02-03-2015 06:13 AM
We are currently working on implementing the eye scan feature with a Kintex 7 (xc7k325tffg900-2).
I have seen that the vertical offset parameter (ES_VERT_OFFSET) can range from -127 to 127 (8-bit binary in LPM mode).
Can someone give me the value in voltage of this parameter (differential voltage threshold)? What is the maximum voltage value? Is it function of the amplitude of our input signal or is it fixed?
Thank you very much for your answer,
02-11-2015 03:30 AM
08-11-2015 01:23 PM
I'm wondering if there is any more discussion on this topic.
From looking through the DC and AC switching characteristics for the Kintex7 (DS183) you can see that the differential peak-to-peak voltage is 1.25V for speeds 6.6Gb/s and up (it's 2V peak to peak below 6.6Gb). If the peak to peak voltage is 1.25, would it make sense that the 256 steps (codes) of threshold would apply to the entire range? Meaning, each step would be about 4mV (or even greater in the 2V peak to peak case).
I'm trying to work this out myself, so please let me know if this isn't the case.