selector 8 is positioned to enable the data generator 12 to control the column supply circuit 9 to carry out the pre erasure programming algorithm the state machine controls the data generator 12 so that at output it gives a logic value corresponding to the programmed state of the cells the state machine furthermore controls the address generator so that it places the row and column decoders in a state of communication with an address counter not shown initially at zero the state machine 2 then activates a programming cycle which first of all commands the supply circuit 6 to give a programming pulse to the gates then as with the writing the data elements are read and compared to determine whether a new programming pulse is necessary if this is the case a new programming pulse is given the programming cycles are thus repeated until the comparator 10 no longer detects any difference the state machine 3 then gives the address generator 11 an incrementation command signal so as to increase the address applied to the decoder 5 and 7 by one unit the state machine then activates new programming cycles in the manner indicated here above at the.