Abstract: A bounds checker consisting of a pair of comparators that each compare a 16-bit number with a lower and an upper limit stored in registers. The device is preferably constructed as a single integrated circuit chip employing emitter coupled logic (ECL) circuitry and can be made externally compatible with either transistor transistor logic (TTL) circuitry or ECL circuitry. The device can be cascaded to operate on extended-precision numbers and has a pin which can be used to select comparison of numbers either as signed two's complement numbers or as unsigned numbers. No added gate delay is imposed by the device's ability to operate either type of number.

Abstract: A single-chip microprogrammable sequence controller includes a subroutine stack and conditional branching facilities. The controller performs a test and mask operation followed by comparison with a user-defined constant to effect a Boolean sum-of-product function. Address control logic includes a flag signal set by compare logic; the flag is available to a microinstruction decoder where it can be used during a subsequent conditional branch operation based on the setting of the flag.

Abstract: An ECL circuit comprising an output transistor having a base, a resistor coupled to the base, a first circuit responsive to a deselect signal OE for drawing a first current through the resistor and a second circuit responsive to the deselect signal OE for drawing a second current through the resistor, said first and said second currents combining in said resistor for providing a predetermined turn-off bias potential on said base of said output transistor. The predetermined turn-off bias potential reduces the emitter current of the output transistor such that the noise immunity of a data bus is preserved when a plurality of output transistors are coupled in parallel to the data bus.

Abstract: An improved bipolar slot transistor vertically formed in a slot in an integrated circuit structure is disclosed. The transistor is formed in a substantially vertical slot having an active base region formed beneath the bottom of the slot and comprises an active collector region formed beneath the active base region, a buried collector layer beneath the active collector region and in communication with a collector contact; an emitter region formed in the slot over the active base region; and extrinsic base regions formed adjacent to but insulated from the sidewalls of the slot communicating with the active base region and with base contact regions on the surface of the structure.

Abstract: A single-chip fixed/floating-point arithmetic processor, a three port ALU, a plurality of storage registers R, S, F0 and F1, a constant store circuit and an output data register F. Two of the storage registers R and S are provided for storing 64-bit input operands and two of the regusters F0 and F1 are provided for storing 64-bit results of operations performed in the ALU. Each of the registers are provided with three output ports and corresponding pass gates for selectively transferring data from the registers to the three inputs of the ALU under the control of control signals applied to the pass gates. The constant store is also coupled to one of the input ports of the ALU by a pass gate for transferring constants to the ALU under the control of a pass gate. Results of the ALU are provided to the data output register F for further processing off-chip.

Abstract: A compact rectangular parallel multiplier array of Booth summation cells includes along a left edge a cell which reduces to two the number of sign-extension bits sufficient to generate subsequent intermediate products. The cell employs optimized logic circuitry which generates a sum, a carry and a guard bit for use during generation of the next most-significant intermediate product.

Abstract: The present invention provides for a method for manufacturing a charge storage region in a semiconductor substrate for a memory cell in a dynamic RAM, comprising forming an insulating layer on the substrate, forming a masking layer over the insulating layer, forming at least one aperture in the masking layer, the aperture defining the charge storage region in the semiconductor substrate, implanting dopant ions of a first polarity through the aperture for diffusion through the substrate, and implanting dopant ions of a second polarity through the aperture for diffusion through the substrate to a lesser degree than the first polarity dopant diffusion so that the diffusion of the first polarity dopant with respect to the diffusion of the second polarity dopant forms a P-N junction substantially aligned with the edge of the masking layer aperture to define the periphery of the charge storage region.

Abstract: An improved method of making a bipolar transistor is disclosed which comprises forming one or more mask layers over a silicon substrate, etching at least one of said one or more masking layers to define a base contact area and a spaced apart collector contact area with an unetched emitter contact area defined in-between, forming a collector slot in a substrate of an integrated circuit structure through the collector contact area defined in the one or more mask layers, oxidizing the sidewall of the collector slot, filling the collector slot and the base and collector contact regions with polysilicon, removing one or more of the mask layers between the polysilicon base and collector contacts, oxidizing the exposed sidewalls of the polysilicon base and collector contacts, forming an emitter contact region between said collector and base contact regions insulated from the base and collector contacts by the sidewall oxidation thereon, and forming a base region in said substrate spaced from the collector slot by th

Abstract: An ECL circuit comprising an output transistor having a high output voltage VOH guard band and a low output voltage VOL guard band with a temperature compensating network coupled to the output transistor for causing the high level output voltage VOH and low level output voltage VOL of the output transistor to remain within the maximum and minimum limits of the VOH and VOL guard bands over a wide temperature range.

Abstract: An adjustable sense amplifier circuit for read/write control of solid state memory devices is described. In a write mode the circuit includes a write select path, coupled to a current source and coupled to a differential pair of data select transistors, wherein the input data state sets each of two differential pairs formed by the memory element cross-coupled latch, such that the memory element stores selected data. In a sense mode, a second current path is selected wherein an adjustable sense level is provided to each of two differential pairs formed by the memory element. The current source is coupled to a reference voltage source which is independent of the supply voltage. The reference voltage source tracks changes in temperature and also provides low beta compensation for current loss due to the low beta value of transistors in the write and sense paths.

Abstract: There is disclosed herein a servo data decoder which can decode both quadrature and non quadrature servo data. The decoder is comprised of a servo data amplitude demodulator to generate position error signals and a position error signal processor to generate a GPES signal to serve as a position error signal during the track following mode and a velocity signal and a track crossing signal for use in the seek mode. The user system may have either single or double pulse sync, and double pulse sync spacing, pulse window time and sync to first data pulse delay are user definable. The user may adjust the gain of the system in two manners and may program the frequency response characteristics of the phase locked loop. Many other user definable or user alterable features are provided.

Abstract: A tag buffer having built-in testing capabilities is disclosed. In a single-chip, integrated-circuit design which includes a SRAM, a parity generator and checker, and a comparator, a method and capability of testing the functionality of the SRAM and parity components is defined. For an embodiment in which the SRAM component includes a redundancy scheme for replacing a defective memory array row, a test for determining whether a redundant row has been used is also provided.

Abstract: Three-level ECL or four-level CML are feasible when a low drop current source is incorporated in the series-gated arrangement. The low drop current source consumes less than one-tenth of the voltage span between V.sub.CC and ground. A greater portion of the voltage span between V.sub.CC and ground, up to 4 volts, is therefore reserved for the three ECL levels or four CML levels of logic. Conventional power supplies are utilized yet the number of logic functions is increased.

Abstract: An improved integrated circuit structure is disclosed which comprises a Vcc bus and a Vss bus having capacitance means coupled between the busses and distributed along the length of the busses to reduce the voltage spikes induced during switching. In a preferred embodiment, the capacitance means comprise one or more capacitors formed beneath one of the busses. Construction of MOS capacitors beneath one or more of the busses is disclosed.

Abstract: A bias generator for use in CML gate circuits provides an output reference voltage that is substantially independent of variations in supply voltage over a wide temperature range. The bias generator includes a temperature and voltage compensating circuit portion which is formed of an emitter resistor and a diode-connected transistor. The emitter resistor is used to control the output reference voltage for the lower temperatures and the base-emitter voltage of the transistor determines the output reference voltage for the higher temperatures.

Abstract: Method and apparatus suitable for inclusion in an integrated circuit transceiver meeting IEEE 802.3 standards which detects "collisions" so that more than one station will not simultaneously transmit over a network. The method employs a novel three-pole cyclical low-pass filter which attenuates the ac component received over the network to less than 20 mV to allow collision detection within the 900 nanosecond budget allowed by the IEEE standard. A differential operational amplifier receives the signal from the network and a collision reference voltage. The signal generated by the differential amplifier is filtered by the low-pass filter and then coupled to a high-gain comparator which acts as a zero-crossing detector. The comparator generates ECL logic signals representing the occurrence or non-occurrence of a collision. The resulting collision detector operates over a wide range without the need for field "trimming".

Abstract: A simple architecture to implement a mechanism for performing data references to storage in parallel with instruction execution. The architecture is particularly suited to reduced instruction-set computers (RISCs) and employs a channel address register to store the main memory load or store address, a channel data register which temporarily stores the data from a store operation and, a channel control register which contains control information including the number of the register loaded within the file, in the case of a load operation. This number is used to detect instruction dependency of the data to be loaded. Logic circuitry suspends further instruction processing if the data required from a load is not yet available. A data-in register is used to store load data until an instruction execution cycle is available for writing it back to the register file. Logic circuitry detects storage of data prior to its writing back, so as to effectively replace the register file location.

Abstract: A bipolar transistor susceptible to high level integration has its active regions formed in slots within a semiconductor substrate. In one embodiment, the emitter is formed within a slot and has a surrounding region doped to function as a base. A collector is formed in another slot which is located adjacent but spaced apart from the emitter slot. Carrier transport occurs principally horizontally between the emitter and base and then to the collector. Additional slots may be used to isolate the slot transistor in conjunction with a horizontally disposed pn junction and a buried collector. The collector may be formed in a slot which contains an oxidized outer sidewall that serves to isolate the individual transistor.

Abstract: A hysteresis circuit is disclosed in which a first signal path, including a hysteresis feedback loop, is separate from a second signal path that is used to carry data. When the signal input to the hysteresis circuit (also referred to hereinafter as the "input signal") crosses a first preselected hysteresis reference of ("threshold") level, the hysteresis feedback loop, which includes threshold adjustment means, will cause a change in the threshold from the first preselected level to a second preselected level. This adjustment of threshold level will take place in parallel with the data being propagated to the output over said separate second signal path. A subsequent crossing of the second preselected threshold level by said input signal will cause the first threshold level to the reset and so on.

Abstract: A static PLA circuit includes a logic gate portion, a precharge circuit portion and a feedback circuit portion. The feedback circuit portion is connected between the output of the logic gate portion and the input of the precharge circuit portion. The feedback circuit portion functions to delay the turn-on time of the precharge circuit portion when the output of the logic gate portion is making a high-to-low transition, thereby increasing the speed of the output transition.