SerialXpress® – Advanced Jitter Generation for AWG

Features & Benefits

• Flexibility: Jitter generation has become so flexible that the user now has the freedom to try various permutations and combinations of jitter parameters like Pj, Rj, ISI, Noise, Delay, etc.
• Replicate scenarios: The signals are digitally synthesized. All AWG setups can be recalled and the scenarios can be replicated on any other AWG within seconds.
• Analog nature of digital signals: In reality all digital signals are analog in nature and hence SerialXpress exploits the capabilities of an AWG to generate real-world signals.
• Ease of use: It is easy to integrate a multitude of Sj tones into the waveforms at no additional cost. Band-limited Rj can be injected with ease.
• Crest Factor Emulation (CFE): Users can now apply any amount of peak pseudo-random jitter needed to their bit patterns which can reduce test times. Test cases can be repeated accurately enabling fast receiver debug cycles. SerialXpress can also create worst-case scenarios to stress receivers by accurately controlling the Crest Factor of the random jitter.
• Programmable pre/de-emphasis and preshoot: Most of the next-generation standards like PCIe, 10GbE, SAS, or USB 3.0 need more than one tap for pre/de-emphasis signal generation. The SerialXpress Advanced Pre/De-emphasis feature offers the ultimate in flexibility, giving users the ability to program the pre/de-emphasis and preshoot sample by sample.
• Channel emulation through cascaded S-parameter filter: Touchstone files can easily be inserted to simulate the exact behavior of cable emulators, which can be again controlled and modified by adding jitter and other parameters. You can also tweak the imported touchstone file data to adjust the ISI and see how the receiver responds to those variations. The effect of the channel can also be de-embedded by selecting the Inverse filtering option. Closed EYE can be opened up by adding the right amount of pre-emphasis or by varying the rise time. You can also cascade up to 6 touchstone files to emulate a cascaded channel that might include connectors, fixtures, and channel models.
• ISI Direct Dial-in: ISI can be directly dialed-in at ease. It’s no longer necessary to use FR4 traces which are inflexible and need frequent calibration when switching from one to another.
• Presets: SerialXpress supports any emerging standard data rate from 500 Kb/s to 8 Gb/s when teamed with the appropriate Tektronix AWG. There are ready-to-use presets that allow you a head-start on your testing.
• Offline mode: SerialXpress applications can run on an external PC, thereby reducing the time taken to synthesize large waveforms and leaving the AWG free for continued testing.

Applications

• Design, debug, characterization, and compliance testing of high-speed serial data receivers
• SATA, PCIe, SAS, DisplayPort, Fibre Channel, HDMI, USB, MIPI, Receiver Testing

Jitter Generation Made Easy

SerialXpress is a powerful easy-to-use software package to synthesize high-speed serial data signals for Arbitrary Waveform Generators (AWG). It runs as an integral part of the AWG5000/7000 Series arbitrary waveform generators or from an external PC.

SerialXpress enables creation of exact waveforms required for thorough and repeatable design validation, margin/characterization, and conformance testing of high-speed serial data receivers. It considerably simplifies the signal creation and jitter simulations, thus reducing overall development and test time.

SerialXpress, in addition to supporting generation of jitter (Random, Periodic (Sinusoidal), Inter Symbol Interference (ISI), and Duty Cycle Distortion (DCD)), also supports Spread Spectrum Clocking (SSC), pre-emphasis, and noise addition. This allows the user to create a combination of various impairments simultaneously to stress the receiver. SerialXpress also allows the waveforms to be captured from Tektronix oscilloscopes and to be replayed using arbitrary waveform generators.

A programmatic interface enables easy integration of SerialXpress into test automation systems.

Scrambling, PWM, 4-PAM, and 8b/10b Encoding

The input data pattern can be scrambled by defining a polynomial. The user could enable the 8b/10b encoding option if the input pattern is in 8-bit word format before applying other impairments like jitter, SSC, and ISI. Users can also define the pattern duty cycle using the Pulse Width Modulation (PWM) feature, which allows for alternatively encoding the bit stream to 4-PAM.

Jitter Addition

Up to 4 different sinusoidal jitters with different amplitudes, frequencies, and phases can be added to the base pattern. Three independent band-limited random jitters can also be added to the base pattern.

SSC Modulation

SSC can be added with precisely controlled profile, spread, deviation, modulation, and df/dt. It supports Triangular, Sinusoidal, and Custom SSC profiles, where the custom SSC profile allows you to import your own user-defined profile by literally allowing any kind of shape to be added as SSC to the base pattern. You can also define the exact location and duration of df/dt on the SSC slope.

Advanced Pre/De-emphasis and Noise

Many standards such as PCIe require the output waveform to be pre/de-emphasized. SerialXpress allows easy addition of pre/de-emphasis, including preshoot, with all other jitter parameters. Vertical noise can also be added at both near and far end of the channel.

ISI Creation

SerialXpress allows creation of ISI in two ways. First, the ISI value can be directly dialed-in. Second, an S-parameter file generated from a Tektronix sampling oscilloscope or a vector network analyzer can be directly convolved with the base pattern to recreate the channel characteristics. By applying inverse filtering the effects of the channel can be de-embedded from the system. Also, ISI within the S-parameter can be scaled upwards or downwards, which will alter the characteristics of the channel.

Delay

SerialXpress allows users to introduce delay to the waveform, and this feature can also generate skew between channels or patterns.

Base Pattern

SerialXpress is bundled with several sample patterns for various standards like SATA, Display Port, SAS, PCIe, HDMI, USB, MIPI, and Fibre Channel. Patterns can also be directly entered in a Binary, Symbol, or Hex editor or loaded as a file.

Idle State*¹

Standards like SATA call for OOB signaling which requires idle state followed by a burst. Now the user can directly create this idle state without the need of using additional power dividers. Noise and offset can also be added to these idle state waveforms. Idle state can also be defined as a part of pattern definition.

Calibration

SerialXpress has a built-in calibration routine which controls a Tektronix oscilloscope and calibrates the output of the AWG for periodic jitter and random jitter, reducing the need for time-consuming manual calibration.

Bandwidth Expansion Filter

Rise time of the AWG can be expanded further by applying the bandwidth expansion filter. For example, when used with AWG7122C and Option 06, this compensates for the DAC roll-off at higher frequencies and extends the bandwidth up to 9 GHz.

*¹ When idle state (z) is included in the pattern definition, no jitter is applied.

Marker Outputs

Marker outputs can be configured to be the same as the input base pattern or to generate clocks at a user-defined frequency including subdata rates.

Batch Processing

When more than one pattern needs to be synthesized, you can use batch processing that enables creation of multiple waveforms with a combination of random jitter and sinusoidal jitter with a maximum of 4 different frequencies.

Overview Window

All the jitter parameters can be switched ON/OFF from the Overview window.