A semiconductor memory includes a first memory cell configured to be set with a first threshold voltage, the first threshold voltage being one of different threshold voltage levels, a second memory cell configured to be set with a second threshold voltage, the second threshold voltage being one of different threshold voltage levels, a first word line coupled to the first memory cell, a second word line coupled to the second memory cell, and a controller configured to read data of one of different bits based on a combination of the first threshold voltage of the first memory cell and the second threshold voltage of the second memory cell.