Teledyne LeCroy Eye Doctor II User Manual
Page 24
Eye Doctor II Software
Equalizer Settings
The Equalizer feature allows you to see the waveform after equalization. Since Decision
Feedback Equalization requires a clock in order to work,
is available from the Eye Doctor
II Equalizer dialog.
The Eye Doctor II Equalizer dialog contains several user interface elements in addition to buttons for con-
figuring CTLE, FFE, Clock Recovery and DFE. (When using SDAIII-CompleteLinQ, these items appear in dif-
ferent places, as described.)
The Train FFE & DFE button automatically trains the FFE and the DFE (if enabled) and finds the bit rate
for clock recovery. The automatic training of the FFE and/or DFE can be disabled with the respective
dialog boxes. When using EyeDoctor II equalization capabilities from within SDAIII-CompleteLinQ, use the
Train buttons that are contained within the FFE and DFE configurations screens.
The Nominal Bit Rate shown in this dialog sets the bitrate used for Emphasis, FFE and DFE. When using
SDA II or SDAIII-CompleteLinQ, this value is inherited from the Nominal Rate configured in the Signal
dialog.
The Data Path to DFE In selection box allows the user to decide if the data path to the DFE should come
directly from the serial data signal input, or should first pass through the CTLE, or should first pass
through the CTLE and FFE (as shown in the following images). This provides the ability to perform CTLE
and/or FFE equalization on the signal prior to the DFE equalization. Additionally, this allows the CTLE
and/or FFE equalization to be performed on the signal used for clock recovery and only DFE used on the
actual data signal. (When using SDAIII-CompleteLinQ, this selector is configured in the Linear EQ dialog.)
CTLE equalizer applied to data only, CTLE and FFE applied to clock recovery.
CTLE and FFE equalizers applied to both data and clock recovery.
There are two output waveforms from the Equalizer section of Eye Doctor II. These are EyeDrOut and
EyeDrClk. The signals represent the equalized data signal and the recovered clock signal. These outputs
22
922961 Rev A