Note:
1.Data mask to insure mini-LVDS data can be latched by mini-LVDS clock correctly.
2.Real data waveform can not touch mask at each SD.
Judgment example
Pass:
1.No data waveform touch mask
2.Clear eye opening
3.Have enough margin
Fail:
1.Hold time violation
2.High Risk with data NG
Measurement tips:
1.Display pattern should be complex data transition pattern.
2.Measure with persistence mode over 3k trigger samples.
3.Differential probes should be de-skew and calibration to make sure correct measurement.
4.Measure point should be closed to each SD----wire < 1 inch, as short as possible
1.By different SD, the signal quality and timing will be different.
2.To insure each SD can normal operation, measure with each SD is necessary.
Example
Special case: ΔVID
For eye opening is enough but waveform reflection is serious
1.VID means the difference of common level and the first rising peak or falling peak in the condition of differential probe test.
2.ΔVID is just for simulation guarantee. This is not for the test guarantee.
評論