A programmable error correcting device is disclosed. The programmable error correcting device includes a controller for receiving information about a length of a codeword, an error correcting capacity, whether of not a shortened codeword mode is supported and a total byte number of burst data and outputting a control signal; a preprocessor for dividing input information data by a length of information byte in a codeword and outputting the divided input information data with a valid data indicating signal in response to the control signal input from the controller for an error correcting coding; and a coder for deciding a structure for an error correcting encoding according to the control signal inputted from the controller and performing an error correcting encoding on information data inputted from the preprocessor according to the decided structure.