Abstract: The present invention relates to a system for neutralizing charge injection problems in a switched current system. The system is comprised of a PMOS transistor coupled in parallel with an NMOS switch transistor. If the channel area of the PMOS transistor and the NMOS transistor are equal, then the clock signal to the PMOS transistor must be adjusted to neutralize the negative channel charges of the NMOS transistor. However, if the clock signal to both the PMOS transistor and the NMOS transistor are equal, then the dimension of the PMOS transistor must be smaller than the NMOS transistor in order to neutralize the negative channel charges of the NMOS transistor.

Abstract: A method and system for testing a digital counter of mn bits comprises dividing the counter into m segments, each of n bits. For test purposes, the counter then is further divided into first and second m segment groups. Multiplex gates are used between the segments and are controlled by sensing the condition of the most significant bits of the most significant one of the m segments for applying clock pulses to verify specific connections between various bits of the counter for the first four cycles of clock pulses applied during the test mode. After these four cycles, gating circuits coupled with the most significant bits of the most significant one of the m segments are used to automatically switch the remainder of the test connections to the second group to verify all of the remaining connections in the counter, with full testing of the counter being accomplished in 2.sup.n +2 cycles of clock pulses.

Abstract: A microprocessor provides for a single-cycle and a dual-cycle instruction mode. In the single-cycle mode, certain instructions, e.g., a "shift plus add" instruction, are performed in a single cycle with a relatively low clock rate. In the dual-cycle mode, the shift is performed in the first cycle and the add is performed in the second cycle with a relatively high clock rate. In the dual-cycle mode, a cycle can be dropped if the shift amount is zero or one of the operands is zero. A system designer and/or a programmer can select the mode to maximize throughput.

Abstract: A quad flat pack arrangement which provides for an electrically enhanced integrated-circuit package structure is disclosed. An integrated-circuit die is centrally attached to the top surface of a thermally-conductive, and electrically conductive or insulated substrate. A lead frame having a plurality of inwardly-extending bonding fingers has the bottom sides thereof attached to the top surface of the substrate by a non-conductive adhesive so that an open portion thereof overlies the integrated-circuit die. The plurality of bonding fingers are disposed so as to peripherally surround the integrated-circuit die. A double-sided printed circuit board having first and second conductive layers disposed on its opposite sides is disposed over and bonded to the lead frame. Bonding wires are used to interconnect bonding pads on the integrated-circuit die to the first and second conductive layers. A plastic material is molded around the substrate, die, lead frame, printed circuit board and conductive layers.

Abstract: A method and a computing device for the multiplication/multiplication-accumulation of signed numbers, respectively of N bits and N-1 bits, generated a subword of N bits selectable from the result of 2N-1 bits using a multiplier/multiplier-accumulator incorporating a register file connected to an arithmetic and logic unit by a first bus and a second bus via a barrel shifter. The output of the arithmetic and logic unit is connected to the register by a third bus. A Booth Finite State Machine (FSM) is connected to the first bus. A partial product is realigned with respect to an operand A and an Arithmetical Shift Right (ASR) according to the following relation: product=ASR (product, align).+-.operand.sub.-- A. The cycles of a second type ar repeated until the partial product has been shifted by a number of bits corresponding to the desired subword position. Cycles of a first type are performed, such as to obtain, with respect to a Logical Shift Left (LSL), the relation: product=product.+-.LSL (operand.sub.

Abstract: A multi-layered, high performance integrated circuit package is disclosed having a number of design features which increase the performance and manufacturability of the integrated circuit package, and reduce the effects of parasitic noise generated within the package. The metallic layers connecting contact fingers formed on ledges around the periphery of a die cavity area, to their respective package pins are organized such that a ground metallic layer is interposed between each pair of input/output signal metallic layers, and each input/output signal metallic layer is sandwiched between a pair of metallic layers wherein one layer of the pair is connected to a voltage supply and the other layer of the pair is connected to a corresponding ground reference.

Abstract: In a text mode of a display controller, for each character of the text, a plurality of multiple-byte words are stored in a memory buffer. Each multiple-byte word contains an ASCII character code for the character, font attribute information for the character and at least one font line for the character. For each character font line to be displayed on the monitor, a multiple byte word is read. The attribute information and a first character font line are extracted from the multiple byte word. The display controller then constructs a character scan line for the character based on the attribute information and the first character font line. The character scan line may then be displaying on the monitor.

Abstract: A PLL based microprocessor whose frequency may be adjusted by using a microprocessor clock control circuit. The microprocessor clock control circuit comprises a circuit for providing a slew rate limited overdampened PLL that continuously seeks a new frequency, a circuit for selecting a current target frequency for the microprocessor, a circuit for comparing the current target frequency to the current frequency setting of the microprocessor, and a circuit for adjusting the current frequency setting of the microprocessor to match the current target frequency.

Abstract: An integrated circuit is tested when input/output pads of the integrated circuit are unconnected to any external device. In order to do this, for each of a subset of the unconnected input/output pads, a boundary scan register is provided. A test vector is scanned serially into the boundary scan registers. The test vector may then be applied to internal logic of the integrated circuit. While the test is in progress, the value contained within each boundary scan register is applied to an associated input/output pad so that, as a result, the test vector is applied to the subset of the unconnected input/output pads.

Abstract: A method of commonizing the pattern density of topography for different layers of semiconductor wafers to improve the Chemical Mechanical Polishing process used during wafer processing is disclosed. In order to achieve a predetermined pattern density of topography on the surface of a wafer, dummy raised lines are inserted as necessary into gaps between active conductive traces on a trace layer. In some embodiments, the predetermined pattern density is in the range of approximately 40% to 80%. In some applications, both the active conductive traces and the dummy raised lines are formed from a metallic material that is deposited in one single step with an insulating layer deposited over both the active conductive traces and the dummy raised lines prior to the Chemical Mechanical Polishing process. In other applications, the dummy raised lines are formed from the insulating layer.

Abstract: An integrated circuit structure including a conductive layer, a first dielectric layer overlying the conductive layer, a second dielectric layer overlying both the first dielectric layer and the conductive layer and a planarizing layer overlying the second dielectric layer. The conductive layer has a lateral dimension which is greater than a corresponding lateral dimension of the first dielectric layer. Thus the conductive layer and the first dielectric layer form a stepped, pyramidal shaped island. As a result of the stepped, pyramidal shape, the overlying planarizing layer forms with a more planar upper surface than if the sidewall of the island had a vertical profile. In one preferred embodiment of the present invention, the conductive layer is formed from tungsten-silicide, and both of the dielectric layers are either silicon dioxide or silicon nitride.

Abstract: A scan flip-flop includes a data input, a scan input, a mode selection input, a mode control input and a clock input. When the mode selection input is set to a first selection value, and the mode control input is set to a first control value, the scan flip-flop operates as a D flip-flop. When the mode selection input is set to a second selection value, the scan flip-flop shifts in a scan input value on the scan input when one of the mode control input and the clock input is toggled. Also, as long as the mode selection input is set to the first selection value, and the mode control input is set to a second control value, the scan flip-flop holds a current value within the scan flip-flop.

Abstract: The technique of redundantly retransmitting digitized voice data on multiple sequential frequencies increases the channel bit rate above the minimum required for normal communication in a frequency-hopping communication system for digitized voice signals. Digitized voice data is redundantly retransmitted on multiple sequential frequencies and the channel bit rate is increased above the minimum required for normal communication. Repeated transmissions of the same block of digitized voice data occurs n times at n times the bit rate of the original digitized voice data. A frequency-hopping transmitter transmits on different channels, or carrier frequencies, which are modulated by the digitized voice data signals from a transmitter data buffer. A receiver data buffer holds n blocks of digitized voice data.

Abstract: A resistor formed in a well adjacent to a transistor serves as a ballast resistor for the transistor. The transistor is formed in a first region on a substrate. The first region is of a first conductivity type. A well of second conductivity type is formed adjacent to the first region. A gate region is formed over a portion of the first region. Concurrently, a covering is formed over a first area of the well. The covering and the gate region are comprised of the same material. Source/drain regions of the second conductivity type are formed on either side of the gate region. The source/drain regions are of the first conductivity type. A first source/drain region extends into the well. Concurrent to the forming of the source drain regions, a doped region is formed within the well. The doped region and the first source/drain region have the same doping density. The doped region is physically separated from the first source/drain region by the first area of the well.

Abstract: The present invention discloses a method and an apparatus for making digital integrated circuits by considering ramp delay and clock skew as constraints while minimizing the number of inserted buffers and overall wire length connecting components for large clock trees. The invention includes developing a set of circuit specifications including maximum clock skew, minimum driveability, and maximum ramp delay. These specifications are described in a hardware description language on a digital computer system, and a netlist is synthesized from this hardware description. A modified netlist is then formed by analyzing the netlist and inserting buffers into it to satisfy the circuit specifications of skew, driveabilility, and ramp delay. Thereafter, a digital integrated circuit is produced as specified by the modified netlist.

Abstract: A method for removing the critical false paths takes place during logic optimization. It is based on a path-constrained redundancy removal algorithm. This path-constrained redundancy removal algorithm automatically finds that a path node does not affect the behavior of the path output and so determines a critical path. This method is iteratively repeated for as long as this critical path is false.

Abstract: A purge head is provided for use with an integrated circuit test system to direct purge gases, such as nitrogen, to a circuit board on which a device under test is mounted while the device is subjected to below freezing temperatures. The purge head fits into the inner ring or aperture of the product load board to dispense the purge gases directly onto the circuit board on which the device under test is mounted to prevent moisture buildup during cold testing of the device under test.

Abstract: An IC wafer containing thin oxide is fabricated to include at least two differentially-sized plate areas that may be upper plates of capacitors, or gates of associated MOS transistors. Before testing, the thin gate oxide underlying these plate areas is intentionally stressed by applying a stress current between these plates and the substrate. The stress current magnitude is scaled to the plate area such that each plate sees a substantially constant current density. Because weak oxide defects occur somewhat uniformly throughout the thin oxide, a larger plate or gate will overlie more weak oxide defects than will a plate or gate. If wafer test leakage current between the larger plate or gate and substrate exceeds leakage current between the smaller plate or gate and substrate, weak oxide is indicated because the defect is area dependent. By contrast, charge-induced damage is substantially independent of the areas of the plates or gates, due to the scaling of the stress-inducing currents.

Abstract: CPU system performance is improved by reducing the time required to complete a DRAM access by microprocessors such as the 386DX, 386SX and 80286 by incorporating a programmable DRAM controller therewith which permits consecutive DRAM accesses to average N+0.5 processor wait states. The half wait state average is obtained by forcing the system CPU to measure wait states in processor clock time units which are twice the period of an independent clock in the DRAM controller which, in turn, triggers RAS and CAS assert and de-assert. RAS or CAS is thus able to assert 1/2 processor clock period earlier in one memory cycle relative to the last. Early assert time also provides for an early de-assert time so that data can be transferred to/from the DRAM more quickly than previously possible.

Abstract: Process for the processing of logic function specification data of an associated specific integrated circuit or ASIC for a graphical representation of said circuit. The process consists of associating with the specification data Boolean attributes as a function of aspects, characteristics and details which a user wishes to know with respect to the circuit and then constructing data representative of said characteristics. One representation of the circuit can then be displayed by associating graphical symbols with the constructed data.