A semiconductor memory device comprises a memory unit having a first and a second port and including plural banks; a bank address conversion circuit operative to convert a first bank address fed from external into a second bank address different from the first bank address and operative to supply the first bank address to one of the first and second ports and supply the second bank address to the other of the first and second ports; and a write data conversion circuit operative to convert input data fed from external into write data different from the input data and operative to supply the input data to one of the first and second ports and supply the converted write data to the other of the first and second ports.