Write method for differential resistive memories

A method for writing a data word to a resistive memory consisting of 2T2R differential cells each comprising first and second sets of a resistor (R) and a selection transistor (T), the method comprising steps of:

• generating an initial codeword from initial data bits and from check bits generated from the data word, and initializing a counter for counting a number of programming operations, the number of programming operations corresponding to a maximum number of programming operations for said word in a group of selected differential cells;
• programming this initial codeword in the resistive memory in 1T1R mode, by selecting the first 1T1R sets of the selected differential cells, and then performing a 1T1 R check read operation and incrementing or decrementing the counter for counting the number of programming operations;
• repeating the previous step for as long as all of the bits of the initial codeword have not been correctly programmed and the maximum number of programming operations has not been reached;
• inverting the initial codeword and reinitializing the counter for counting the number of programming operations;
• programming the initial codeword inverted in the previous step in the resistive memory in 1T1R mode, by selecting the second 1T1R sets of the selected differential cells, and then performing a 1T1R check read operation and incrementing or decrementing the counter for counting the number of programming operations;
• repeating the previous step for as long as all of the bits of the inverted initial codeword have not been correctly programmed and the maximum number of programming operations has not been reached;
• performing a check read operation in 2T2R differential mode on the selected differential cells and checking at least that the read data correspond to said initial data;
• and, depending on the result of the check,
• terminating the write method or
• signalling an error in the write method.