Microchip Technology Inc.

Other

Microship Technology Incorporated

Kent D Hewitt

Donald S Gerber

Jeffrey A Shields

Samuel E Alexander

Randy L Yach

Richard J Fisher

Willem Smit

Gianpaolo Spadini

Bomy A Chen

David M Susak

Sonu Daryanani

Frederick J Bruwer

Mel Hymas

Jack Wong

Emile Van Rooyen

Traian Bontas

Leonard F French

Stephen V Drehobl

Jen-I Pi

David M Davies

Iulian Dumitru

Claudiu-Dumitru Nechifor

Daniel Alvarez

A memory array includes (a) multiple memory cells arranged into a plurality of bytes, (b) a separate word line connected to each byte, and (b) multiple shared source lines, each connected to at least two bytes, such that each byte in the array is addressable by a separate word line and by the shared source line. Due to this memory array architecture, a program operation on a first byte applies a shared source line voltage on a non-selected second byte (with an inhibit voltage applied to bit lines connected to the second byte), which creates a disturb condition that corresponds with a diagonal (or row) program disturb condition in a conventional memory array. The use of the shared source lines may reduce the required number of source line drivers, which reduces the overhead area of the memory array, and at same time, allow backward compatibility of traditional byte-alterable EEPROM.

Shared source line memory architecture for flash cell byte-alterable high endurance data memory

An electrically erasable programmable read only memory (EEPROM) cell may include a substrate including at least one active region, a floating gate adjacent the substrate, a write/erase gate defining a write/erase path for performing high voltage write and erase operations, and a read gate defining a read path for performing low voltage read operations, wherein the read path is distinct from the write/erase path. This allows for a smaller read gate oxide, thus allowing the cell size to be reduced. Further, the EEPROM cell may include two independently controllable read gates, thereby defining two independent transistors which allows better programming voltage isolation. This allows the memory array to be drawn using a common source instead of each column of EEPROM cells needing its own source line. This makes the array more scalable because the cell x-dimension would otherwise be limited by each column needing two metal 1 pitches.

EEPROM memory cell with low voltage read path and high voltage erase/write path

By arranging both a conductive and non-conductive resistive memory cell in a cross coupled arrangement to facilitate reading a data state the memory cells can have very small differences in their resistance values and still read correctly. This allows both of the memory cells' resistances to change over time and still have enough difference between their resistances to read the desired data state that was programmed. A pair of ReRAM or CBRAM resistive memory devices are configured as a one bit memory cell and used to store a single data bit wherein one of the resistive memory devices is in an ERASE condition and the other resistive memory devices of the pair is in a WRITE condition. Reading the resistance states of the resistive memory device pairs is accomplished without having to use a reference voltage or current since a trip-point is between the conductive states thereof.

Resistive random access memory (ReRAM) and conductive bridging random access memory (CBRAM) cross coupled fuse and read method and system

A method for programming and erasing an array of NMOS electrically erasable programmable read only memory (EEPROM) cells that minimizes bit disturbances and high voltage requirements for the memory array cells and supporting circuits. In addition, the array of N-channel memory cells may be separated into independently programmable memory segments by creating multiple, electrically isolated P-wells upon which the memory segments are fabricated. The multiple, electrically isolated P-wells may be created, for example, by p-n junction isolation or dielectric isolation.

Method of programming an array of NMOS EEPROM cells that minimizes bit disturbances and voltage withstand requirements for the memory array and supporting circuits

Method for programming and erasing an array of NMOS EEPROM cells that minimizes bit disturbances and voltage withstand requirements for the memory array and supporting circuits

An array of P-channel memory cells is separated into independently programmable memory segments by creating multiple, electrically isolated N-wells upon which the memory segments are fabricated. The methods for creating the multiple, electrically isolated N-wells include p-n junction isolation and dielectric isolation.

Independently programmable memory segments within a PMOS electrically erasable programmable read only memory array achieved by N-well separation and method therefor

A method of writing and selectively erasing bits in a selected group of memory cells that significantly reduces the likelihood of disturbing data stored in other, non-selected groups of memory cells is disclosed. The method varies the bias voltages applied to bit lines in unselected cells depending upon the selected or non-selected state of the cells. This reduces the voltage differential applied to the unselected cells, reducing the possibility of inadvertently causing unwanted changes in the amount of charge stored on the respective floating gates of the unselected cells. The method of the present invention improves electrical isolation between columns of cells without increasing the distance between the cells.

Programming method for a memory cell

A method of applying voltages to a memory cell, such as a P-channel EEPROM cell, and in particular to applying voltages to the cell during an erase operation of the cell is described. The method recognizes that during an erase, memory cells sharing deselected word lines are susceptible to a type of program disturb which is subtle and gradually causes corruption and loss of data over many programming cycles. The method of the present invention applies a voltage to deselected word lines, which is lower in magnitude than a programming voltage. This reduces the rate at which program disturb occurs, markedly increasing the number of programming cycles to which the deselected cells may be subjected before becoming susceptible to loss of data. The endurance of the memory array is thus significantly extended.

Method for minimizing program disturb in a memory cell

A time delay circuit that produces a constant delay and is independent of supply voltage. The time delay circuit has a current mirror circuit, a voltage shift circuit, an inverter and a capacitor. The inverter will trip at a predetermined voltage level. A capacitor is coupled to the current mirror circuit and to the inverter for generating a portion of the delay time. A voltage shift circuit is coupled to the inverter for approximately mirroring a voltage shift in the current mirror circuit thereby allowing the time delay circuit to be voltage independent.

Time delay circuit which is voltage independent

According to the present invention, there is provided an integrated circuit useful in an electronic encoding device having a voltage source, a user interface and a transmitter. In one embodiment the integrated circuit includes a wake-up circuit which generates a signal responsive to an input received from the user interface; power switching logic which provides power from the voltage source to a non-regulated power bus and a voltage regulating circuit, the power switching logic being responsive to the signal from the wake-up circuit; a regulated power bus in communication with the voltage regulating circuit; non-volatile memory in communication with the regulated power bus; encoder logic in communication with the regulated power bus, the encoder logic having output logic which provides a signal to the transmitter.

Integrated voltage regulating circuit useful in high voltage electronic

According to the present invention there is provided an encoder, which in one embodiment, includes a processing circuit which generates an output code according to an encoding algorithm, a counter circuit for incrementing a counter value such that only one bit of the counter value changes each time the counter value is incremented, a non-volatile memory for storing the counter value, and a transmitter which transmits the output code and the counter value. In another embodiment of the invention there is provided a method for use with an encoder having a processing circuit which generates an output code according to an encoding algorithm, a counter circuit for incrementing a counter value, a non-volatile memory for storing the counter value, and a transmitter which transmits the output code and the counter value. In one embodiment, the method includes the steps of incrementing the counter value such that only one bit is changed each time the counter is incremented. In still a further embodiment the method includes the steps of using a semaphore register and determining whether the semaphore register is set to 0.

Method and apparatus for electronic encoding and decoding

According to the present invention, a method is provided for reading data from non-volatile memory in an electronic encoding device such that unauthorized access to the data is prevented. In one embodiment, the method includes the steps of writing a first set of data to the non-volatile memory; generating a voltage detect signal during the writing, the voltage detect signal being representative of a source voltage applied to the non-volatile memory; determining whether the writing was successful by evaluating the voltage detect signal; and reading data from the non-volatile memory responsive to the determination.

Method and apparatus for preventing unauthorized access to nonvolatile

A sequential memory device having a read pipeline data structure for reading data from a bitline of a memory array of the device is disclosed. The read pipeline data structure includes at least one data path including a sense amp for sensing the logic level appearing on the bitline, a flip-flop for providing an output signal indicative of the data bits received on the bitline, and means for initializing the data path upon power up of the device such that the first data bit from the memory array is available for output from the device without the need and before the occurrence of a clock signal.

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Tempe, AZ, United States of America

Kent D Hewitt