Abstract: A digital data signal capture circuit for synchronization of received digital data signals includes a transition detector for determining a state transition of the received digital data signal. The transition detector samples the received digital data signal at a first time, a second time and a third time and determines whether the transition occurs between the first time and the second time and whether it occurs between the first time and third time and generates an increment/decrement signal indicating a position for the transition. A strobe adjust circuit generates a strobe signal based on the increment/decrement signal. A capture circuit captures the received digital data signal using the strobe signal.

Abstract: A synchronous clock signal can be adjusted relative to a data signal by decreasing a delay in the synchronous clock signal if a transition of a data signal occurs before a pulse of an offset clock signal which is delayed by one half cycle relative to the synchronous clock signal. The synchronous clock signal can be delayed if the transition of the data signal occurs after the pulse of the offset synchronous clock signal.

Abstract: In one embodiment, provided is a protocol specific circuit for simulating a functional operational environment into which a device-under-test is placed for functional testing. The protocol specific circuit includes a protocol aware circuit constructed to receive a non-deterministic signal communicated by a device-under-test and to control a transfer of the test stimulus signal to the device-under-test in response to the a non-deterministic signal.

Abstract: In some implementations, a method for testing is provided, which includes simulating a functional operational environment for a first type device-under-test with a tester. This includes recognizing a non-deterministic response signal having a predetermined protocol, receiving the non-deterministic response signal from the first type device-under-test, ascertaining an expected stimulus signal to be transferred to the first type device-under-test from the non-deterministic response signal based on the predetermined protocol, and initiating transmission of the expected stimulus signal to the first type device-under-test. The method further includes simulating a functional operational environment for a second type device-under-test with the tester after testing the first type device-under-test.

Abstract: A calibration device is provided for use with automatic test equipment (ATE). The calibration device includes circuitry having a fanout circuit. The compare-side fanout circuit has an input connected to a first channel of the ATE and outputs connected to N (N>1) channels of the ATE, where the N channels do not include the first channel. The ATE propagates an edge on the first channel, and the fanout circuit transmits the edge to the N channels. Optionally, a calibration device for use with automatic test equipment includes a drive-side circuit. The drive-side circuit includes circuitry having multiple inputs connected to N (N>1) channels of the ATE and an output connected to a second channel of the ATE that is not one of the N channels. The ATE propagates an edge on each of the N-channels and the circuitry propagates each edge to the second channel of the ATE.

Abstract: An apparatus for use in testing a device includes a parametric measurement unit to measure a first signal from the device, and pin electronics to provide a second signal to the device. The pin electronics includes circuitry along a path to the device. The parametric measurement unit is electrically connected to the device via the circuitry to receive the first signal via the circuitry.

Abstract: A calibration device is provided for use with automatic test equipment (ATE). The calibration device includes circuitry having a fanout circuit. The compare-side fanout circuit has an input connected to a first channel of the ATE and outputs connected to N (N>1) channels of the ATE, where the N channels do not include the first channel. The ATE propagates an edge on the first channel, and the fanout circuit transmits the edge to the N channels. Optionally, a calibration device for use with automatic test equipment includes a drive-side circuit. The drive-side circuit includes circuitry having multiple inputs connected to N (N>1) channels of the ATE and an output connected to a second channel of the ATE that is not one of the N channels. The ATE propagates an edge on each of the N-channels and the circuitry propagates each edge to the second channel of the ATE.

Abstract: A channel for use in automatic test equipment and adapted for coupling to a device-under-test is disclosed. The channel includes a driver and respective AC and DC-coupled signal paths. The AC-coupled signal path is disposed at the output of the driver and is configured to propagate signal components at and above a predetermined frequency. The DC-coupled signal path is disposed in parallel with the AC-coupled signal path and is configured to propagate signal components from DC to the predetermined frequency.

Abstract: A test system with easy to fabricate hardware to make measurements on differential signals. The two legs of a differential signal are applied to a comparator. A variable bias is introduced into the comparison operation. By taking multiple measurements with different bias levels, the level of the differential signal may be determined. The time of measurements relative to the start of the signal can be varied to allow plots of the signal to be made. Variability of the signal caused by noise can be measured by collecting sets of data points with the same bias level at the same relative time. Circuitry for introducing bias into the comparison is disclosed that allows measurements to be made with a pre-packaged, commercially available high speed comparator.

Abstract: A signal interface to connect a semiconductor tester to a device under test. The Interface includes a generic component and customized component. The generic component includes multiple copies of electronic elements that can be connected in signal paths between the tester and the device under test. The customized component is constructed for a specific device under test and provides connections between generic contact points on the generic component and test points on the device under test. In addition, the customized component has conductive members that can be used to interconnect the electronic elements on the generic component. The connections configure the electronic elements into signal conditioning circuitry, thereby providing signal paths through the interface that are compatible with the I/O characteristics of specific test points on a device under test. The generic and the customized components may be fabricated on semiconductor wafers.

Abstract: A channel for use in automatic test equipment and adapted for coupling to a device-under-test is disclosed. The channel includes a driver and respective AC and DC-coupled signal paths. The AC-coupled signal path is disposed at the output of the driver and is configured to propagate signal components at and above a predetermined frequency. The DC-coupled signal path is disposed in parallel with the AC-coupled signal path and is configured to propagate signal components from DC to the predetermined frequency.

Abstract: A channel for use in automatic test equipment and adapted for coupling to a device-under-test is disclosed. The channel includes a driver and respective AC and DC-coupled signal paths. The AC-coupled signal path is disposed at the output of the driver and is configured to propagate signal components at and above a predetermined frequency. The DC-coupled signal path is disposed in parallel with the AC-coupled signal path and is configured to propagate signal components from DC to the predetermined frequency.

Abstract: Automatic test equipment implemented with low cost CMOS components. Despite the use of CMOS circuitry, which generally has poor timing accuracy, the disclosed test equipment achieves good timing accuracy through the use of several techniques. A delay locked loop is used to compensate for timing variations caused by process variation and slowly varying changes in operating temperature. A frequency dependent heating element is used to avoid temperature induced changes in propagation delays caused by rapid variations in the heat generated by the CMOS circuitry when the operating frequency changes. The design also reduces the number of circuit elements in the critical timing paths which process signals which vary with programmed frequency. To achieve this goal, a continuously running, fixed frequency reference clock is delayed by a fractional amount of one clock period. A counter, also clocked at the reference clock frequency, counts full clock periods.

Abstract: Automatic test equipment for semiconductor memories that provides testing of large arrays of semiconductor memory chips in parallel. Such massively parallel memory testing greatly enhances test throughput, thereby reducing cost. It greatly enhances the economics of testing memory device made according to a RAMBUS standard, which includes a low speed port and a medium speed port because it allows the same automatic test equipment to economically be used to test devices with the low speed port and the medium speed port.

Abstract: A system for providing a plurality of synchronous timing signals having period values that are not even multiples of the clock period including a plurality of local edge generators receiving the clock signals, each local generator including local programmable means to count clock signals and provide local outputs upon receiving predetermined clock signals and local programmable delay means for providing a timing signal after a delay interval following each local output, the resolution of the local delay means being greater than that of the clock.

Abstract: A bipolar transistor device having reduced collector-base capacitance and advantageous extrinsic base resistance properties is fabricated by a self-aligned process. Successively formed first and second self-aligned masking spacers are utilized to define the collector-base junction area and to permit the conductivity of base link and base contact portions of the extrinsic base to be independently established.

Abstract: A semiconductor PROM contains a group of PROM cells (12) each consisting of a pair of opposing diodes oriented vertically with their common intermediate region (22) fully adjoining a recessed oxide insulating region (16). A composite buried layer consisting of buried regions (32) which adjoin the insulating region below the lower cell regions (20) and an opposite-conductivity buried web (44) which laterally surrounds each buried region is employed to improve programming efficiency. Connective regions (46) extend from the buried web to the upper semiconductor surface to contact electrical leads (54) typically arranged in a parallel pattern. The maximum dopant concentration in the intermediate cell regions occurs vertically within 20% of their mid-points.

Abstract: A semiconductor PROM contains a group of PROM cells (12) each consisting of a pair of opposing diodes oriented vertically with their common intermediate region (22 and 24) fully adjoining a recessed oxide insulating region (16). The PN junction (30) of the upper diode of each pair lies in non-monocrystalline semiconductor material. A composite buried layer consisting of buried regions (32) which adjoin the insulating region below the lower cell regions (20) and a buried web (44) which laterally surrounds each buried region is employed to improve programming efficiency as well as provide intermediate electrical connections.

Abstract: A semiconductor PROM containing a group of PROM cells (12) each consisting of a pair of opposing diodes oriented vertically with their common intermediate region (22) fully adjoining a recessed oxide insulating region (16) is fabricated by a process in which the insulating region serves as a mask to control the lateral extents of the dopants utilized to define the diodes. The intermediate cell regions are ion implanted to obtain maximum dopant concentration near their mid-points. This facilitates programming operation.

Abstract: A system for providing a plurality of synchronous timing signals having period values that are not even multiples of the clock period including a plurality of local edge generators receiving the clock signals, each local generator including local programmable means to count clock signals and provide local outputs upon receiving predetermined clock signals and local programmable delay means for providing a timing signal after a delay interval following each local output, the resolution of the local delay means being greater than that of the clock.