EE240: Advanced Analog Integrated Circuits
TuTh 9:30-11am, 540A/B Cory
To run the eye diagram test, you will first need to run the "eye_check.pl" script to generate an "eye_chk.vec" file that you can use to generate the digital data into the transmitter, as well as to check whether the outputs of your comparator are correctly reproducing the transmitted data. When you first copy eye_check.pl into your directory, you will need to run the following command:
chmod u+x eye_check.pl
Also, make sure that you place the "eye_patt.txt" file in the same directory as eye_check.pl.
The eye_check.pl scripts takes four command-line inputs: the symbol time in ns (e.g., 0.5 for 2 GS/s - i.e., 4 Gb/s), the supply voltage of your transmitter in volts, the delay in ns (e.g., 6) between when the digital bits are fed to the transmitter and when they should be checked at the output of the comparator, and the common mode voltage at the output of your comparator (e.g. 1). This last parameter tells the script what voltage it should use to decide if the output of the comparator is a 1 or a 0.
If your comparator is not receiving the correct bits, you should see a listing inside of the <spice_deck_name>.err file. If you later decide to change the symbol-rate of your link, you will need to re-run eye_check.pl.