1. A data storage method for error detections and corrections in a memory organized to read and write words of a first number (m) of bits and possibly to modify a portion only of such a word, comprising the steps of: associating an error detection and correction code with a group of a second number (k≧1) of words; and at each partial writing in the word group: calculating a new code of the modified word group, implementing a checking operation and, if an error appears, making an error correction of the modified word and/or of the new code.