100BASE-TX Waveform Overshoot
1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
36
Intel Confidential
9.3
Test Equipment
•
Oscilloscope with at least 1 GHz bandwidth
•
Differential probe with at least 1 GHz bandwidth and capacitance less than or equal to 1 pF
•
Host computer running gigconf.exe
9.4
Test Fixtures
100
Ω
UTP test load (
)
9.5
Test Procedure
1. Connect the test equipment and UUT as shown below.
Figure 9-2. Test Setup 1
2. From the 100 BASE-TX PHY Configuration Tests menu in gigconf.exe, select the Amplitude
Symmetry: 9.1.2.2 test.
3. Configure the oscilloscope according to
.
Differential Probe
w/ 1 GHz BW
Unit Under Test
(UUT)
Digitizing
Oscilloscope
Test Fixture 40-25
100 Ohm Resistive Load
RX
RJ-45
TX
Table 9-1. Setting for Positive Waveform Overshoot
Scope Parameter
Setting
Horizontal Scale
~25 ns/division
Vertical Range
-150 mV to +1050 mV (1200 mV over the full vertical scale)
Trigger Type
Positive pulse width triggering:
116 ns lower bound, 128 ns upper bound
Trigger Level
500 mV
Record Length
Large enough to enable viewing of one complete MLT-3 (3-level)
waveform by scrolling horizontally
Display Type
Average