Abstract: Data is written into a non-volatile semiconductor memory using one of at least four steps. A first step is executed if the final states of both the first bit (B1) and the second bit (B2) coincide with their respective initial states and includes maintaining the initial states of the first bit (B1) and the second bit (B2). A second step is executed if both the first bit (B1) and the second bit (B2) have erased final states and the initial states of both the first bit (B1) and the second bit (B2) were not erased and includes erasing both the first bit (B1) and the second bit (B2). A third step is executed if neither the first bit (B1) nor the second bit (B2) is to be changed from a programmed initial state to an erased final state and includes programming the first bit (B1) if the first bit (B1) is to be changed from an erased initial state to a programmed final state, and/or programming the second bit (B2) if the second bit (B2) is to be changed from an erased initial state to a programmed final state.

Abstract: A circuit for reading a semiconductor memory device includes at least one global circuit for generating a global reference signal for a respective plurality of cell-reading circuits disposed locally in the memory device. The circuit includes at least one circuit for replicating the reference signal locally in order to generate a local reference signal to be supplied to at least one respective cell-reading circuit.