Advanced Micro Devices Corporation

Gopinath Ranganathan

Venkat Krishnan Ravikumar

Nathan Linarto

Shei Lay Phoa

Wen Tsann Lua

Jiann Min Chin

Abel Tan Yew Hong

Jiann Minn Chin

Yi Xuan Seah

An optic probe is used to measure signals from a device under test. The optic probe is positioned at a target probe location within a cell of the device under test, the cell including a target net to be measured and a plurality of non-target nets. A test pattern is applied to the cell with the optic probe a laser probe (LP) waveform is obtained in response. A target net waveform is extracted from the LP waveform by: (i) simulating a combinational logic analysis (CLA) cross-talk waveform to model cross-talk from selected non-target nets by simulating an optical response of the cell to the test pattern with the target net masked; (ii) estimating a cross-talk weight; and (iii) determining a target net waveform by weighting the CLA cross-talk waveform according to the cross-talk weight and subtracting the weighted CLA cross-talk waveform from the LP waveform.

Analysis of electro-optic waveforms

A control system for placing an optic probe includes a receiver circuit that receives reflected light produced from the optic probe and provides a laser probe (LP) waveform of the reflected light in response to an activation of a trigger signal. A combinational logic analysis (CLA) processor provides a CLA waveform in response to simulating an optical response at a target location on a surface of a cell of a device under test to a test pattern. A test controller receives the CLA waveform and the LP waveform, and has a first output for providing the trigger signal, a second output for providing the test pattern, and a third output for providing a position signal. The test controller updates the position signal to move the optic probe closer to the target location according to a degree of fit between the LP waveform and the CLA waveform.

Probe placement for laser probing system

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Singapore, Singapore

Gopinath Ranganathan