Abstract: A method and circuit are disclosed for providing sector protection to sectors of nonvolatile memory cells in a nonvolatile memory device. The circuit includes maintaining sector protection information in the core of memory cells in the nonvolatile memory device. In this way, the circuitry and/or algorithms utilized for reading and modifying memory cells in the memory cell core that maintain the sector protection information is the same utilized for reading and modifying the other memory cells in the core.

Abstract: A method is disclosed for a memory cell for a static random access memory. The memory cell includes a pair of cross-coupled CMOS logic inverters that are connected together to form a latch, and a pair of p-channel transmission gate transistors that are connected to the logic inverters for selectively providing access to the latch. The layout of the memory cell includes a rectangular active area in which the p-channel transistors of the memory cell are located. The rectangular active area abuts a similar active area of an adjacent memory cell along a row of memory cells so as to form a single rectangular active area for the p-channel memory cell transistors. The rectangular active area reduces the occurrence of fabrication-related phenomena that adversely effect the performance of the memory cell.

Abstract: An echo cancellation functionality taps a digital transmit signal from a transmit channel for processing through an adaptive filter of an echo channel to generate an echo cancellation signal. The adaptive filter has a transfer function substantially matching an echo transfer function which defines a relationship between the transmit signal and an unwanted echo component corrupting an analog receive signal. The echo cancellation signal is digital-to-analog converted to an analog signal and then subtracted from the analog receive signal to substantially cancel out the unwanted echo component. The echo cancellation functionality may be configured in a training mode to generate an error signal used to adaptively configure the adaptive filter transfer function to substantially match the echo transfer function. When in training mode, certain components of an adaptation loop which contribute to a feedback loop transfer function are selectively by-passed.

Abstract: A method and circuit are disclosed for controlling the write head of a magnetic disk storage device. The circuit includes a pull-up device coupled to a terminal of the write head, for selectively providing a current to the write head though the write head terminal. The circuit further includes parallel-connected current sink circuits, each of which is coupled to the write head terminal and selectively activated to draw current from the write head via the write head terminal. A first transistor is connected in series between the pull-up device and the write head terminal and biased to provide a voltage differential between the write head terminal and the pull-up device. A second transistor is connected in series between the write head terminal and the current sink circuits and biased to provide a voltage differential between the write head terminal and the current sink circuits.

Abstract: A circuit and method are disclosed for asynchronously accessing accessing a ferroelectric memory device. The ferroelectric memory device internally generates timing signals for latching a received address signal and driving the row lines of the device based upon transitions appearing on the received address signal. The circuit receives an address signal and asserts an edge detect signal in response. The address signal is latched following the edge detect a signal being asserted. Address decode circuitry receives the latched address and generates decoded output signals that identify a row of memory cells to be accessed. In this way, a ferroelectric memory device may effectively replace an asynchronous static random access random access memory (SRAM) device.

Abstract: A method and circuit are disclosed for controlling the current level of a differential logic circuit having a current source, input transistors which perform current steering based upon the input to the differential logic circuit, and load transistors. The circuit includes a first transistor that forms a current mirror with the current source, a second transistor coupled to the load transistors so that the operating characteristics of the load transistors substantially match the operating characteristics of the second transistor, and current source circuitry coupled between the first and second transistors. The current level selected in the current source circuitry sets the current level in the differential logic circuit and the resistance of the load transistors so that the output voltage swing of the differential logic circuit stays within an acceptable range of voltages, regardless of the selected current level.

Abstract: A circuit and method are disclosed for determining whether a brushless polyphase motor is spinning in a reverse direction relative to spin direction during normal operation. The circuit receives a back emf signal of a first phase line and determines a polarity of the back emf signal following a back emf signal associated with a second phase line crossing a zero reference level. Based upon the determined polarity of the back emf signal of the first phase line, the circuit selectively asserts an output signal indicating that the motor is spinning in the reverse direction.

Abstract: A circuit and method for performing a stress test on a ferroelectric memory device. The memory device includes a memory cell array having a plurality of row lines, column lines and plate lines. The memory device further includes test circuitry for receiving at least one test control signal and in response to the at least one test control signal allowing a voltage differential to be applied between the column lines and the plate lines, so that a stress voltage may be applied across each of the memory cells at one time.

Abstract: A detection circuit and a test mode circuit incorporating the detection circuit is disclosed. The detection circuit includes an N-channel transistor having a first source, a first gate, and a first drain, wherein the first drain is connected to a supply voltage. The detection circuit also includes a P-channel transistor having a second source, a second gate, and a second drain, wherein the second source is connected to the first source and the second drain provides an output signal indicative of a supervoltage being applied to the first gate. The test mode circuit also includes a memory access cycle time-out feature override circuit.

Abstract: A pair of equivalent controlled impedance buffers are connected in a push-pull configuration to a transformer primary coil. A pair of equivalent pre-drivers are connected to the pair of buffers. Each pre-driver receives a driver input signal and outputs a buffer input signal (based on the input signal) and a DC offset compensation signal. Each buffer receives the buffer input signal from its associated pre-driver for buffered output as a line driver signal to the primary coil. Each buffer further receives the DC offset compensation signal generated its pre-driver to compensate for an offset introduced by the transformer. A balanced bridge hybrid is also connected between the buffer output and internal nodes. An adjustment circuit processes the hybrid output during training mode to generate an adjustment signal for application to an adjustable current source within each buffer.

Abstract: A digital-to-analog converter (DAC) having a first sub-DAC for generating a coarse current level based upon the most significant bits of the digital input signal, and a second sub-DAC for generating a fine current level in response to the least significant bits of the digital input signal. The first sub-DAC is segmented, including a plurality of equally-sized current sources and self-calibration circuitry for calibrating the equally-sized current sources concurrently with generating the coarse current level. The second sub-DAC is itself partially segmented, wherein a first portion of the second sub-DAC includes a plurality of equally-sized current sources and a thermometer decoder associated therewith. The second sub-DAC further includes a plurality of binary-weighted current sources. Current levels generated by the first and second sub-DACs are summed to generate an analog equivalent of the digital input signal.

Abstract: A circuit and method is disclosed for a memory cell for a static random access memory. The memory cell includes a pair of cross-coupled CMOS logic inverters that are connected together to form a latch, and a pair of p-channel transmission gate transistors that are connected to the logic inverters for selectively providing access to the latch. The layout of the memory cell includes a rectangular active area in which the p-channel transistors of the memory cell are located. The rectangular active area abuts a similar active area of an adjacent memory cell along a row of memory cells so as to form a single rectangular active area for the p-channel memory cell transistors. The rectangular active area reduces the occurrence of fabrication-related phenomena that adversely effect the performance of the memory cell.

Abstract: A substantially noise-free data input buffer for an asynchronous device, such as a static random access memory (SRAM). The input buffer generates either a logical true or complement output signal representation of a data input signal and includes timing circuitry to delay an edge transition on the output signal for a predetermined period of time in response to a signal edge transition appearing on the data input signal. The input buffer further includes edge transition detection (ETD) circuitry for generating an initialization signal in response to the generation of the data output signal.

Abstract: A dynamic random access memory (DRAM) device is disclosed. The DRAM device includes a memory cell array having a twisted bit line architecture. The memory cell array includes at least one pair of redundant rows of memory cells. Redundant row decode circuitry is capable of configuring the pair of redundant rows to replace any one row of memory cells having a defect. Each pair of bit lines is coupled to a distinct memory cell from each redundant row of the redundant row pair so that both the true and complement version of a data value is maintained by the redundant row pair. Rows of reference cells are disconnected and/or disabled during a memory access operation involving the redundant row pair. The use of a pair of redundant rows of memory cells to replace a single row of memory cells having a defect substantially reduces the complexity of decode circuitry for enabling the rows of reference cells.

Abstract: A six transistor static random access memory (SRAM) cell with thin-film pull-up transistors and method of making the same includes providing two bulk silicon pull-down transistors of a first conductivity type, two active gated pull-up thin-film transistors (TFTs) of a second conductivity type, two pass gates, a common word line, and two bit line contacts. The bulk silicon pull-down transistors, two active gated pull-up TFTs, and two pass gates are connected at four shared contacts. In addition, the two bulk silicon pull-down transistors and the two active gated pull-up TFTs are formed with two polysilicon layers, a first of the polysilicon layers (poly1) is salicided and includes poly1 gate electrodes for the two bulk silicon pull-down transistors. A second of the polysilicon layers (poly2) includes desired poly2 stringers disposed along side edges of the poly1 gate electrodes, the desired poly2 stringers forming respective channel regions of the pull-up TFTs.

Abstract: An SRAM cell includes a pair of N channel transistors acting as inverting circuits, a pair of N channel transistors which perform the control function for the cell, and a pair of N channel thin film transistors in depletion mode with gate and source shorted to provide load devices for the N channel inverter transistors of the SRAM cell.

Abstract: A method and circuit is disclosed for controlling the write head of a magnetic disk storage device. The circuit includes a pull-up device coupled to a terminal of the write head, for selectively providing a current to the write head through the terminal. The circuit further includes parallel-connected first and second current sink circuits, each of which is coupled to the write head terminal and selectively activated to draw current from the write head via the write head terminal. The circuit further includes a control circuit for individually activating the pull-up device and the first and second current sink circuits. In particular, when reversing the direction of current flow through the write head from a first direction in which current is provided to the write head via the write head terminal to a second direction in which current is drawn from the write head from the write head terminal, both the first and second current sink circuits are activated by the control circuit.

Abstract: A method and circuit are disclosed for maintaining stored data within a ferroelectric memory device. The circuit includes a first circuit for selectively logically inverting the data in the ferroelectric memory device. A second circuit enables the first circuit at the one or more predetermined times. A third circuit logically inverts data to be written to and data read from the ferroelectric memory device following every other predetermined time. In this way, the circuit is capable of inverting the data values stored in the ferroelectric memory device, thereby reducing the susceptibility of imprint.

Abstract: A redundant circuit and method for a semiconductor memory device is disclosed. The redundant circuit includes a programmable circuit for selectively generating at least one first address corresponding to a defective memory row or column line, and shifter circuitry for remapping second addresses which are greater than the first address to row/column lines. For each second address which is greater than the first address, the shifter circuitry remaps the second address to a row/column line which was initially mapped to an immediately higher address relative to the second address. The programmable circuit is capable of generating a plurality of first addresses corresponding to a plurality of defective memory row or column lines.

Abstract: A circuit and method are disclosed for controlling bootstrap circuitry that boosts a voltage level appearing on word lines of a dynamic random access memory device. During execution of a memory access operation, the circuit is adapted to enable the bootstrap circuitry a period of time following the memory device's sense amplifiers initially powering up. The circuit senses when the voltage appearing on a select bit line crosses a predetermined voltage level, and enables the bootstrap circuitry thereafter. In this way, a period of time elapses between the sense amplifiers turning on and the activation of the bootstrap circuitry, thereby reducing noise introduced from the sense amplifiers turning on from impacting the operation of the bootstrap circuitry.