Abstract: An output driver circuit an integrated circuit memory device prevents crowbar currents from occurring. The output driver uses just one resistive element having multiple taps so that the amount of silicon area used for slew rate control is minimized. The signals which control the output driver devices are carefully balanced for no skew and cross at a voltage level of Vcc/2 so that there is no crowbar current generated during tri-stating of the output driver output signal.

Abstract: According to the present invention, the data access time of a chip select condition of a synchronized memory integrated circuit device is pipelined so that it approximates the normal access time of data for the device. The response time to the chip enable signal during a deselect condition is immediate and thus is not pipelined. The access time of data due to a chip select condition is pipelined and matched with the normal access time of data propagation so that any access time pushout previously incurred when transitioning the device output signal from a high impedance (disabled) to a low impedance (enabled) state is eliminated. The circuitry of the present invention tri-states the output pin of the synchronized memory device on the initial rising edge of an external clock signal supplied to the device upon a deselect condition. Upon the first cycle of the select condition, when the external clock signal initially rises, an Output Disable Internal signal remains a high logic state.

Abstract: An electrical power protection integrated circuit provides protection against reverse battery and overvoltage conditions that is particularly of value in automotive applications in which reverse battery and overvoltage conditions are commonplace. The electrical power protection integrated circuit device contains a reverse battery condition protection element, supplied either directly or indirectly from a battery power source, that protects against a reverse battery condition of the battery power source and an overvoltage protection element coupled to the reverse battery condition protection device that protects against an overvoltage condition of the battery power source and produces a protected power output that is isolated from both battery overvoltage and reverse battery voltage conditions. Additionally, the integrated circuit device can further produce an auxiliary protected power output that is isolated from reverse battery voltage conditions.

Abstract: A circuit that compensates for delays induced by clock generation logic and distributed clock drivers in phase lock loop applications is disclosed. The circuit is a phase lock loop (PLL) which contains a clock synchronization circuit that operates to synchronize a transition edge of a signal generated by a frequency divider against a distributed clock signal generated by a clock output driver of the circuit. The synchronization occurs unless the clock synchronization circuit is disabled.

Abstract: The entire data path of a synchronous integrated circuit device is initialized in a test mode upon power-up of the synchronous integrated circuit device. Upon power-up of the integrated circuit device in the test mode, a clock signal (either an external clock signal or an associated internal clock signal) is internally clocked. As the clock signal goes to a low logic state upon power-up of the device, a master latch (flip-flop) element of the integrated circuit device is loaded with data and is allowed to conduct; a slave latch (flip-flop) element of the integrated circuit device does not conduct. As the clock signal goes to a high logic state, the data in the master latch is latched. Also upon the high logic state of the clock, the slave latch element is loaded with data and is allowed to conduct.

Abstract: A method and control circuit structure for externally controlling the width of a write pulse of a synchronous integrated circuit memory device is disclosed. The method and control circuit provide for a test mode in which the width of the write pulse of the synchronous integrated circuit memory device may be externally controlled to be entered. After entering the test mode, the start of a write pulse of the synchronous integrated circuit memory device is triggered by a transition of a clock signal from a first logic state to a second logic state. The termination of the write pulse is accomplished by selective manipulation of an external control signal external to the synchronous integrated circuit memory device.

Abstract: A non-linear integrator of a closed loop integration system selectively modifies the gain of the closed loop integration system in order to avoid system saturation while still experiencing high gain in a desired linear portion of the system. A non-linear integrator structure and method allow the gain of the closed loop integration system to be selectively modified in order to avoid saturation while experiencing high gain. The non-linear integrator includes an amplifier, a current source element which generates a bias input signal, a bias circuit which provides the bias input signal to the amplifier and allows the bias input signal to be selectively modified, a storage element coupled to the amplifier, and a gain element, coupled to the storage element, which produces an output signal determined by voltage on the storage element. A voltage input signal and a bias input signal are supplied to the amplifier which generates an amplifier output signal.

Abstract: The present invention ensures that the entire data path of the synchronous integrated circuit device composed of master and slave latches is initialized upon power-up in a test mode, thereby overcoming a prior art problem of non-initialization of the device data path. In the test mode, the master clock signal is initialized internally to the synchronous integrated circuit device to allow the master latch to conduct. A clock signal which is a derivative of a master clock signal is controlled to be equal to a first logic state in order to control a slave latch element of the synchronous integrated circuit device to conduct, regardless of the state of the master clock signal. Controlling the clock signal to be equal to the first logic state allows the clock signal to be able to control the slave latch element so that entire data path of the integrated circuit device is initialized upon power-up of the device in the test mode.

Abstract: According to the present invention, when faulty data bits in a cache memory are not repairable through conventional repair means such as row/column redundancy, the faulty bits are made inaccessible to the microprocessor by rendering invalid an appropriate line of data in the cache memory containing the faulty data. The present invention employs address detection circuitry which detects when a faulty data address stored in the tag RAM is presented during a microprocessor memory cycle and forces the valid bit for that faulty data to a predetermined logic level. When the valid bit associated with the faulty data is set to the predetermined logic level, the tag RAM generates a signal indicative of a "miss" condition. The "miss condition" is communicated to the microprocessor which must access the requested data from main memory, thus effectively bypassing the faulty data. The address detection circuitry of the invalidation circuitry may be expanded to handle any number of faulty data.

Abstract: According to the present invention, the data access time of a chip select condition of a synchronized memory integrated circuit device is pipelined so that it approximates the normal access time of data for the device. The response time to the chip enable signal during a deselect condition is immediate and thus is not pipelined. The access time of data due to a chip select condition is pipelined and matched with the normal access time of data propagation so that any access time pushout previously incurred when transitioning the device output signal from a high impedance (disabled) to a low impedance (enabled) state is eliminated. The circuitry of the present invention tri-states the output pin of the synchronized memory device on the initial rising edge of an external clock signal supplied to the device upon a deselect condition. Upon the first cycle of the select condition, when the external clock signal initially rises, an Output Disable Internal signal remains a high logic state.

Abstract: According to the present invention, faulty lines of data of a set associative cache memory containing one or more faulty data bits which are not repairable through conventional repair means such as row/column redundancy, are not updated following a cache miss condition and thereby effectively bypassed. Replacement logic circuitry detects and controls the state of a replacement status bit associated with each line of data of the set associative cache memory to determine if the line of data in the cache should be updated or bypassed. Thus, when replacing a line of data, the replacement logic circuitry detects the address of a faulty line of data in a particular set and avoids updating that faulty line of data in favor of updating another line of data of another set.

Abstract: A comparator with hysteresis which has a bias current circuit, a differential input stage, and an output stage is disclosed. The differential input stage uses a parallel transistor and an enabling transistor connected in parallel to one of the differential pair transistors to create hysteresis. The parallel transistor and enabling transistor are used to generated an effective offset voltage which must be overcome for the comparator to switch states.

Abstract: A bias circuit for generating a bias voltage over variations in the power supply voltage and over process parameters is disclosed. The bias circuit utilizes a voltage divider to generate a divided voltage based on the power supply value. The divided voltage is applied to the gate of a modulating transistor (biased in saturation) in a current mirror, which controls a current applied to a linear load device biased in the linear region. The voltage across the load device determines the bias voltage. Variations in the power supply voltage are thus reflected in the bias voltage, such that the gate-to-source voltage of the series transistor is constant over variations in power supply voltage. Variations in process parameters that produce different transistor current drive characteristics are reflected in a variations of the bias voltage produced by the linear load device.

Abstract: According to the present invention, a structure for holding broken select lines in a memory array deselected addresses the prior art problems associated with floating broken select lines, such as standby current and disruption of attached memory cells. The structure is a non-linear, high impedance device which is placed on the end of select lines so that if a select line is broken during fabrication, the non-linear, high impedance device will hold the broken end of the select line to the desired deselect voltage. Select lines which have a driver at one end only and are broken during fabrication, but have the non-linear, high impedance device on the other end, are not allowed to float. The non-linear, high impedance device is also suitable for select lines which are not broken and previously were anchored at just one end.

Abstract: A method for stress testing a memory array in an integrated circuit. Control circuitry selects a plurality of row lines at one time. An overvoltage suitable for stressing the cells of the array is placed on the bit lines. Because a block of cells has been selected, the overvoltage is applied to all cells of the block. The block of cells selected may be either the entire memory array or a portion of the memory array. The selected rows remain selected for the duration of the stress test. Because the overvoltage is applied directly to selected cells, the full overvoltage will be used to stress the transistor gates for the entire test period. In this manner, latent defects within the memory array can be detected.

Abstract: The cross-sectional area of a thin-film transistor (TFT) is decreased in order to minimize bitline to supply leakage of the TFT. This is accomplished by utilizing a spacer etch process to manufacture a TFT having a very narrow and thin channel in a controllable manner. The spacer dimensions of the TFT may be adjusted by simply modifying the thicknesses of the poly gate and the channel poly. The channel thickness is limited by the thickness of the deposited channel polysilicon which may be as thin as approximately 300 .ANG. to 500 .ANG., and the channel width of the TFT corresponds to the height of the spacer etched along the polysilicon gate of the device which may be as small as approximately 0.15 to 0.25 .mu.m.

Abstract: A voltage regulator with load pole stabilization is disclosed. The voltage regulator consists of an output stage, a comparator stage, and an active load. The active load draws current from the output of the voltage regulator inversely proportional to the current demand on the voltage regulator. When the output current demand is low, the active load draws relatively low current. When the output current demand is large, the active load draws a relatively large amount of current. Consequently, the disclosed voltage regulator has high stability without consuming excess power.

Abstract: According to the present invention, a structure and method provides for single bit failures of an integrated circuit memory device to be analyzed. According to the method for analyzing a single bit failure of an integrated circuit memory device, a test mode is entered, bitline load devices of the integrated circuit memory device are turned off, a single bit of the integrated circuit memory device is selected, the device is placed into a write mode, a plurality of bitlines true and a plurality of bitlines complement of the integrated circuit memory device not associated with the single bit are then set to a low logic level, the bitline true and the bitline complement associated with the single bit is connected to a supply bus and a supply complement bus which is connected to test pads. Finally, the electrical characteristics of the single bit can be monitored on the test pads.

Abstract: According to the present invention, a modification of standard successive approximation analog to digital converter circuitry may be utilized to measure an unknown analog value and to produce a digital value after conversion that automatically contains an offset value with respect to a given measurement range. The offset achieved by the successive approximation A/D converter is proportional to an external reference which is used as the reference for the successive approximation A/D converter. The digital value produced according to the present invention is not representative of a raw measurement value but rather is representative of a value with respect to a given measurement range; thus, a digital value of 0 may indicate the minimum value of a given measurement range rather than a value of 0 Ohms, 0 volts, or 0 Amps. This may be expressed in equation form where the desired conversion value is represented by:k(X.sub.unknown -X.sub.offset)where k is a constant, X.sub.

Abstract: A circuit for driving a voice coil motor used to position the heads of a disk drive is disclosed. The circuit consists of a an H-bridge circuit, a controller, and a feedback loop. The feedback loop prevents the BEMF from driving a voltage on the voice coil motor above the supply voltage.