A semiconductor device is provided to extract information required for parity bit generation in response to a continuous decision signal or data masking information, thereby preventing a writing error during continuous writing actions. A memory cell array(201) stores data and parity data. A continuous writing decider(280) decides on identity of a column address in case of a continuous inputting action of a writing command, and generates a continuous decision signal. A parity generator(270) controls generation and output of the current parity data by using previous data and change data in response to the continuous decision signal. The parity generator controls generation and output of the current parity data in response to the continuous decision signal and data masking information.
