## Statistical Analysis Results

### Results to View

These are the results data from the Statistical Analysis phase of the analysis. There is a table of data as well as waveform data to view.

ResultDescription
BERShows the statistical eye, data bathtub, and clock PDF.
Statistical EyeShows the statistical eye.
BathtubShows the data bathtub curve, the clock PDF, intersection of the two (Net BER), or all three.
Vertical BathtubShows the vertical (voltage) bathtub curve at the average clock time (0.5UI) or at a user defined (UI).
DJShows the deterministic jitter probability density function.
ContoursShows the eye contours. The node names identify the inner and outer eye contours. The contours are shown for the target BER values.
CrosstalkShows the statistical eye of the crosstalk and noise at the receiver. For more information, see Model Jitter and Noise While Designing Serial Link or Model Jitter and Noise While Designing Parallel Link.
Impulse ResponseThe impulse response of the analog channel, equalized channel, or both.
Step ResponseThe step response of the analog channel, equalized channel, or both.
Pulse ResponseThe pulse response of the analog channel, equalized channel, or both.
Aligned Pulse Response

Shows the pulse response shifted in X and Y. The shifts are made as follows:

• Y Shift$-{Y}_{0}$, where Y0 is the Y value of the first point of the equalized pulse response.

• X Shift:$-\left(D+\frac{UI}{2000}\right)$, where D is the statistical path delay in ns and UI is in ps.

Transfer FunctionTransfer function of the analog channel, equalized channel, or both.
Probed Statistical EyeStatistical eye at the probed location(s) of the pre-layout schematic. In case of a parallel link project, the result represents the statistical eye at the receiver B node.
Probed ContoursEye contours at the probed location(s) of the pre-layout schematic. In case of a parallel link project, the result represents the eye contours at the receiver B node.
Probed CrosstalkCrosstalk eye at the probed location(s) of the pre-layout schematic. In case of parallel link project, it is the crosstalk eye at the receiver B node.
Probed Impulse ResponseImpulse response at the probed location(s) of the pre-layout schematic. In case of parallel link project, it is the impulse response at the receiver B node.
Probed Step ResponseStep response at the probed location(s) of the pre-layout schematic. In case of parallel link project, it is the step response at the receiver B node.
Probed Pulse ResponsePulse response at the probed location(s) of the pre-layout schematic. In case of parallel link project, it is the pulse response at the receiver B node.
Probed Transfer FunctionTransfer function at the probed location(s) of the pre-layout schematic. In case of parallel link project, it is the transfer function at the receiver B node.

Note

The Stat mode in the Parallel Link Designer app does not support user-defined probes but does add a single probe at the Receiver B-Node.

### Node Locations

The full node names in statistical analysis contain the designator names. For example, VTX1 is the V node for the designator TX1.

### Table Column Definitions

ParameterDefinition
Transfer NetName of the transfer net for the simulation.
TransferBus transaction (designator from-to) for the simulation.
UI (ps)Unit interval for the transmitted data, defined as the time duration for a single transmitted symbol.
Symbol Rate (Gbps)Rate at which symbols are transmitted on the channel. The delivered payload UI can be lower for an encoding such as 8b10b is used, or higher for a modulation such as PAM4 is used.
Stat BERAverage bit error as predicted through statistical analysis.
Stat BER FloorMinimum bit error rate at any point on the bathtub curve derived from statistical analysis.
Stat RJ (ps)Standard deviation of Gaussian distributed clock to data offset as measured at the receiver decision point. Calculated as the RMS sum of the AMI parameters `Rx_Clock_Recovery_Rj`, `Rx_Clock_Recovery_Dj`, `Rx_Clock_Recovery_Sj`, and `Rx_Clock_Recovery_DCD`. If none of these AMI parameters are present, this value defaults to 0 ps.
Stat Timing OffsetMean of the clock to data offset as measured at the receiver decision point. An offset of zero indicates that the data is being sampled exactly at the center of the data eye. This parameter can also be called the static timing offset.
Stat Path Delay

The path delay of a data pulse, as detected by clock recovery during statistical analysis.

Note

If the algorithmic models use different delay values in statistical and time domain modes, then this parameter does not have the same value as the path delay determined during time domain simulation.

Stat Eye HeightHeight of the target bit error rate contour at the average clock time. For more information, see Eye Measurement and Reporting.
Stat Eye MarginVoltage measured from the sensitivity threshold to the target BER contour at the average clock time. For more information, see Eye Measurement and Reporting.
Stat Eye Outer HeightMaximum voltage measured on the outer eye. This parameter represents the maximum voltage measured on the zero outer contour. For more information, see Eye Measurement and Reporting.
Stat Eye WidthTotal width of the target bit error rate contour at the ideal decision threshold. For more information, see Eye Measurement and Reporting.
Stat Setup TimeTime between the sensitivity threshold crossing at the early edge of the target bit error rate contour and the average clock time.
Stat Hold TimeTime between the average clock time and the sensitivity threshold crossing of the late edge of the target bit error rate contour.
Stat DJ Peak (UI)Maximum deviation from the median zero crossing time for all zero crossings in the statistical eye.
Stat DJ Sigma (UI)Standard deviation of all zero crossing times in the statistical eye.
Eq Signal/Xtalk (dB)

Ratio of equalized signal energy to the combined equalized energy of all of the crosstalk aggressors, as measured at the input to the receiver decision circuit.

An equalized signal to crosstalk ratio of 23 dB should be safe for a target BER of 10-12, and a ratio of 27 dB should be safe in general. Any signal to crosstalk ratio less than 23 dB should be investigated in detail, and will most likely not meet performance requirements.

Total Xtalk (Vrms)RMS amplitude for the combination of all of the crosstalk aggressors.
Stat Unequalized NrgUnequalized energy representing the amount of energy in the equalized impulse response that is not equalized out.
Tx Level (V)Maximum absolute value of the differential output voltage of the driver, measured when driving a load whose impedance is equal to the output impedance of the driver.
Amplitude Noise (Vrms)Standard deviation of the Gaussian distributed amplitude noise as measured at the receiver decision point.
SimulationThe name of the simulation file for the simulation.
CORNERThe process corner for the simulation. For more information, see Specify Corner Conditions in Serial Link Design or Specify Corner Conditions in Parallel Link Design.
Bit_Sequence_SetThe bit sequence set used in the analysis.
Network CharacterizationSimulation type for network characterization.
Time DomainSimulation type for time domain analysis.
COLUMNSpecific group name and value number used in the simulation. This is valid when there are variation groups in the solution space.