100Base-TX Test Procedure for the 82544 Chip
1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
148
Intel Confidential
I.5
Specification 9.1.8 - Duty Cycle Distortion (DCD)
I.5.1
Test Case
Duty Cycle Distortion (specification 9.1.8)
I.5.2
Test Purpose
To measure the Duty Cycle at the four MLT-3 transitions, using a pattern in non-scrambled mode.
I.5.3
Specification
When measured between 50% voltage points on +Vout and –Vout, all positive pulse widths,
negative pulse widths, and mid-level time periods must be between 15.50 nsec and 16.50 nsec.
Note:
The specification wording within the ANSI TP-PMD can be confusing, but the illustration in the
TP-PMD clearly shows that +/- 0.5 nsec variation is allowed.
I.5.4
Test Equipment
•
Digitizing oscilloscope with at least 1 GHz bandwidth
•
P6247 Differential Probe (or equivalent differential probe)
•
Host computer with gigconf.exe software
I.5.5
Test Fixtures
100 ohm termination fixture 9.1.2.A.