Abstract: A method a low cost and production-integrable technique for providing a signal diagram. The data signal is edge-detected and asynchronously sampled (or alternatively a clock signal is latched). The data signal or a second signal is compared to a settable threshold voltage and sampled. The edge and comparison data are folded according to a swept timebase to find a minimum jitter period. The crossing of the signal diagram edges is determined from a peak of a histogram of the folded edge data. A histogram of ratios of the sample values versus displacement from the position of the crossing location is generated for each threshold voltage. The technique is repeated over a range of settable threshold voltages. Then, the ratio counts are differentiated across the histograms with respect to threshold voltage, from which a signal diagram is populated.
Type:
Grant
Filed:
June 30, 2006
Date of Patent:
June 3, 2008
Assignee:
International Business Machines Corporation
Inventors:
Hayden C. Cranford, Jr., Fadi H. Gebara, Jeremy D. Schaub
Abstract: A method and system and calibration technique for power measurement and management over multiple time frames provides responsive power control while meeting global system power consumption and power dissipation limits. Power output of one or more system power supplies is measured and processed to produce power values over multiple differing time frames. The measurements from the differing time frames are used to determine whether or not system power consumption should be adjusted and then one or more devices is power-managed in response to the determination. The determination may compare a set of maximum and/or minimum thresholds to each of the measurements from the differing time frames. A calibration technique uses a precision reference resistor and voltage reference controlled current source to introduce a voltage drop from the input side of a power supply sense resistor calibration is made at the common mode voltage of the power supply output.
Type:
Grant
Filed:
January 11, 2005
Date of Patent:
April 1, 2008
Assignee:
International Business Machines Corporation
Inventors:
Dhruv Manmohandas Desai, Nickolas J. Gruendler, Carl A. Morrell, Gary R. Shippy, Michael Leo Scollard, Michael Joseph Steinmetz, Malcolm Scott Ware, Christopher L. Wood
Abstract: A method and system for defect evaluation using IDDQ voltage linearity provides improved IDDQ testing for determining whether manufacturing defects in a VLSI device are likely to cause functional faults. IDDQ data is collected at multiple power plane voltages (VDDs) for a test vector at which a fault is activated. The IDDQ vs. VDD is then examined and a range of VDDs over which the characteristic IDDQs are non-linear with respect to VDD is determined. Peaks in the first derivative of the IDDQ vs. VDD curve indicate a particular VDD at which the onset of non-linearity in the IDDQ occurs. The VDD point below which the curve is non-linear indicates the relative resistance of a fault with respect to the driving point resistance of the node at which the fault is located. The relative resistance is directly determinative of additional circuit delay cause by the fault and/or whether the fault will cause a logic level transmission failure.
Type:
Grant
Filed:
December 3, 2003
Date of Patent:
October 24, 2006
Assignee:
International Business Machines Corporation
Inventors:
Anne Elizabeth Gattiker, Phillip J. Nigh
Abstract: A system of beam narrowing for resolution enhancement produces a narrowed beam for use in surface imaging. The system of beam narrowing for resolution enhancement uses a Fabry-Perot cavity to sharpen the intensity profile of a light source imaged through the system. The optical distance between reflective surfaces forming the Fabry-Perot cavity is tuned to select one of the surfaces as a target surface. The beam width is thereby optimized to a minimum width at the selected target surface. Multiple Fabry-Perot cavities can be cascaded by interposing one or more additional partly reflective surfaces between a first surface and a second underlying surface. The optical distances between all of the surfaces are tuned to select a target surface. The beam width is optimized at the selected target surface to produce a beam narrower than the beam produced by a single Fabry-Perot cavity.