading data stored in a flash memory, wherein the flash memory comprises a plurality of memory cells and each memory cell has a particular threshold voltage, the method comprising:

• reading a part of the memory cells of the flash memory by a first control gate voltage;
• detecting error bits of the memory cells;
• correcting the error bits of the memory cell by reading the flash memory continuously;
• obtaining the number of first bit flipping by reading the memory cells;
• obtaining a first voltage characteristic of the memory cells based on the number of first bit flipping;
• averaging the first voltage characteristic for obtaining a second voltage characteristic;
• and
• reading a part of the flash memory again by using the second voltage characteristic;
• wherein the first set of memory cells comprises at least a part of the memory cells of the second set.

A system for reading data stored in a flash memory, wherein the flash memory comprises a plurality of memory cells and each memory cell has a particular threshold voltage, the system comprising:

• a control logic for reading a part of the memory cells of the flash memory by using a first control gate voltage;
• a detector for detecting error bits of the memory cells;
• a corrector for correcting the error bits of the memory cell by reading the flash memory continuously;
• wherein the control logic further obtains the number of first bit flipping by reading the memory cells, obtains a first voltage characteristic of the memory cells based on the number of first bit flipping, averages the first voltage characteristic for obtaining a second voltage characteristic, and reads a part of the flash memory again by using the second voltage characteristic;
• and
• wherein the first set of memory cells comprises at least a part of the memory cells of the second set.