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LTC2000 Skew Measurement - Trigger Source


We want to check the LVDS timing in our application of the LTC2000 DAC. I think I understood the Datasheet corrctly and got, that we have to add up the skew which is measured out of the phase of each pair. We want to measure the skew with an high speed oscilloscope. We attach a differential Probe on TSTN and TSTP. That is ok. But what should we use as a trigger source? I mean if we use the TSTP/N signals as source, the would align I guess. The Datasheet is a bit unclear at this point. I was using now the DCKI_P signal as a trigger.

Would that procedure be right:

Channel 1: DCKI

Channel 2: TSTN/TSTP

Trigger on DCKI.

Apply patterns on DAC 0xAAAA and 0x5555

Now set LMX_ADR = 0xF and LMX_MSEL=0 to measure DCKIP/N (on TSTP/N) ---> STORE WAVEFORM

Then set LMX_ADR = 0xF and LMX_MSEL=1 to measure DA0P/N (on TSTP/N)

Difference between rising edges of stored waveform (DCKIP/N) and current measured (DA0P/N) is the skew of the rising edge.

Same for falling edge.

Can this procedure be correct?