Abstract:
A method for the parallel programming of memory words in electrically programmable non-volatile semiconductor memory devices comprising at least one matrix of floating gate memory cells with corresponding drain terminals heading columns or bit lines of the matrix which are supplied during the single word programming stage with a drain voltage which is boosted with respect to a supply voltage (Vcc). During the parallel programming stage the supply voltage is used as a drain voltage. Switching is provided between the drain supply using the boosted drain voltage and the supply voltage (Vcc) during the transient between single word programming and parallel programming.
Abstract:
A method for setting the threshold voltage of a reference memory cell (RMC) of a memory device is described, the reference memory cell (RMC) being used as a reference current generator for generating a reference current which is compared by a sensing circuit (1,2,3) of the memory device with currents sunk by memory cells to be sensed, belonging to a memory matrix (MM) of the memory device. The method comprises a first step in which the reference memory cell (RMC) is submitted to a change in its threshold voltage, and a second step in which the threshold voltage of the reference memory cell (RMC) is verified. The second step provides for performing a sensing of the reference memory cell (RMC) using a memory cell (MC) with known threshold voltage (V TUV ) belonging to the memory matrix (MM) as a reference current generator for generating a current (IC) which is compared by the sensing circuit (1,2,3) with the current (IR) sunk by the reference memory cell (RMC).
Abstract:
A high-resolution digital filter of a type which comprises a memory structure receiving as input a sampled digital signal, and an adder chain with delay blocks therebetween, the adders being connected to memory outputs to convert the input signal into an output signal having predetermined frequency response characteristics, has the memory structure made up of at least one pair of non-volatile memories (3,4) being input each one portion (x(n)₁,x(n)₂) only of the sampled signal.
Abstract:
The invention relates to a programming method and device for detecting an error and inhibiting writing into a memory. The invention provides for the inclusion, in the standard programming method, of a checking step for interrupting the programming procedure and generating an error signal detecting the attempted overwriting of a "0" with a "1". The checking step of the inventive programming method provides for an initial comparison between the contents of a plurality of bits being programmed and a corresponding plurality of bits to be written in, the generation of an error signal upon detection of homolog pairs with a value of "one", and the interruption of the byte programming procedure to prevent a "1" from being written over a "0".
Abstract:
The invention relates to a row decoding circuit (1) for an electrically programmable and erasable semiconductor non-volatile storage device of the type which comprises a matrix (2) of memory cells laid out as cell rows (WL) and columns and is divided into sectors, said circuit being input row decode signals (p,ly,lx,ls) and supply voltages (Vpcxs, pgate) in order to drive an output stage (8) incorporating a complementary pair of high-voltage MOS transistors (M15,M13) of the pull-up and pull-down type, respectively, which are connected to form an output terminal (U) connected to the rows (WL) of one sector of the matrix (2), characterized in that a MOS transistor (M9) of the P-channel depletion type with enhanced gate oxide is provided between the output terminal (U) and the pull-down transistor (M13). The control terminal of the depletion transistor (M9) forms a further input (H) of the circuit (1).
Abstract:
A fast adder chain, of a type intended for adding together at least one pair of digital words (X,Y) and comprising a plurality of cascaded adder blocks, has in each block (2) computation means (HA,FA) for obtaining the pseudosum of said pair of digital words (X,Y) and means (10,11) for storing and transmitting the pseudosum (SOMi) to the next block and the pseudocarry (Ci) from the computation to the chain end.