Analysis of electro-optic waveforms

A laser probing system for laser probing a device under test having a cell, comprising:

• a laser source;
• an optical system adapted to provide an optic probe at selectable locations of the device under test in response to light from said laser source, receive reflected light from the device under test, and output said reflected light;
• a receiver circuit that receives said reflected light from said optical system, and provides a laser probe (LP) waveform in response to said reflected light;
• a combinational logic analysis (CLA) processor that simulates an optical response to a test pattern at a target location of the cell of the device under test and forms a CLA waveform in response;
• and
• a test controller having a first input for receiving said CLA waveform, a second input for receiving said LP waveform, and an output for providing a control signal, wherein said test controller applies said test pattern to the device under test, triggers said receiver circuit to capture said LP waveform, and causes a target net waveform to be extracted from the LP waveform by:
• (i) simulating a CLA cross-talk waveform to model cross-talk from selected non-target nets by simulating an optical response of the cell to said test pattern at the target location with the target net masked;
• (ii) estimating a cross-talk weight;
• and (iii) determining the 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.

An analysis system for a laser probing system, comprising:

• a receiver circuit having an input for receiving reflected light produced from an optic probe, a control input for receiving a control signal, and an output for providing a laser probe (LP) waveform of said reflected light in response to an activation of said control signal;
• and
• a combinational logic analysis (CLA) processor having an output for providing a CLA waveform in response to simulating an optical response to a test pattern at a target location on a surface of a cell of a device under test;
• and
• a test controller having a first input for receiving said CLA waveform, a second input for receiving said LP waveform, a first output for providing said control signal, a second output for providing said test pattern, wherein said test controller applies said test pattern to the device under test, triggers said receiver circuit to capture said LP waveform, and causes a target net waveform to be extracted from the LP waveform by:
• (i) simulating a CLA cross-talk waveform to model cross-talk from selected non-target nets by simulating an optical response of the cell to said test pattern at the target location with the target net masked;
• (ii) estimating a cross-talk weight;
• and (iii) determining the 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.