Abstract: Disclosed is a method for making a shallow trench structure in a semiconductor substrate. The method includes: (a) forming a mask over a semiconductor substrate, the mask being provided with an aperture extending therethrough which exposes a region of the semiconductor substrate, the aperture having substantially vertical sidewalls; (b) depositing a blanket of silicon over the mask and within the aperture; (c) anisotropically etching the deposited silicon to form temporary spacers having curved profiles at the sidewalls of the aperture, the temporary spacers transferring the curved profiles to a mouth of a shallow trench being etched at the region of the semiconductor substrate as the temporary spacers are etched away; (d) whereby a shallow trench structure is formed where the mouth has a curved profile.

Abstract: A method for maximizing the performance versus the power consumption of a computer system. The method uses a CPU which has the ability to select an optimum external to internal clock frequency ratio. By changing the external to internal clock frequency ratio, the computer system is able to decrease the internal clock frequency in order to conserve power, while allowing the external clock frequency to be at an optimum level in order to maintain maximum system performance.

Abstract: A metastableproof flip-flop receives an input value on a flip-flop input. The flip-flop holds an output value on a flip-flop output. In response to a transition of a clock signal, a transition in the output value occurs. The new output value is the input value formerly received by the flip-flop. In order to make the flip-flop metastableproof, the transition in the output value is delayed when the input value is in a metastable state. When the input value is no longer in the metastable state, then the transition in the output value is allowed to complete.

Abstract: Disclosed is a method for programming an antifuse structure. The antifuse structure is programmed by applying an alternating current having alternating current pulses between a bottom and a top electrode to generate a conduction path through an antifuse material sandwiched between the electrodes. The conduction path is formed incrementally due to an electron flow produced as a result of each alternating current pulse thereby defining the conduction path at a substantially centered portion of the antifuse material.

Abstract: A computer aided design system converts system level timing constraints to the minimum number of path-based timing constraints necessary to represent the same timing constraints as the system level timing constraints. Using a data structure for each node of the circuit, signal arrival times and required arrival times for each node are generated for each high level timing constraint, and the worst slack time is identified for each node. Then, a node with a worst slack time is selected, the constraint associated with that worst slack time is identified, and then a worst case path from a start node of the identified constraint through the selected node to an end node of the identified constraint is determined. The start and required signal arrival times associated with the identified constraint's start and end nodes in the determined path are also identified.

Abstract: The present invention relates to an apparatus and method for supporting DMA I/O devices on a PCI bus. A DMA I/O device is coupled to a DMA controller via a serial link and two signal lines. The serial link is used by the DMA I/O device to request a DMA transfer. When the DMA controller receives the serialized DMA request, it sends a signal to an arbiter and waits for the PCI bus to be granted to the DMA controller for use during the DMA transfer. When granted the PCI bus, the DMA controller signals the DMA I/O device. The DMA I/O device asserts a signal in response to the one asserted by the DMA controller. The DMA controller recognizes the signal asserted by the DMA I/O device and continues with the DMA transfer. The transfer continues for as long as the DMA I/O device continues to assert the signal or for as long as the DMA controller is programmed.

Abstract: A circuit for producing a buffered output includes a power source, a ground, a circuit input, a circuit output, a voltage reference source, a current control pre-driver and an output driver. The circuit input receives an input signal. The circuit output produces an output signal. The voltage reference source generates a reference voltage. The current control pre-driver includes a first current source, a second current source, and control logic. The first current source is connected to the power source and has a first control input. The second current source is connected to the ground and has a second control input. The control logic is connected to the circuit input, to the voltage reference source, to the first control input of the first current source and to the second control input of the second current source. In response to a first voltage value of the input signal on the circuit input, the control logic turns off the second current source and turns on the first current source.

Abstract: Titanium is deposited using a low-pressure chemical-vapor deposition to provide good step coverage over an underlying integrated circuit structure. A rapid thermal anneal is performed using an ambient including diborane. The rapid thermal anneal causes the titanium to interact with underlying silicon to form titanium silicide. Concurrently, the diborane reacts with the titanium to form titanium boride. A composite barrier layer results. Aluminum is deposited and then patterned together with the composite barrier layer to define a first level metalization. Subsequent intermetal dielectrics, metalization, and passivation layers can be added to form a multi-level metal interconnect structure. The titanium boride prevents the aluminum from migrating into the silicon, while the titanium silicide lowers the contact resistivity associated with the barrier layer. The relatively close match of the thermal coefficients of expansion for titanium boride and silicon provides high thermal stability.

Abstract: The present invention relates to a system and method for securing sensitive data on mass storage devices. The system and method use an encryption device to encrypt sensitive data that is to be stored on the mass storage devices. A plurality of cryptographic keys are provided to ensure that only authorized personnel have the ability to access the encrypted data.

Abstract: A digital phase shifter phase shifts an input signal by a predetermined phase angle. A length of a cycle of the input signal is determined. Then an output signal is generated which is phase delayed from the input signal by a phase amount. The phase amount is approximately equal to the length of the cycle of the input signal multiplied by the predetermined phase angle.

Abstract: A liquid level monitor uses a tube to confine a float to a vertical path with a canister containing a lower liquid and an upper liquid which meet at a liquid boundary, the level of which is to be monitored. Light from a light-emitting diode is conveyed to a vertical position of the tube by an optical fiber. A second optical fiber is arranged in a diametrically opposed position of the tube to detect light transmitted across the tube from the first optical fiber. The float is more transmissive than either liquid. When the level of the boundary falls to the level of the optical fibers, received light increases. The second optical fiber conveys this return light to a photodetector, the output of which can be used to trigger an alarm indicating that the boundary level is low.

Abstract: A method for making an integrated circuit characterized by: determining a range of bonding pad pitches which varies between a minimum bonding pad pitch and a maximum bonding pad pitch; setting a driver pitch to the minimum bonding pad pitch; forming a base set including a plurality of drivers having the determined driver pitch; forming customization layers over the base set, where the customization layers include a plurality of bonding pads having a pad pitch greater than the minimum bonding pad pitch but less than or equal to the maximum bonding pad pitch; and coupling some, but not all, of the drivers to the pads. As a result, a single base set can be used to make integrated circuits having a range of bonding pad pitches. The method and structure of the present invention are very well adapted for use in gate array integrated circuits.

Abstract: A system is provided for digitizing the setting of a potentiometer of the type used in an analog joystick for computer games. The analog output of the potentiometer is applied to one of two inputs of a voltage comparator. When a readout of the joystick position is desired, a "write" input is applied to a counter to permit it to commence counting at a predetermined frequency from an initial or zero count. The digital outputs of the counter are coupled to the inputs of a digital-to-analog converter, the output of which is coupled to the second input of the voltage comparator. When the count in the counter produces a voltage at the output of the digital-to-analog converter corresponding to the voltage setting of the potentiometer, the comparator provides an output signal. The time delay from the time the write pulse occurs until this signal is obtained is representative of the potentiometer setting.

Abstract: The present invention relates to a system and method for passing Industry Standard Architecture (ISA) legacy interrupts across Peripheral Component Interconnect (PCI) connectors. The system interconnects a plurality of PCI devices coupled to a PCI bus such that a last interrupt pin of each of the plurality of PCI devices are coupled together in a directly bussed manner to provide a serial interrupt signal line. The remainder of the interrupt pins of each of the plurality of PCI devices are coupled together in a barber pole manner.

Abstract: A system for testing a digital counter of mn stages, in which the counter is organized into m segments, each of n bits, includes a two input exclusive OR gate connected between each of the m segments. One of the two inputs of each exclusive OR gate is obtained from the carry output of a lower order one of the m segments, and the output of each exclusive OR gate is connected to the carry input of the next higher order one of the m segments. The other inputs to the exclusive OR gates are obtained from a test signal enable input, which is driven high (binary "1") for the test mode of operation. The counter is fully exercised in the test mode in a parallel operation, with full testing of the carry bits from one segment to the next, without any interruption in the clock signal input stream.

Abstract: A link system controller is interposed between a PCI bus and the CPU data bus and memory data bus of a personal computer system to ensure that the transfer of data from the PCI bus to the CPU data bus occurs on different clock signals from the transfer of data from the PCI bus to the memory data bus. This is accomplished by an authorizing circuit, which alternately enables a CPU bus interface controller and a memory data bus controller in response to alternating clock signals. This prevents simultaneous switching of the devices on both the CPU data bus and the memory data bus, to reduce the generation of noise below an acceptable threshold; so that the operation of the IC system device is not impaired.

Abstract: A method and system are designed to guarantee availability of ownership of an ISA bus by a bus mastering or a direct memory access device in a system also including a PCI bus. This is accomplished by placing a lock on the PCI bus through a bridge device to a configuration read of a PCI configuration space register. Once the lock is established, other PCI devices are prevented from locking any other resource on the PCI bus. The PCI configuration space exists outside of the memory or I/O ranges to which an ISA resident device can generate access. Consequently, whenever the ISA resident device generates its access, it is to a device known not to be in a locked state. Consequently, the bus transaction is capable of completion within the time limit expected by the ISA resident device.

Abstract: An integrated circuit package of this invention includes a series of nonconductive rigid substrates, each substrate having a pattern of generally coplanar bond fingers embedded thereupon. An integrated circuit die is connected to individual bond fingers of varying bond finger patterns. Individual bond fingers are connected to package terminals by medial leads, which are generally perpendicular to the bond finger patterns. Semiconductor die packages having both top and bottom package terminals are thus produced. Methods and devices are shown.

Abstract: Forming tungsten plugs allows for a conformal step coverage into contacts in semiconductor wafer processing. By rinsing the wafers after the tungsten etchback but before the wafers have a chance to enter an oxygen-containing environment, the amount of fluorine-containing residue removed from the wafer can be increased. In this way, the connection between the tungsten plugs and a metallization layer can be improved.

Abstract: An interrupt based positioning system for a joystick. A potentiometer is coupled to the joystick for supplying a voltage signal representative of a current position of the joystick. An analog-to-digital converter changes the voltage signal to a digital voltage signal which is then stored in a register. Interrupt generation logic monitors the output of the register and generates a position interrupt signal when the digital voltage signal stored in the register indicates a change in the axial position of the joystick.