Abstract: A four-phase charge pump circuit suitable for use on integrated circuits, such as flash memory devices, includes circuitry that drives charge pump nodes in two components separated by a time delay. The two components can be triggered by edges from the clocks that control the timing of the charge pump. Driving the charge pump nodes in two components separated by a delay decreases the peak current of the charge pump and improves noise characteristics of a voltage supply or ground line connected to the charge pump.

Abstract: A four-phase charge pump circuit suitable for use on integrated circuits, such as flash memory devices, includes circuitry that drives charge pump nodes in two components separated by a time delay. The two components can be triggered by edges from the clocks that control the timing of the charge pump. Driving the charge pump nodes in two components separated by a delay decreases the peak current of the charge pump and improves noise characteristics of a voltage supply or ground line connected to the charge pump.

Abstract: A method and an integrated circuit for performing a soft program after erase provides efficient convergence of over-erased floating gate memory cells disposed in bit lines. The soft program is applied to successive subject bit lines. The BLISP method includes selection of a selected bit line and applying the soft program to a subject bit line corresponding to the selected bit line. For integrated circuits having no defective bit lines, the subject bit lines comprise the selected bit lines. The BLISP method is adapted for low current consumption compared to bulk soft programming methods. In some embodiments, the integrated circuit includes defective bit lines. For these integrated circuits, the selection of the selected bit line includes indicating a bit line type corresponding to the selected bit line. The defective bit lines are logically replaced by redundant bit lines so that the soft program is applied to conforming selected bit lines and redundant bit lines corresponding to defective bit lines.

Abstract: An improved word line boost circuit suitable for use on integrated circuits such as flash memory devices includes a two step boosting circuit with a floating circuit node. A first circuit provides an initial boost of the output voltage from a precharged voltage. Part of the first circuit is floated, lessening a load on a second circuit. Then, the second circuit provides a second boost of the output voltage with increased power efficiency. A time delay separates the onset of the second boosting operation from the onset of the first boosting operation so as to define a two-step boost.

Abstract: A method increases endurance of an array of memory cells which have an endurance specified according to the number of change cycles that the memory cell can endure within a performance tolerance. The method is based on arranging the array into a plurality of sectors, and assigning a subset of addresses for storage of data structure expected to change a number of times that is sufficient to exceed the specified endurance of the memory cell in the array. A record is maintained indicating one of the plurality of sectors as a current sector, directing accesses using the subset of addresses to the current sector, counting changes executed to memory cells identified by the subset of addresses for the current sector, and changing the current sector to another one of the plurality of sectors when the count of changes exceeds the threshold.

Abstract: An improved word line boost circuit suitable for use on integrated circuits such as flash memory devices includes a two step boosting circuit with a floating circuit node. A first circuit provides an initial boost of the output voltage from a precharged voltage. Part of the first circuit is floated, lessening a load on a second circuit. Then, the second circuit provides a second boost of the output voltage with increased power efficiency. A time delay separates the onset of the second boosting operation from the onset of the first boosting operation so as to define a two-step boost.

Abstract: A triple well charge pump comprises a first transistor connected in a diode configuration having a first channel terminal, nominally the source, coupled to a first node, and the second channel terminal, nominally the drain, coupled to its gate and to a second node. A first capacitor has a first terminal coupled to the first node of the charge pump, and a second terminal adapted to receive a first clock signal. A second transistor has a first channel terminal coupled to the second node of the charge pump, and a second channel terminal coupled to its gate and to a third node. A second capacitor has a first terminal coupled to the second node, and a second terminal adapted to receive a second clock signal.

Abstract: An output driver for an integrated circuit performs a precharge function before internal data is available, minimizing the access time for such data. Also, the pull up and pull down circuitry used in the precharge function is separate from the output driver, and independent of the level of the data signal to be driven. A sense circuit senses an initial state of the output pad, before the output signal is supplied to the output pad, which indicates whether a voltage level on the output pad is above a threshold or below the threshold. A precharge circuit includes a pull up circuit and a pull down circuit. The pull up circuit is responsive to the initial state indicating that the voltage level on the output is below the threshold, and the pull down circuit is responsive to the initial state indicating that the voltage level on the output is above the threshold. A detector is coupled to the output, and produces a control signal indicating when output is near the threshold.

Abstract: An on chip voltage generation circuit is provided suitable for use on integrated circuits such as flash memory devices with a low power supply voltage (e.g., 2.7 to 3.6 volts). A voltage boost circuit is coupled to the supply voltage input and to a boost signal, which boosts the on-chip voltage at a node on the integrated circuit in response to a transition of the boost signal. The voltage boost circuit has a first mode which in response to the transition boosts the on-chip voltage at a first rate of boosting until a first threshold, and a second mode which in response to the transition boosts the on-chip voltage at a second rate of boosting until a second threshold. The second rate of boosting in the preferred system is slower than the first rate of boosting. A detection circuit is coupled to the node on the integrated circuit which receives the on-chip voltage, and to the voltage boost circuit.

Abstract: A circuit is provided for applying a negative voltage to the control gate of a floating gate memory cell and a positive voltage to the source drain or channel which comprises a positive voltage source to provide a positive voltage to the source of the cell, and a negative voltage source responsive to the supply voltage to provide a negative voltage to the control gate. A voltage regulator is included that is coupled to the negative voltage source and to the positive voltage source to maintain the negative voltage at a level responsive to the source voltage. The regulator maintains the negative voltage in response to the source voltage so that the electric field remains essentially constant over a range of values of source voltage.

Abstract: A sensing circuit for sensing the logic state of a memory cell which minimizes read times is described which includes a first circuit branch corresponding to an array circuit path and a second circuit branch corresponding to a reference cell circuit path. In operation during the pre-decode interval, additional load and current generation circuitry are enabled in the first circuit path so that the voltage as seen by the sensing input of a sensing circuit comparator is driven to be essentially equivalent to that of the reference signal as established by the reference cell circuit path on the reference input of the sensing circuit comparator. Once the address has been decoded, the additional load circuitry is disabled so as to allow the sensing input of the comparator to transition to a voltage representative of the logic state stored in the memory cell.

Abstract: A non-volatile integrated circuit memory, such as a flash memory device based on floating gate transistor memory cells, with read while write capability is provided using a single address register. The integrated circuit includes at least two independent arrays of memory cells. During a program or an erase operation in one array on the non-volatile integrated circuit, a read operation can be executed in the other array on the same integrated circuit by bypassing the address register altogether, and allowing the register to remain in use by the program or erase operation. A bypass combinatorial logic path for the read process is coupled to the same address inputs as the address register, and operable in parallel with the registered address path.

Abstract: A page mode flash memory or floating gate memory device, including a page buffer based upon low current bit latches, and additional capabilities for parallel read and parallel program verify operations. The present device includes bit latch circuitry and/or method steps that facilitate such parallel operations and avoid data conflicts. Circuitry for separate read signals can serve to isolate the operations. Additionally, circuitry tied to the data verification signal can also be used. A diode type device can be used to isolate signal conditions that might indicate the cell does not need to be programmed. Bit-by-bit precharging of the bit lines can also be employed in order to save precharging power. Additionally, the large capacitance of the dataline might be used to delay discharging a particular dataline, and thereby allow a latch enabling signal to go high, thus eliminating the need for further isolation circuitry, or the like.

Abstract: The present invention provides a new memory device for storage of boot code for microprocessors which boot to either the top or bottom of a memory map on power-up. The device includes a memory array, a first block, and decoders. The first block is defined as rows of the memory array designated for storage of data. The decoders decode a memory access requested for the data. The memory access request may be in either one of a top-down or bottom-up address protocol. In another embodiment, an integrated circuit memory includes: a memory array, a decoder, a control, and a logic gate. The decoders decode a memory access request to select a row of memory array. The control has an output for outputting either a bottom-up or a top-down address protocol signal. The logic gate outputs a logical "Exclusive Or" of the control signal and a corresponding bit of the memory access request, whereby a memory request in a bottom-up address protocol is converted to a memory address in a top-down address protocol.

Abstract: An enhanced word line driver circuit suitable for use on integrated circuits such as flash memory devices with voltage boosting includes a load reduction circuit. In response to a boosted voltage, the load reduction circuit decouples a gate capacitance load of deselected enhanced word line drivers from the boost voltage generator. The reduction of capacitive loading decreases power consumption and shortens the voltage boost time of the memory device.

Abstract: An improved charge pump design is disclosed. This charge pump comprises at least one pumping transistor having a triple well arrangement. This triple pump transistor has a source and a drain region of a first conductive type formed on a first well having an opposite conductive type. A second well having the first conductive type is formed outside of the first well. The source region, first well and second well are set to substantially the same potential. One aspect of this configuration is that the first well forms a semiconductor diode with the drain region. Another aspect of this arrangement is that the body effect of the transistor is reduced. The reduction in body effect reduces the threshold voltage of the transistor. It is found that the above mentioned diode and threshold voltage reduction, singly and in combination, allow the charge pump to operate more efficiently.

Abstract: A method of manufacturing integrated circuits based on providing a test column of memory cells in the devices. Cells in the test column are selected by a portion of the addresses which identifies a row in the main array on the device. A test is executed to determine a characteristic of the device, and the results of that test are mapped to the portion of the address which identifies a row in the array. This produces a characteristic code address for the device which indicates the results of the test. Access to the test column on the device is enabled, and a bit is written in response to the characteristic code address in a memory cell on the test column. During manufacture the test column is read in order to classify the device according to the characteristic.

Abstract: A circuit generates a power on reset signal in response to the changing of a supply potential across a supply node and a reference node from a power down level to a power on level. The circuit comprises a capacitor having a first terminal coupled to the supply node and a second terminal. An output driver, such as an inverter, is coupled between the supply node and the reference node. The output driver has an output coupled to the second terminal of the capacitor. An input driver comprises a circuit which drives the input of the output driver to a level which tracks changes in the supply potential. A clamp transistor, such as a n-channel MOS transistor having a lower threshold than normal transistors in the circuit, is coupled between the input of the output driver and the supply potential. The clamp transistor clamps the input of the output driver to a driver ready level which is below the trip point of the output driver when the supply potential is at a power down level.

Abstract: A charge pump apparatus which comprises first and second active capacitors in series, having a common node between them. The second node of the second active capacitor is coupled to a particular node in the charge pump which drives an output of the charge pump. A pump clock is connect to the first lead of the first active capacitor. A voltage clamp is connected to the particular node and provides a bias point. A dynamic biasing circuit is connected to the common node and charges the common node and the particular node during intervals between transitions of the pump clock to keep both the first and second active capacitors activated during the transitions of the pump clock.

Abstract: A method for determining successful programming of a set of memory cells in an array of floating gate memory cells including bit lines coupled with corresponding columns of cells in the array, word lines coupled with corresponding rows of cells in the array, and bit latches coupled to the respective bit lines. The method includes applying a word line voltage to a word line across which memory cells in the set of memory cells are accessible. A potential applied to memory cells in the set of memory cells is raised. A current load is caused from the bit line. Changes in respective voltage levels of bit lines in the set of bit lines are responded to in parallel to store a constant in bit latches in the set of bit latches coupled to bit lines on which the respective voltage levels pass a determinate threshold during the step of applying a word line voltage. An integrated circuit memory is described.