gigabit ethernet ee 164 group 2 – presentation 7 ungtae lee april 8th 2004
TRANSCRIPT
Gigabit Ethernet
EE 164 Group 2 – Presentation 7
Ungtae Lee April 8th 2004
Gigabit Ethernet Project Status 3/22-4/7
Completed/ In Progress Built the Tx/Rx Troubleshoot the Tx/Rx Built the aggressive design
Tx Optically test aggressive Tx
Upcoming Tasks Build and test aggressive
design Rx Evaluate crosstalk
between Tx/Rx Possible second design? Alignment tolerance
testing for unconn. VCSEL
Group 2 – Presentation 7 April 8th 2004
Gigabit Ethernet Normal Design Rx/Tx
Group 2 – Presentation 7 April 8th 2004
Heated up due to short
Heated up due to short
Gigabit Ethernet Normal Design Rx/Tx
Group 2 – Presentation 7 April 8th 2004
To fix problem, used Etcher to separate the ground plane with the power supply.
-Unfortunately, it did not solve the problem of shortage. Receiver still heated up.
Gigabit Ethernet Normal Design Rx
Group 2 – Presentation 7 April 8th 2004
-Electrical and optical testing showed the Transmitter to be nonfunctional.-Compared test board with our Rx.-Found pins 15 and 7 were not grounded in the test board-Etched out and removed pins from the Maxim 3264 chip
-Made no difference in test results-Decided to move on to aggressive design
Gigabit Ethernet Aggressive Design Tx
Group 2 – Presentation 7 April 8th 2004
-Initial Electrical test proved to be successful. -Used the probe to detect an eye in the differential output of the Tx
Electrically Probed one of the differential outputOutput from probe shows eye (using
PRBS7 input, connected dots)
Gigabit Ethernet Aggressive Design Tx
Group 2 – Presentation 7 April 8th 2004
-Did not have the correct adapter-Manually held up the output of the VSCEL to the input of the Optical Spectrum Analyzer
Gigabit Ethernet Aggressive Design Tx
Group 2 – Presentation 7 April 8th 2004
849 nm optical signal was detected
-Surprisingly, the Optical Spectrum Analyzer detected an optical signal at approximately 849nm-Verification that the VSCEL was working
Gigabit Ethernet Aggressive Design Tx
Group 2 – Presentation 7 April 8th 2004
-Initial optical testing of the transmitter shows a rough eye-only one PRBS 7 input
Gigabit Ethernet Aggressive Design Tx
Group 2 – Presentation 7 April 8th 2004
-Overview of the Tx optical testing-Noted that using both differential inputs produced better results-example of how optical attenuators were added together using connectors
Gigabit Ethernet Aggressive Design Tx
Group 2 – Presentation 7 April 8th 2004
PRBS7 input with 2 sec persistence
0 dB attenuation 2 dB attenuation
3 dB attenuation 4 dB attenuation
Gigabit Ethernet Aggressive Design Tx
Group 2 – Presentation 7 April 8th 2004
PRBS7 input with 2 sec persistence
5 dB attenuation 6 dB attenuation
7 dB attenuation
Any questions?