Teledyne LeCroy QPHY-MOST150 - Manual (Page 19)

QPHY-MOST150o Software Option
920456 Rev B
19
Eye Diagram Testing 1.2, 2.4, 4.1, 4.3
This test is performed at points SP1, SP2 and SP4 and creates an eye diagram from the input signal
and tests it against the appropriate mask using the specified clock edge. The measurements at test
point SP2 use a normalized mask (i.e. relative to the B0/B1 measured levels) while those at the
remaining test points use an absolute mask. The result reported is the number of mask hits.
Note: In cases where a large number of mask hits are detected the number of UI displayed will be
reduced to keep the processing time manageable.
Figure 10 - Oscilloscope Configuration after Eye Diagram Tests
Shown on this screen:
• Eye diagram created from the differential input signal after the clock is recovered from the signal
using the FC Golden PLL with Cutoff Divisor of 2359 and a PLL Cutoff of 125 KHz.
Figure 11 - Eye Diagram Results
In the measurement section:
• P1 is the number of times the eye diagram made contact with the SP1 mask.
• P2 is the number of times the eye diagram did not make contact with the SP1 mask.