100Base-TX Test Procedure for the 82544 Chip
1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
144
Intel Confidential
Figure I-8. Upper-right MLT-3 mid-level, upper cursor
15. AVERAGE the values of the cursors from the last two steps (average four cursor values). The
result is the mid-level value that will be considered the base of the pulse. [-21.75 mV is the
average mid-level, from example
through
16. Scroll horizontally through the waveform, until the approximate center of the pulse peak is
visible on the oscilloscope display. Select the horizontal cursors. Move one cursor to the top of
the ripple on the peak voltage. Move the second cursor to the bottom of the ripple on the peak
voltage. The average of these two cursor levels is the pulse top voltage that is used to calculate
the 10% and 90% points on the rising and falling edges. [See
and
.]
Figure I-9. Positive Pulse Peak, lower cursor
