Abstract: A testing apparatus is integrally formed on a microelectronic integrated circuit chip for testing a plurality of memories including parallel outputs having a total of a first number of bits. The apparatus includes an input unit for writing test data into the memories, a parallel output bus having a second number of bits which is smaller than the first number of bits, and an output unit for selectively connecting outputs of the memories to the output bus such that a total number of bits of the selected outputs is not greater than the second number of bits. The outputs of the memories are connected to the output unit in groups, and the output unit is configured to selectively connect the groups of outputs to the output bus in response to respective control signals to read test data out of the memories. Data is applied from the memories to the output unit in bytes.

Abstract: A semiconductor device assembly utilizing a grid array of conductive epoxy for connecting it to an electronic system. Conductive epoxy is screen printed in a desired pattern onto a printed wire board of the semiconductor device assembly. The conductive epoxy is B-staged by heating in an oven. The semiconductor device assembly is then placed onto a system printed circuit board wherein the B-staged conductive epoxy is further cured by heat and effectively makes mechanical and electrical connections between the semiconductor device assembly and the system printed circuit board.

Abstract: Fine, sub-micron line features and patterns are created in a sensitized layer on a semiconductor wafer by a source of X-ray radiation. The X-ray source emits very low wavelength radiation along a path towards a sensitized surface of a semiconductor wafer. An image mask substrate is disposed in the path of the radiation, and is provided with a patterned opaque material on a surface of a substrate thereof. The substrate is formed of beryllium, which is robust and has a thermal coefficient of expansion closely conforming to that of common image mask carriers. Further, a wide variety of opaqueing materials adhere well to the beryllium substrate, and the substrate is relatively insensitive to moisture. The image mask is spaced sufficiently close to the wafer that radiation passing through the mask forms a corresponding pattern in the surface of the wafer. For X-ray radiation, the opaqueing material is gold, tungsten, platinum, barium, lead, iridium, rhodium, or the like.

Abstract: A methodology for generating structural descriptions of complex digital devices from high-level descriptions and specifications using a systematic technique to map and enforce consistency of the semantics imbedded in the intent of the original, high-level descriptions. The design activity is essentially a series of transformations operating upon various levels of design representations. At each level, the intended meaning (semantics) and formal software manipulations are captured to derive a more detailed level describing hardware meeting the design goals. Important features of the methodology are: capturing the users concepts, intent, specification, descriptions, constraints and trade-offs; architectural partitioning; what-if analysis at a high level; sizing estimation; timing estimation; architectural trade-off; conceptual design with implementation estimation; and timing closure.

Abstract: An automatic logic-model generation system operates on a behavioral description of an electronic design (e.g., a circuit, a system, etc.) to automatically generate a low-level (i.e., circuit-level) design of the electronic design, to lay out the electronic design for production in the form of an integrated circuit, and to produce logic-level models incorporating accurate timing (and delay) information. A verification process is also performed whereby the logic-level model is automatically verified for accuracy.

Abstract: A low-cost high-performance technique for providing bit-mapped graphics display controllers is described whereby video frame buffer memory and video controller functions are integrated together on a single chip, permitting very wide video memory formats without the usual penalties of high pin count, package count, and wiring complexity. The wide video memory format relaxes timing requirements on the video frame buffer memory and provides greater accessibility of the video frame buffer memory for pixel data accesses other than display refresh accesses.

Abstract: The present invention relates to a method of and system for reducing the drive requirements for the input and output pads of an integrated circuit die. An intermediate structure is added between the output connection pad and substrate to reduce the amount of electron charge required to charge the output pad capacitance to a substantially negligible amount. In addition, an intermediate structure my be added between an input connection pad and substrate to reduce the amount of electron charge required to charge the input pad capacitance to a substantially negligible amount. The present invention connects a transistor amplifier driver to the intermediate structure between the output pad and substrate to charge the capacitance that exists between the intermediate structure and substrate so that the voltage potential of the intermediate structure is substantially the same value as the output pad voltage value.

Abstract: An efficient technique or providing ROM memory on a microprocessor local bus is described whereby a ROM and all necessary address decoding and control circuitry is incorporated in a single integrated circuit. By doing this, only one chip is required to add ROM to a microprocessor local bus, saving considerable space and power over discrete implementations. The ROM is implemented in a wide memory format, matching the bus width of the microprocessor to which it is connected. This permits full-speed access to the local bus ROM, and eliminates any need for such techniques as ROM "shadowing".

Abstract: A microelectronic circuit includes a plurality of circuitry blocks and sub-blocks, a clock driver, an electrical interconnect that directly connects the clock driver to the sub-blocks, and balanced clock-tree distribution systems provided between the electrical interconnect and circuitry in the sub-blocks respectively. A method of producing a hierarchial clock distribution system for the circuit includes determining clock skews between the clock driver and the sub-blocks respectively. Delay buffers are selected from a predetermined set of delay buffers having the same physical size and different delays, with the delay buffers being selected to provide equal clock skews between the clock driver and the distribution systems respectively. Each delay buffer includes a delay line, and a number of loading elements that are connected to the delay line, with the number of loading elements being selected to provide the required clock delay for the respective sub-block.

Abstract: The present invention provides a method for fabricating an integrated circuit package, as well the resulting integrated circuit package, which retains a heatsink in close communication with a mold cavity. This precludes any encapsulant from flowing between the heatsink and the inner surface of a mold cavity. As a consequence, the bottom of the heatsink is not encapsulated and is thus exposed. This is accomplished by including posts, attached to the leadframe assembly, which have the function of exerting a downward force on a leadframe assembly and, in turn, on the heatsink. Tie bars, which are non-functional parts of a leadframe assembly, can be utilized as posts by bending the posts into an upright position.

Abstract: A semiconductor die having raised conductive bumps on its surface for connecting to other devices or systems is disposed on a face of a preformed planar structure (interposer) having through holes. Solder joints with conductive bumps on an underlying substrate are formed in the through holes. In one embodiment, the interposer is dissolvable. In another embodiment, the through holes are at least partially filled with a conductive material for electrically connecting to the die. In another embodiment, the through holes are angled so that the interposer acts as a pitch spreader or adapter. In another embodiment, ball bumps are disposed on a side of the interposer away from the die. Various other embodiments are directed to multi-tier flip-chip arrays employing preformed planar structures between tiers.

Abstract: A removable heatsink assembly comprised of a heatsink unit and a heatspreader is provided. The heatsink unit has at least one fin and a coupling collar for radiating heat away from a packaged electronic device. The heatspreader includes a platform attached to an inner collar in thermal contact with the packaged electronic device. The platform has one or more tabs suitable for mating with one or more flanges located on the coupling collar of the heatsink unit. Coupling grooves within the flanges engage the platform of the heatspreader when the flanges are mated with the heatspreader tabs and the heatsink is turned. The heatsink can therefore be quickly and conveniently attached to or removed from the heatspreader. The present invention thus permits a wide variety of different heatsinks to be interchangeably used with a single heatspreader attached to an electronic device package.

Abstract: The present invention is an improved method and apparatus for selecting and replacing a block of a set of cache memory. The present invention provides for the weighted random replacement of blocks of cache memory by assigning indices to the memory blocks of a given set of cache memory. One of the assigned indices is then randomly selected by the present invention. The memory block of the given set to which the randomly selected index is assigned is replaced. The indices are assigned such that one or more blocks of the given set of cache memory have a high probability of replacement, whereas the other blocks of the given set of cache memory have significantly lower probabilities of replacement.

Abstract: Fine, sub-micron line features and patterns are created in a sensitized layer on a semiconductor wafer by a beam of Gamma-radiation. A continuous stream of such radiation, such as provided by a pellet of Cobalt-60, is collimated into a fine beam by a tapered collimator, and is gaged on and off by a shutter mechanism comprising a distortable-surface device and a beam-blocking device. The fine, collimated beam converts points in a gamma-radiation-sensitive layer on a semiconductor wafer. By moving the wafer relative to the beam (or vice-versa), patterns are created in the layer of radiation-sensitive layer for further processing a layer underlying the radiation-sensitive layer.

Abstract: A system for modeling and estimating crosstalk noise and detecting false logic is provided. The noise is caused by culprit signal nets that are in a switching state and affect a victim net which is in a non-switching (DC) steady state. This estimated noise is evaluated against a predetermined threshold to determine whether any false logic results in the victim net.

Abstract: A technique for reducing thermally-induced mechanical stresses on bond pads in semiconductor device assemblies is accomplished by grouping (laying out) the bond pads in two parallel rows, approximately centered about a central axis of the die. Further, the bond pads of one row are axially offset from the bond pads of the other row, thereby forming a two-row zig-zag linear configuration of bond pads. The "axis" is a line preferably passing through a thermal centroid of the die. By keeping the bond pad layout close to the axis, lateral thermally-induced displacements of the bond pads relative to the axis can be minimized and controlled. Longitudinal (axial) displacements of the bond pads are accommodated by flexing, rather than compression, of conductive lines (such as leadframe fingers) connecting to the bond pads and entering the die perpendicular to the axis.

Abstract: A method of cell placement for an integrated circuit chip includes performing a contraction operation by which at least some of the cells are relocated to new positions that provide lower interconnect wirelength. For each cell, the centroid of the net of cells to which the cell is connected is computed. The cell is then moved toward the centroid by a distance that is equal to the distance from the current position of the cell to the centroid multiplied by a "chaos" factor. This process continues until a specific energy condition is met; then the `expansion` mode is entered. An expansion operation is then performed by which the net force exerted on each cell by other cells in the placement and a resulting altered velocity of the cell are calculated, and a new cell position is calculated based on the altered velocity over an incremental length of time. The system stays in expansion mode until another energy criterion is met.

Abstract: A polysilicon interconnect is formed on a microelectronic circuit substrate for conducting signals from a driver to a non-polycrystalline silicon contact which has higher impedance than the interconnect. A plurality of electronic "speed bumps" are spaced along the interconnect for disturbing or disrupting signals propagating along the interconnect toward the contact and thereby reducing undesirable back reflection and ringing. The speed bumps can include capacitance altering elements in the form of dielectric strips, or resistance altering elements in the form of low resistance doped areas or high resistance amorphous areas. The speed bumps can include first and second elements having different values of capacitance or resistance which are spaced along the interconnect in alternating relation.

Abstract: Composite bond pad structure and geometry increases bond pad density and reduces lift-off problems. Bond pad density is increased by laying out certain non-square bond pads which are shaped, sized and oriented such that each bond pad closely conforms to the shape of the contact footprint made therewith by a bond wire or lead frame lead and aligns to the approach angle of the conductive line to which it is connected. Alternating, interleaved, complementary wedge-shaped bond pads are discussed. Bond pad liftoff is reduced by providing an upper bond pad, a lower bond pad and an insulating component between the upper and lower bond pads. At least one opening is provided through the insulating component, extending from the bottom bond pad to the upper bond pad. The at least one opening is aligned with a peripheral region of the bottom bond pad and is filled with conductive material.

Abstract: An integrated circuit layout technique is described which employs an optimization-driven clustering technique to provide improved cell placement. The technique utilizes clustering of cells based upon Rent's rule, with global-optimization-derived inter-cell distances being used to break ties when identical Rent exponents are encountered. A constraint on the number of cells permitted to be in a cluster and a constraint on the maximum Rent exponent which to be considered for merging clusters minimize the "overgrowth" of clusters and serve to even out cluster size, ideally suiting the technique to conventional partitioning and placement schemes.