Abstract: A circuit for biasing the bulk terminal of a first MOS transistor having a first terminal connected to a first line set to a first potential, and a second terminal connected to a second line set to a second potential. The biasing circuit includes a second and a third MOS transistors having first terminals connected respectively to the first line and to the second line, second terminals connected to the bulk terminal of the first MOS transistor, and control terminals connected respectively to the second and to the first line.

Abstract: A pulse programming method for a non-volatile memory device includes: addressing memory cells to be programmed within the device by selecting corresponding hierarchic decoder transistors; biasing the gate terminals of the memory cells; and programming the memory cells by applying a voltage pulse, regulated by a bias circuit, to the drain terminals of the memory cells. Advantageously, the programming method further comprises a step of precharging an internal node of the bias circuit before starting the programming step, the internal node being connected to a parasitic capacitance of the memory device.

Abstract: A voltage boost device includes a first boost stage and a second boost stage connected to an input terminal and to an output terminal, the output terminal supplying an output voltage higher than a supply voltage. The input terminal receives an operating condition signal having a first logic level representative of a standby operating state and a second logic level representative of an active operation state. The first boost stage is enabled in presence of the second logic level of the operating condition signal, and is disabled in presence of the first logic level of the operating condition signal; the second boost stage is controlled in a first operating condition in presence of the first logic level of the operating condition signal, and is controlled in a second operating condition in presence of the second logic level of the operating condition signal.

Abstract: The switch circuit receives a first supply voltage and a second supply voltage different from each other; a control input receiving a control signal that may be switched between the first supply voltage and ground; a driving inverter stage supplied by the second supply voltage and defining the output of the circuit; a feedback inverter stage supplied by the second supply voltage and including a top transistor and a bottom transistor defining an intermediate node and having respective control terminals. The control terminal of the top transistor is connected to the output node, the control terminal of the bottom transistor is connected to the control input, and the intermediate node is connected to the input of the driving inverter stage. An activation element helps switching of the intermediate node from the second supply voltage to ground; current limiting transistors are arranged in the inverter stages to limit the current flowing during switching and to reduce the consumption of the circuit.

Abstract: A circuit for reading a non-volatile memory cell has an output terminal for providing an output current, and a control terminal for receiving a voltage for controlling the output current. The reading circuit includes a feedback circuit which can be connected electrically to the output terminal and to the control terminal to generate the control voltage from a reference signal and from the output current. The feedback circuit also includes a current-amplification circuit having a first terminal for receiving a current-error signal derived from the reference signal and from the output current, and a second terminal for supplying an amplified current.

Abstract: Described herein is a nonvolatile memory comprising a memory array organized according to global word lines and local word lines; a global row decoder; a local row decoder; a first supply stage for supplying the global row decoder; and a second supply stage for supplying the local row decoder; and a third supply stage for biasing the drain and source terminals of the memory cells of the memory array. Each of the supply stages comprises a respective resistive divider formed by a plurality of series-connected resistors, and a plurality of pass-gate CMOS switches each connected in parallel to a respective resistor. The nonvolatile memory further comprises a control circuit for controlling the pass-gate CMOS switches of the supply stages, and a switching circuit for selectively connecting the supply input of the control circuit to the output of the second supply stage during reading and programming of the memory, and to the output of the third supply stage during erasing of the memory.

Abstract: A voltage generator formed of a charge circuit and a discharge circuit having a common programmable voltage divider with variable resistance; the programmable voltage divider including a plurality of resistors arranged in series and selectively connectable to define alternatively a step-wise increasing program voltage and a fixed verify voltage. The charge circuit formed of a voltage regulator supplying at the output the precise voltage value determined by the programmable voltage divider, and the discharge circuit intervening when the output voltage must be switched in a controlled manner from a higher value to a lower value.

Abstract: A voltage regulator having a comparator with an output terminal that is the output of the regulator, terminals for connection to a voltage supply, a source of a reference voltage connected to an input terminal of the comparator, and a feedback circuit connected between the output terminal and the other input terminal of the comparator. To prevent transients upon the transition from the standby state to the active state, there is provided a second reference-voltage source that provides a reference voltage substantially equal to that of the first source, a switch for connecting the second source to the other input terminal of the comparator, and a control circuit that can activate the supply of the regulator and can close the switch for a predetermined period of time when the supply of the regulator is activated.

Abstract: A non-volatile memory device with configurable row redundancy includes a non-volatile memory having a matrix of memory cells and a matrix of redundant memory cells, both organized into rows and columns. The memory device also includes row and column decoding circuits; read and modify circuits for reading and modifying data stored in the memory cells; and at least one associative memory matrix, also organized into rows and columns, able to store the addresses of faulty rows, and control circuits for controlling the associative memory matrix. The memory device further includes a circuit for recognizing and comparing selected row addresses with faulty row addresses contained in the associative memory matrix, such as to produce de-selection of the faulty row and selection of the corresponding redundant cell row in the event of a valid recognition; and a configuration register, also comprising a matrix of non-volatile memory cells, and associated control circuits.

Abstract: A charge pump voltage booster circuit for generating, from a first voltage supplied at the input to the circuit, an output voltage with an absolute value that is higher than the first voltage, comprises at least one stage having a charge pass element and a charge storage capacitor with a first plate connected to an output of the charge pass element and a second plate controlled by a square-wave control signal of period varying between a reference voltage and the first voltage, supplied to the second plate of the capacitor by means of a driver circuit comprising a pull-up transistor and a pull-down transistor connected in series between the first voltage and the reference voltage. Means of overdriving at least one of the said transistors, either the pull-up transistor or the pull-down transistor, supply to the said at least one transistor a firing control voltage that has a higher absolute value than the first voltage.

Abstract: The multilevel memory device has a memory section containing cells that can be programmed with a predetermined number of levels greater than two, i.e., a multilevel array, and a memory section containing cells that can be programmed with two levels, i.e., a bilevel array. The multilevel array is used for storing high-density data, for which speed of reading is not essential, for example for storing the operation code of the system including the memory device. On the other hand, the bilevel array is used for storing data for which high speed and reliability of reading is essential, such as the BIOS of personal computers, and the data to be stored in a cache memory. The circuitry parts dedicated to programming, writing of test instructions, and all the functions necessary for the operation of the memory device, can be common to both arrays.

Abstract: The data management method applies to a multilevel nonvolatile memory device having a memory array formed by a plurality of memory cells. Each of the memory cells stores a number of bits that is not an integer power of two, for example three. In this way, one data byte is stored in a non-integer number of memory cells. The managing method includes storing, in a same clock cycle, a data word formed by a plurality of bytes, by programming a preset number of adjacent memory cells. Reading is performed by reading, in a same clock cycle, the stored data word.

Abstract: A charge pump voltage booster circuit for generating, from a first voltage supplied at the input to the circuit, an output voltage with an absolute value that is higher than the first voltage, comprises at least one stage having a charge pass element and a charge storage capacitor with a first plate connected to an output of the charge pass element and a second plate controlled by a square-wave control signal of period varying between a reference voltage and the first voltage, supplied to the second plate of the capacitor by means of a driver circuit comprising a pull-up transistor and a pull-down transistor connected in series between the first voltage and the reference voltage. Means of overdriving at least one of the said transistors, either the pull-up transistor or the pull-down transistor, supply to the said at least one transistor a firing control voltage that has a higher absolute value than the first voltage.

Abstract: A multilevel nonvolatile memory includes a supply line supplying a supply voltage, a voltage boosting circuit supplying a boosted voltage, higher than the supply voltage, a boosted line connected to the voltage boosting circuit and a reading circuit including at least one comparator. The comparator includes a first and a second input, a first and a second output, at least one amplification stage connected to the boosted line, and a boosted line latch stage connected to the supply line.

Abstract: The memory device comprises a memory array having an organization of the type comprising global word lines and local word lines, a global row decoder addressing the global word lines, a local row decoder addressing the local word lines, a global power supply stage supplying the global row decoder, and a local power supply stage supplying the local row decoder.

Abstract: A semiconductor memory such as a flash memory, which comprises at least one two-dimensional array of memory cells with a plurality of rows and columns of memory cells grouped in a plurality of packets. The memory cells belonging to the columns of each packet are formed in a respective semiconductor region with a first type of conductivity, this region being distinct from the semiconductor regions with the first type of conductivity in which the memory cells belonging to the columns of the remaining packets are formed. The semiconductor regions with the first type of conductivity divide the set of memory cells belonging to each row into a plurality of subsets of memory cells that constitute elemental memory units which can be modified individually. Thus memory units of very small dimensions can be erased individually, without excessive overhead in terms of area.

Abstract: The row decoder includes, for each word line of the memory, a respective biasing circuit receiving at the input a row selection signal switching, in preset operating conditions, between a supply voltage and a ground voltage and supplying at the output a biasing signal for the respective word line switching between a first operating voltage, in turn switching at least between the supply voltage and a programming voltage higher than the supply voltage, and a second operating voltage, in turn switching at least between the ground voltage and an erase voltage lower than the ground voltage. Each biasing circuit includes a level translator circuit receiving at the input the row selection signal and supplying as output a control signal switching between the first and the second operating voltages and an output driver circuit receiving as input the control signal and supplying at the output the biasing signal.

Abstract: The memory array comprises a plurality of cells, grouped together in sectors and arranged in sector rows and columns, and has both hierarchical row decoding and hierarchical column decoding. Global word lines are connected to at least two word lines in each sector, through local row decoders; global bit lines are connected to at least two local bit lines in each sector, through local column decoders. The global column decoder is arranged in the center of the memory array, and separates from each other an upper half and a lower half of the memory array. Sense amplifiers are also arranged in the middle of the array, thus saving space. This architecture also provides lesser stress of the cells, better reliability, and better production performance. In addition, each sector is completely disconnected from the remaining sectors, and only the faulty row or column of a single sector should be doubled.

Abstract: A circuit device structured to enable a hierarchic form of row decoding in semiconductor memory devices of the non-volatile type and including at least one matrix of memory cells with sectors organized into columns, wherein each sector has a specific group of local word lines individually connected to a main word line running through all of the matrix sectors which have rows in common is presented. The device includes a first transistor of the PMOS type having its conduction terminals connected, one to the main word line and the other to the local word line, and a second transistor of the NMOS type having its conduction terminals connected, one to the local word line and the other to a reference voltage.

Abstract: A non-volatile memory device with configurable row redundancy includes a non-volatile memory having a matrix of memory cells and a matrix of redundant memory cells, both organized into rows and columns. The memory device also includes row and column decoding circuits; read and modify circuits for reading and modifying data stored in the memory cells; and at least one associative memory matrix, also organized into rows and columns, able to store the addresses of faulty rows, and control circuits for controlling the associative memory matrix. The memory device further includes a circuit for recognizing and comparing selected row addresses with faulty row addresses contained in the associative memory matrix, such as to produce de-selection of the faulty row and selection of the corresponding redundant cell row in the event of a valid recognition; and a configuration register, also comprising a matrix of non-volatile memory cells, and associated control circuits.