FLASH MEMORY, FLASH MEMORY SYSTEM AND OPERATING METHOD OF THE SAME

摘要

A flash memory, a flash memory device, and an operation method thereof are disclosed. The operation method of the flash memory according to an embodiment comprises the steps of: individually counting the number of memory cells including threshold voltage included in a first threshold voltage area defined by a first reference deduction voltage for closely located threshold voltage distribution and a first search deduction voltage including first voltage difference from the first reference deduction voltage and in a second threshold voltage area defined by the first reference deduction voltage and a second search deduction voltage including second voltage difference from the first reference deduction voltage; and setting a first optimal deduction voltage by reflecting a result value generated by calculating a first control parameter in the number difference of the memory cells including the threshold voltage included in the first and the second threshold voltage areas to the first reference deduction voltage.