100Base-TX Test Procedure for the 82544 Chip
1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
140
Intel Confidential
Figure I-4. Negative Peak Differential Output Voltage
I.4
Specification
9.1.6 - Rise/Fall Times
I.4.1
Test Purpose
To measure the rise and fall times of a 100Base-TX transmit waveform. Both positive and negative
waveforms need to be measured.
I.4.2
Specification
Rise time is the time it takes for the differential output signal to rise from the MLT-3 mid-level (~0
volts) to Vout or to –Vout. Fall time is the time it takes for a signal to fall from Vout
or –Vout back to the MLT-3 mid-level (~0 volts).
Rise and fall times for the positive differential output will be the time difference (delta nsec.)
between 10% of +Vout and 90% of +Vout.
Rise and fall times for the negative differential output will be the time difference (delta nsec.)
between 10% of -Vout and 90% of -Vout.
Note:
Note that measured rise and fall times must be within the range between 3.0 nsec. and 5.0 nsec. The
maximum variation in any rise time with respect to any fall time shall be 0.5 nsec or less.
I.4.3
Test Equipment
•
Digitizing Oscilloscope with at least 1 GHz bandwidth
•
Differential Probe with 1 GHz or greater bandwidth (like P6247)
•
Host computer with gigconf.exe software (for 82554 silicon).