National Semiconductor Corporation

Stmicroelectronics Gmbh

Pavel Poplevine

Andrew J Franklin

Alexander Kalnitsky

Albert M Bergemont

Hengyang James Lin

Hengyang (James) Lin

Ernes Ho

Annie-Li-Keow Lum

Yuri Mirgorodski

Umer Ahmed Khan

Peter J Hopper

James Thomas Doyle

Wai Cheong Chan

Elroy M Lucero

Gordon L Mortensen

Andrew Cao

Hsing-Chien Roy Liu

Murali Krishna Varadarajula

Daniel J Lucero

Vladislav Vashchenko

Mark Willam Poulter

Jasopin Lee

Weipeng Zhang

Derek Tao

Annie-Li-Koow Lum

Anti-pirate circuitry is provided for combating the theft of intellectual property contained with semiconductor integrated circuits. The anti-pirate circuit includes a unique number generator that provides a multi-bit die ID data string that is unique to the integrated circuit associated with the anti-pirate circuit. One time programmable (OTP) EPROM circuitry reads the die ID data string at wafer sort and writes the data content to nonvolatile memory. During a subsequent verification cycle, ID comparator circuitry compares the data string provided by the unique number generator to the stored contents of the nonvolatile memory. If the comparison results in a mismatch between more than a predefined number of bits, then the integrated circuit associated with the anti-pirate circuit is not enabled for operation.

Anti-pirate circuit for protection against commercial integrated circuit pirates

A non-volatile memory cell includes NMOS programming, read, erase, and control transistors having gate electrodes connected to a storage node. The erase and control transistors have interconnected source, drain, and bulk electrodes. The cell is programmed by setting source, drain, bulk, and gate electrodes of all transistors to a positive voltage. An inhibiting voltage is applied to source, drain, and bulk electrodes of the read transistor, while setting source and drain electrodes of the programming transistor to the positive voltage and the bulk electrode of the programming transistor to the positive voltage or the inhibiting voltage. Source, drain, and bulk electrodes of the control transistor are then ramped to a negative control voltage while ramping source, drain, and bulk electrodes of the erase transistor to a negative erase voltage and then back to the positive voltage. Source, drain. bulk, and gate electrodes of the programming, erase, and control transistors are then returned to the positive voltage, while setting the source, drain, and bulk electrodes of the read transistor to the inhibiting voltage.

All-NMOS 4-transistor non-volatile memory cell

A non-volatile memory (NVM) cell comprises an NMOS control transistor having commonly-connected source, drain and bulk region electrodes and a gate electrode connected to a storage node; a PMOS erase transistor having commonly-connected source, drain and bulk region electrodes and a gate electrode connected to the storage node; an NMOS data transistor having source, drain and bulk region electrodes and a gate electrode connected to the storage node, the bulk region electrode being connected to a common bulk node; the first NMOS pass gate transistor having a source electrode connected to the drain electrode of the NMOS data transistor, a drain electrode, a bulk region electrode connected to the common bulk node, and a gate electrode; and a second NMOS pass gate transistor having a drain electrode connected to the source electrode of the NMOS data transistor, a source electrode, a bulk region electrode connected to the common bulk node, and a gate electrode.

5-transistor non-volatile memory cell

A non-volatile memory (NVM) cell structure comprises a PMOS program transistor having source, drain and bulk region electrodes and a gate electrode that is connected to a data storage node; an NMOS control transistor having source, drain and bulk region electrodes that are commonly-connected to receive a control voltage and a gate electrode that is connected to the data storage node; a PMOS erase transistor having source, drain and bulk region electrodes that are commonly-connected to receive an erase voltage and a gate electrode that is connected to the data storage node; and an NMOS read transistor having source, drain and bulk region electrodes and a gate electrode connected to the data storage node.

4-transistor non-volatile memory cell with PMOS-NMOS-PMOS-NMOS structure

An NVM cell design enables direct reading of cell output voltage to determine data stored in the cell, while providing low current consumption and a simple program sequence that utilizes reverse Fowler-Nordheim tunneling.

Method of directly reading output voltage to determine data stored in a non-volatile memory cell

A 4-transistor non-volatile memory (NVM) cell includes a static random access memory (SRAM) cell structure. The NVM cell utilizes a reverse Fowler-Nordheim tunneling programming technique that, in combination with the SRAM cell structure, allows an entire array to be programmed at one cycle. Equalize transistors are utilized to obtain more uniform voltage on the floating gates after an erase operation. Utilization of decoupling pas gates during a read operation results in more charge difference on floating gates of programmed and erased cells.

Non-volatile memory cell with improved programming technique with decoupling pass gates and equalize transistors

A method of making a non-volatile memory (NVM) cell structure includes the formation of a first NVM cell, a second NVM cell and an SRAM cell that includes first and second data nodes. A first pass gate structure is connected between the first NVM cell and the first data node of the SRAM cell, the first pass gate structure being responsive to first and second states of a first pass gate signal to respectively couple and decouple the first NVM cell and the SRAM cell. A first equalize structure is formed to connect the first pass gate structure and the first NVM cell and is responsive to a first equalize signal to connect the first NVM cell to ground. A second pass gate structure is connected between the second NVM cell and the second data node of the SRAM cell, the second pass gate structure being responsive to first and second states of a second pass gate signal to respectively couple and decouple the second NVM cell and the SRAM cell. A second equalize structure is connected between the second pass gate structure and the second NVM cell, the second equalize structure being responsive to a second equalize signal to connect the second NVM cell to ground. Appropriate biasing conditions are applied to the NVM cell structure to implement program/operations.

Method of making a non-volatile memory (NVM) cell structure and program biasing techniques for the NVM cell structure

A single 4-transistor non-volatile memory (NVM) cell includes a shared static random access memory cell. The NVM cell utilizes a reverse Fowler-Nordheim tunneling programming technique that, in combination with the shared SRAM cell structure, allows an entire cell array to be programmed at two cycles. A single NVM cell approach with shared SRAM allows a 50% area reduction with an insignificant increase in program time.

Non-volatile memory cell with improved programming technique and density

In a SRAM structure, space and power saving is achieved by providing row and column select lines to select a specific bit cell, and reducing the number of bit lines in the structure used for writing to and reading from the bit cells. The number of bit lines is reduced by sharing bit lines of adjacent bit cells. Furthermore, in order to achieve power saving, the load on the row select lines is reduced by sharing the pass gates between adjacent bit cells that are used to control precharging, reading from and writing to the bit cells.

Bit line sharing and word line load reduction for low AC power SRAM architecture

A non-volatile memory (NVM) cell splits its basic functions, i.e. program, erase, read and control, among a four PMOS transistor structure, allowing independent optimization of each cell function. The cell structure also includes an embedded static random access memory (SRAM) cell that utilizes a latch structure to preprogram data to be written to the cell and a plurality of cascoded NMOS pass gates. The cell structure reduces total programming time and provides the flexibility of programming the entire cell array simultaneously or one row or sector of the array at a time.

Method of hot electron injection programming of a non-volatile memory (NVM) cell array in a single cycle

The supply voltage of a memory system is adjusted in response to changes in the frequency of the clock signal. The memory system measures a time from when data becomes valid on the output of a memory to the next clock edge to determine a timing value. When the clock frequency changes from a first frequency to a second frequency, the timing value changes from a first value to a second value. The magnitude of the supply voltage is changed to return the timing value to the first value.

Closed-loop, supply-adjusted ROM memory circuit

A non-volatile memory (NVM) cell splits its basic function, i.e. program, erase, read and control, among a four PMOS transistor structure, allowing independent optimization of each function. The cell structure also includes an embedded static random access memory (SRAM) cell that utilizes a latch structure to preprogram data to be written to the cell. The programming method for the cell utilizes a reverse Fowler-Nordheim tunneling mechanism with a very small programming current, allowing an entire NVM array to be programmed at one cycle.

Non-volatile memory cell with improved programming technique

In accordance with a method of programming an NVM array that includes 4-transistor PMOS non-volatile memory (NVM) cells having commonly connected floating gates, for all the cell's in the array that are to be programmed, all the electrodes of the cell are grounded. Then, an inhibiting voltage Vn is applied to the bulk-connected source region Vr of the cell's read transistor Pr, to the commonly connected drain, bulk and source regions Ve of the cell's erase transistor Pe, and to the drain region Dr of the read transistor Pr. The source region Vp and the drain region Dp of the cell's programming transistor Pw are grounded. The bulk Vnw of the programming transistor Pw is optional; it can be grounded or remain at the inhibiting voltage Vn. For all cells in the NVM array that are not selected for programming, the inhibiting voltage Vn is applied to Vr, Ve and Dr and is also applied to Vp, Dp and Vnw. The control gate voltage Vc of the cell's control transistor Pc is then swept from 0V to a maximum programming voltage Vcmax in a programming time Tprog. The control gate voltage Vc is then ramped down from the maximum programming voltage Vcmax to 0V. All electrodes of the cell and the inhibiting voltage Vn are then returned to ground.

Reverse fowler-nordheim tunneling programming for non-volatile memory cell

In a ROM structure, power consumption is reduced by providing for pre-discharging of only the bit line corresponding to the memory location that is being read. Column select lines are coupled to logic to switch in a pre-discharging circuit prior to reading, and to disconnect, from the pre-discharging circuit during reading, only the bit line corresponding to the memory location being read.

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Foster City, CA, United States of America

Pavel Poplevine