Abstract: A high speed address sequencer allows for a generation of address signals using a clock with higher frequency. The high speed address sequencer can be used in many semiconductor devices, especially in flash memory devices. By reducing a number of gate delays, the high speed address sequencer can generate all address signals in a reduced time period. By using an address signal as a clock for generation of some of the other address signals, the high speed address sequencer is allowed more time to generate all address signals with a given clock frequency. The reduction in the number of gate delays can be combined with the use of the address signal as a clock.

Abstract: An address buffering and decoding architecture for a multiple bank (or N bank) simultaneous operation flash memory is described. For the duration of a read operation at one bank of the N banks, a write operation can only be performed on any one of the other N-1 banks. For the duration of a write operation at one bank of the N banks, a read operation can only be performed on any one of the other N-1 banks. The address buffering and decoding architecture includes a control logic circuit, an address selection circuit located at each of the N banks, and address buffer circuitry. The control logic circuit is used to generate N read select signals to select one bank of the N banks for a read operation and N write select signals to select another bank of the N banks for a write operation. Each address selection circuit is configured to receive from the control logic circuit a respective one of the N read select signals and a respective one of the N write select signals.

Abstract: A burst read mode operation is provided that boosts the voltage of a word line while the bit lines of the row are selected for reading. When the column group address bits read the last column group of cells in the row, a pulse signal is generated which temporarily reduces the boosted voltage to allow the X-decoder to select the next word line. An alternative delay element is also provided which generates an ATD pulse with a longer duration when the column group address bits are at the end of a row and a shorter duration pulse at other times.

Abstract: A memory device (100) includes a core cell array (102), a sense amplifier circuit (110), data lines (120), each having a length. The memory device further includes bit lines (118) extending from the core cell array and a selection circuit (106) configured to selectively couple a bit line to a data line in response to an input address. Bias circuits (130) are distributed along the length of the data lines and are configured to apply an initial voltage to the data line, reducing the read access time of the memory device. The bias circuits 130 may be positioned to accommodate varying lengths of the data lines and varying capacitance of the data lines.

Abstract: An address transition signal generator for a dual bank flash memory device is disclosed. The generator includes signal transition detectors which monitor control signals of the device for transitions in their logical values. Upon detection of a signal transition, the transition detectors send a signal across equidistant signal paths to bank address transition detect signal generator circuits. This results in simultaneous generation of the address transition detect signal from each of the bank address transition detect signal generator circuits.

Abstract: A clock generator circuit in response to an external output enable signal generates an internal clock signal that is delayed to increase the reliability of the data outputted from the flash memory. A clock trigger generator circuit by decoding address signals generates an internal clock signal to reduce the latency time of the output of data with respect to the external clock signal. A bypass signal is provided to disable the clock trigger generator circuit. An output circuit provides a bypass data path to additionally reduce the latency time of the outputting of data for a burst mode flash memory. A decoder counter selector circuit provides a “look-ahead” address decoding scheme to reduce the time needed to output data.

Abstract: A content addressable memory (CAM) circuit (200) is used as a data storage circuit to store information about operational mode and timing in a flash memory chip (100). To minimize current drain in a standby mode, the CAM circuit is placed in a low power state. To prevent unwanted switching of the output node (240) and eliminate excess current drain and mode switching of other circuits in the flash memory chip, the output of the CAM circuit is latched.

Abstract: A flash memory system capable of simultaneous operation comprises upper and lower memory banks of flash memory cells, reference cells generating reference signals, a switch coupled to the reference cells and upper and lower sense amplifiers coupled to the switch and to the upper and lower memory bank, respectively. The switch steers the appropriate reference signal to the appropriate upper sense amplifier along one upper signal line and steers the appropriate reference signal to the appropriate lower sense amplifier along a lower signal line. The upper and lower sense amplifiers generate comparison signals in response to reference signals and data stored in the upper and lower memory bank, respectively.

Abstract: A flash Electrically-Erasable Programmable Read-Only Memory (EEPROM) includes a plurality of floating gate transistor memory cells, a plurality of wordlines connected to the cells and a power source for generating a low power supply voltage on the order of 3 V or less. A wordline driver includes a booster for boosting the supply voltage to produce a wordline read voltage which is higher than the supply voltage, and applying the wordline voltage to a wordline. An upper clamp limits a maximum value of the wordline voltage to prevent read disturb. The upper clamp can be configured to reduce an amount by which the maximum value varies with the supply voltage, or to limit the maximum value to substantially a predetermined value.

Abstract: A system for optimizing the equalization pulse of a read sense amplifier is disclosed. A number of capacitor circuits are provided that can be coupled to a timing circuit in a variety of combinations. The different combinations of coupled and decoupled capacitor circuits result in different durational lengths of the equalization pulse. A testing sequence determines the optimal durational length of the equalization pulse by testing the different combinations of coupled capacitors. The optimal combination is then permanently stored in attribute cells for optimizing the equalization pulse in normal operation.

Abstract: A flash memory chip including a synchronization circuit for multiplexed sense amplifier output signal paths is disclosed. The synchronization circuit includes a signal generator, sense amplifiers and an output multiplexer. The arrival of data from the sense amplifiers to the output multiplexer is equalized. Equalization is achieved by adjusting the signal path length, and thereby the resistance and capacitance, of the signal paths from the signal generator to the sense amplifiers which carry the signal to cause the sense amplifiers to transmit their data to the output multiplexers.

Abstract: An address transition signal generator for a dual bank flash memory device is disclosed. The generator includes signal transition detectors which monitor control signals of the device for transitions in their logical values. Upon detection of a signal transition, the transition detectors send a signal across equidistant signal paths to bank address transition detect signal generator circuits. This results in simultaneous generation of the address transition detect signal from each of the bank address transition detect signal generator circuits.

Abstract: A clock control circuit receives an external clock signal and generates an internal clock signal. Through use of internal programming and an external trigger signal, the clock control circuit blocks out one or more of the clock cycles of the external clock signal to generate the internal clock signal. The clock control circuit can be used in any semiconductor device, and especially in synchronous flash memory devices with a burst operation. In the synchronous flash memory devices, one or more of the internal clock cycles are blocked out to account for increased delays during certain data sensing operations such as word line switching during data reading. In the synchronous flash memory devices, the sensed data is stored in input/output buffers and transferred out synchronously to the external clock signal.

Abstract: A flash-erasable semiconductor memory device comprises a memory cell array including a plurality of memory cell transistors each having an insulated floating gate for storing information and a control electrode provided on said floating gate, wherein the flash-erasable semiconductor memory device includes a write control circuit supplied with a write control signal, when writing information. The write control circuit produces a control signal such that a leading edge of the drain control signal appears after a leading edge of the gate control signal. Further, the gate control circuit shuts off the gate control signal such that a trailing edge of the gate control signal appears after a trailing edge of the drain control signal.

Abstract: A flash-erasable semiconductor memory device comprises a memory cell array including a plurality of memory cell transistors each having an insulated floating gate for storing information and a control electrode provided on said floating gate, wherein the flash-erasable semiconductor memory device includes a write control circuit supplied with a write control signal, when writing information. The write control circuit produces a control signal such that a leading edge of the drain control signal appears after a leading edge of the gate control signal. Further, the gate control circuit shuts off the gate control signal such that a trailing edge of the gate control signal appears after a trailing edge of the drain control signal.

Abstract: A flash-erasable semiconductor memory device has a memory cell array including a plurality of memory cell transistors each having an insulated floating gate for storing information and a control electrode provided on the floating gate, wherein the flash-erasable semiconductor memory device includes a write control circuit supplied with a write control signal, when writing information. The write control circuit produces a control signal such that a leading edge of the drain control signal appears after a leading edge of the gate control signal. Further, the gate control circuit shuts off the gate control signal such that a trailing edge of the gate control signal appears after a trailing edge of the drain control signal.

Abstract: A flash memory device is divided into two or more banks. Each bank includes a number of sectors. Each sector includes flash memory cells. Each bank has a decoder that selectively receives an address from an input address buffer or from an internal address sequencer controlled by an internal state machine. The output data for each bank can be communicated to a read sense amplifier or a verify sense amplifier. The read sense amplifier connects to the output buffer while the verify sense amplifier connects to the state machine. When one bank receives a write command, the internal state machine takes control and starts the program or erase operation. While one bank is busy with a program or erase operation, the other bank can be accessed for a read operation. Power is supplied for each of the read and write operations via an internal multiplexed multi power supply source that provides an amount of power needed based on the memory operation being performed.

Abstract: A flash-erasable semiconductor memory device comprises a memory cell array including a plurality of memory cell transistors each having an insulated floating gate for storing information and a control electrode provided on said floating gate, wherein the flash-erasable semiconductor memory device includes a write control circuit supplied with a write control signal, when writing information. The write control circuit produces a control signal such that a leading edge of the drain control signal appears after a leading edge of the gate control signal. Further, the gate control circuit shuts off the gate control signal such that a trailing edge of the gate control signal appears after a trailing edge of the drain control signal.

Abstract: A flash-erasable semiconductor memory device has a memory cell array including a plurality of memory cell transistors each having an insulated floating gate for storing information and a control electrode provided on the floating gate, wherein the flash-erasable semiconductor memory device includes a write control circuit supplied with a write control signal, when writing information. The write control circuit produces a control signal such that a leading edge of the drain control signal appears after a leading edge of the gate control signal. Further, the gate control circuit shuts off the gate control signal such that a trailing edge of the gate control signal appears after a trailing edge of the drain control signal.

Abstract: A semiconductor memory device has 2.sup.n word lines, a plurality of bit lines, a plurality of nonvolatile memory cells disposed at each intersection of the word lines and the bit lines, a write circuit for writing data to a memory cell located at an intersection of selected ones of the word lines and the bit lines, and a sense amplifier for reading data out of the memory cells. Further, the semiconductor memory device comprises a first unit for simultaneously selecting a block of 2.sup.m (n>m) word lines among the 2.sup.n word lines, and a second unit for not selecting a block of 2.sup.k (m>k) word lines among the 2.sup.m word lines. The second unit does not select the block of 2.sup.k word lines, and selects a block of 2.sup.k word lines prepared outside the 2.sup.n word lines when any one of the 2.sup.k word lines among the 2.sup.m word lines is defective.