Abstract: A clock waveform synthesizer that will create a timing signal that is a multiple of the frequency of an master clock is disclosed and has the capability to programmably adjust the rising edges and falling edges of the synthesized waveform within the period of the master clocks. The clock waveform synthesizer has a multi-tapped delay line. The multi-tapped delay line will create replications of the master clock that are incrementally delayed from the master clock to create a plurality of delay signals. A fraction of the plurality of delay signals will be the inputs to each of a plurality of multiplexers. A select port on each of the multiplexers will receive a select signal to choose one delay signal of the fraction of the plurality of delay signals. The one selected delay signals will be the input to the set terminals and reset terminals of a plurality of edge-triggered set/reset flip-flops.

Abstract: A pitch synchronous sinusoidal synthesizer for multi-band excitation vocoders will produce excitation signals necessary to artificially mimic speech from input data. The input data will contain the pitch frequencies for current and previous synthesizing frame samples, starting phase information for all harmonics within the current synthesizing frame sample, magnitudes for each of the harmonics present within the current synthesizing frame sample, the voiced/unvoiced decisions for each of the harmonics within the current frame sample, and an energy description for the harmonics of the current synthesizing frame sample. The pitch synchronous sinusoidal synthesizer will produce the synthetic speech with a minimum of the distortion caused by the sampling and regeneration of the speech excitation signals. The pitch synchronized sinusoidal synthesizer has a plurality of pitch interpolators.

Abstract: An input buffer within an integrated circuit capable of receiving an input signal that complies with the electrical characteristic voltage levels of TTL, LVTTL, SSTL, or GTL, buffering the input signal, and converting the input signal to an output signal having voltage levels acceptable to internal circuitry of the integrated circuits is described. The input buffer will have an adjustable threshold trip point at which the input signal will cause the output signal to change between a first logic state and a second logic state. The adjustable threshold trip point will be determined by an adjustment voltage circuit that is immune to variation in semiconductor processing parameters, power supply voltage and operating temperature.

Abstract: A DRAM cell capable of storing two bits of digital data as four levels of stored charge within the DRAM cell is disclosed. The four level DRAM cell has a pass transistor, a trench capacitor, and a stack capacitor. The pass transistors has a source connected to a bit line voltage generator to control placement of the charge within the four level DRAM cell, a gate connected to a word line voltage generator to control activation of the DRAM cells, and a drain. The trench capacitor has a top plate connected to the drain and a bottom plate connected to a substrate biasing voltage source. The stack capacitor has a first plate connected to the drain and a second plate connected to a coupling-gate voltage generator. The coupling-gate voltage generator will provide four levels of voltage that will indicate the level of charge to be stored within the four level DRAM cell. An interconnecting block that will interconnect the top plate of the trench capacitor to the first plate of the stack capacitor.

Abstract: A pre-charge and isolation circuit for a folded bit line DRAM array to reduce noise coupling between adjacent bit lines of a DRAM array by allowing only one bit line to be connected to a sense amplifier, while the complementary bit line remains at a reference voltage level is disclosed. The isolation pre-charge circuit will be connected to a pair of bit lines within a DRAM array to pre-charge portions the pair of bit lines to a reference voltage level and to connect a selected DRAM cell to a latching sense amplifier.

Abstract: A DRAM device having improved performance of peripheral circuitry is described. The performance is improved by selectively having MOS transistors with a thinner gate oxide in peripheral circuits having a lower voltage applied to their gate electrodes. The DRAM device will maintain reliability by having MOS transistors with a thicker gate oxide in the memory cells and selected peripheral circuitry that are subjected to a higher voltage at their gate electrodes. Further this invention describes methods of fabricating the DRAM device with selectively placed multiple gate oxide thickness.

Abstract: A method to program data to and erase data from a split gate flash EEPROM to improve programming and erasing speed, and to improve endurance is disclosed. The programming the split gate flash EEPROM cell is accomplished by simultaneously applying a first positive voltage to the control gate, applying a first moderately negative voltage to the semiconductor substrate, applying a slight potential to the drain region to supply a constant programming current, and applying a second positive voltage to the drain region. The first positive voltage, the first moderately negative voltage, the slight positive potential and the second positive voltage are applied for a sufficient time to cause electrons to be trapped on the floating gate.

Abstract: A DRAM cell structure having charge amplification is disclosed. The DRAM cell has a capacitor to store an electrical charge. The DRAM cell further has a MOS transistor. The gate of the MOS transistor is coupled to a word line control to activate and deactivate the MOS transistor. The drain MOS transistor is coupled to one plate of the capacitor. The DRAM cell has a bipolar transistor to amplify the electrical charge stored on the capacitor. The bipolar transistor has a base that is the source for the MOS transistor. The base of the bipolar transistors is formed by masking and implanting a material of the first conductivity type adjacent to the gate to form the base. The collector of the bipolar transistor is the semiconductor substrate. The bipolar transistor has an emitter coupled to a bit-lines control which when activated will sense the charge amplified by the bipolar transistor.

Abstract: A dynamic threshold voltage MOSFET to provide increase drain-to-source saturation current (I.sub.DSsat) and lower off current (I.sub.off) is described. The dynamic threshold voltage MOSFET has a first diffusion-well of a material of a first conductivity type formed at the surface of the substrate to form a bulk region. A source region and a drain region of a material of a second conductivity type are diffused into the diffusion-well. A first gate is then placed on a first oxide surface above the substrate between the source and drain regions. An accumulated base bipolar transistor is then placed on the semiconductor substrate. The base of the accumulated base bipolar transistor is connected to the gate, the emitter is connected to the diffusion-well. A resistor is connected between the emitter of the accumulated base bipolar transistor and a substrate biasing voltage source.

Abstract: A stacked gate memory cell having a retention time approaching that of an EEPROM cell and a program and erase time approaching that of a DRAM cell is disclosed. A stacked gate memory cell is fabricated upon a semiconductor substrate by implanting a deep diffusion well in the semiconductor substrate. Next a second diffusion well is implanted in the deep diffusion well. A MOS transistor is formed by implanting a drain diffusion and a source diffusion in the second diffusion well at a channel length apart. The source will be strapped to the second diffusion well. A tunnel oxide is placed on a top surface of the semiconductor substrate in a channel area between the source and drain. A polysilicon gate electrode is placed on the tunnel oxide above the channel area. An insulating layer is then placed on the surface of the semiconductor substrate. A stacked capacitor is formed above the MOS transistor on the surface of the insulating layer.

Abstract: A method to erase data from a flash EEPROM cell while electrical charges trapped in the tunnel oxide of a flash EEPROM cell are eliminated to maintain proper separation of the programmed threshold voltage and the erased threshold voltage after extended programming and erasing cycles. The method to erase a flash EEPROM cell begins by first applying a first relatively high positive voltage pulse to the source of the flash EEPROM cell. Simultaneously a ground reference voltage is applied to the control gate and to the semiconductor substrate. At this same time the drain is floating. The flash EEPROM cell is then detrapped by floating the source and drain and applying a second relatively high positive voltage pulse to the semiconductor substrate. At the same time a relatively large negative voltage pulse is applied to the control gate.

Abstract: A method and means to estimate the pitch of a speech or acoustic signal within a vocoder begins with the center clipping and low-pass filtering of the speech or acoustic signal to eliminate the formants from the speech or acoustic signal. An error function for each pitch is calculated for each pitch within the speech or acoustic signal. A fast tracking method is used to select the estimated pitch for the pitch or acoustic signal. A final check for the doubling of the pitch will minimize any incorrect estimation of the pitch.

Abstract: A voltage limiting isolation circuit for pairs of bit lines within a row of DRAM cells to reduce noise coupling will selectively connect and disconnect the portions of a primary and a complementary bit lines, onto which DRAM cells are attached, from the portions of the primary and the complementary bit lines, onto which latching sense amplifier and pre-charge and equalization circuit are attached. The voltage limiting bit line isolation circuit has two sets of serially connected N-type MOS transistors and first P-type MOS transistors placed on the primary bit line and the complementary bit line. Isolation voltage control circuits will provide voltages to the gates of the N-type MOS transistors and P-type MOS transistors to activate and deactivate the voltage limiting isolation control circuit.

Abstract: A multiple phase latched type synchronized clock circuit that will create a multiple phases of an internal clock signal in an integrated circuit that is synchronized with an external system clock signal is disclosed. A latched type clock synchronizer circuit has an input buffer circuit to receive the external input clock to create a first timing clock. The input buffer is connected to a delay monitor circuit to delay the first timing clock by a first delay factor to create a second timing clock. A delay measurement latch array is connected to the input buffer circuit and the delay monitor circuit to create a latched measurement signal, which indicates a period of time between a second pulse of the first timing clock and a first pulse of the second timing clock. A multiple delay array is connected to the input buffer to receive the first timing clock and will create multiple pluralities of incrementally delayed timing clocks.

Abstract: An accumulated-base bipolar junction transistor and an application of said transistor is described. A base region of an accumulated-base bipolar junction is formed by the implantation and then the diffusion of a first dopant material into the semiconductor substrate. A base contact region is a rectangular ring of a second dopant type that is implanted and annealed into the base region. The base contact region is to form a low resistance path from the base region to external circuitry. A collector region is formed by the implantation and annealing of third dopant into the base region in the form of a rectangular ring within the base contact region and a first distance from the base contact region. An emitter region is a rectangular form implanted and annealed of the third dopant within the collector region and a second distance from the collector region.

Abstract: A multilevel DRAM sensing structure to detect the level of charge and interpret the digital data from a DRAM cell is disclosed. The multi-level sense amplifier structure has a first and second bit line each having a first and second section. A pair of isolation switch transistors separate the first section of the first bit line from the second section of the first bit line. The first section of the second bit line is separated from the second section of the second bit line by a second pair of isolation switch transistors. A latching sense amplifier has a first input connected to one of the pairs of isolation switch transistors, a second input connected to the other pair of isolation switch transistors, and an output connected to external circuitry. The output will have the digital data represented by the charge in the DRAM cell.

Abstract: A DRAM cell capable of storing two bits of digital data as four levels of stored charge within the DRAM cell is disclosed. The four level DRAM cell has a pass transistor, a trench capacitor, and a stack capacitor. The pass transistors has a source connected to a bit line voltage generator to control placement of the charge within the four level DRAM cell, a gate connected to a word line voltage generator to control activation of the DRAM cells, and a drain. The trench capacitor has a top plate connected to the drain and a bottom plate connected to a substrate biasing voltage source. The stack capacitor has a first plate connected to the drain and a second plate connected to a coupling-gate voltage generator. The coupling-gate voltage generator will provide four levels of voltage that will indicate the level of charge to be stored within the four level DRAM cell. An interconnecting block that will interconnect the top plate of the trench capacitor to the first plate of the stack capacitor.

Abstract: A method to erase data from a flash EEPROM while electrical charges trapped in the tunneling oxide of a flash EEPROM are eliminated to maintain proper separation of the programmed threshold voltage and the erased threshold voltage after extended programming and erasing cycles. The method to erase a flash EEPROM cell begins by first applying a moderately high positive voltage pulse to the source of the EEPROM cell. Simultaneously, a first relatively large negative voltage is applied to the control gate. While a ground reference potential is applied to the semiconductor substrate. At this same time the drain is floating. The flash EEPROM cell is then detrapped by floating the source and drain and applying the ground reference potential to the semiconductor substrate. At the same time a second relatively large negative voltage pulse is applied to the control gate.

Abstract: A reciprocating or ping-pong voltage boosting circuit is described. The ping-pong boosting circuit has a first and a second boost circuit connected between the power supply voltage source and a ground reference point to generate a first instance and a second instance of a boost voltage. The reciprocating circuit has a switching circuit to alternately place the first and second instance of the boost voltage upon the signal line to bring the voltage level of the signal line to that of the boost voltage. A boost control circuit will provide a switching signal that will control the alternate placing of the first and second instances of the boost voltage upon the signal line. The boost control circuit will provide a boost signal that will cause the first and second boost circuits to generate the first and second instances of the boost voltage.