Patent ID: 9117536
Filing Date: 2015-08-25
Classification: G11C

Abstract:
1. A method of operating a non-volatile memory device, the method comprising: employing a voltage generator to apply first and second read voltages to a first word line of the memory device to perform a read operation; counting first memory cells of the memory device each having a threshold voltage belonging to a first voltage range between the first read voltage and the second read voltage; employing the voltage generator to apply a third read voltage to the first word line sequentially after applying the second read voltage to count second memory cells of the memory device each having a threshold voltage belonging to a second voltage range between the second read voltage and the third read voltage; comparing a number of the first memory cells counted and a number of the second memory cells counted; determining a fourth read voltage based on a result of the comparing; and employing the voltage generator to apply the fourth read voltage to the first word line sequentially after applying the third read voltage.