The FS5000 Jitterlyzer performs

physical layer In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer; The layer most closely associated with the physical connection between devices. This layer may be implemented by a PHY chip. Th ...

serial bus In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are ...

jitter In electronics and telecommunications, jitter is the deviation from true periodicity of a presumably periodic signal, often in relation to a reference clock signal. In clock recovery applications it is called timing jitter. Jitter is a significa ...

evaluation. It can inject controlled jitter and measure the characteristics of incoming jitter. When teamed with a

logic analyzer A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, asse ...

protocol analyzer A protocol analyzer is a tool (hardware or software) used to capture and analyze signals and data traffic over a communication channel. Such a channel varies from a local computer bus to a satellite link, that provides a means of communication usi ...

, it can correlate these measurements with protocol analysis. Physical-layer tests can be performed while the system under test is processing live bus traffic."FuturePlus Systems and DFT Microsystems collaborate on next generation High Speed Serial IO Jitter Tools". Internet Business Systems, Inc. 2007. edacafe.com

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Jitter measurements

The FS5000 measures jitter in two categories:

Timing

''There are four different timing measurements'': *Bathtub Plot - The

bathtub curve The bathtub curve is widely used in reliability engineering and deterioration modeling. It describes a particular form of the hazard function which comprises three parts: *The first part is a decreasing failure rate, known as early failures. *Th ...

can provide tremendous insight into the

BER ''Ziziphus mauritiana'', also known as Indian jujube, Indian plum, Chinese date, Chinese apple, ber, and dunks is a tropical fruit tree species belonging to the family Rhamnaceae. It is often confused with the closely related Chinese jujube (' ...

performance of a link under test. A bathtub curve is obtained by drawing a horizontal line across the waveform under test. The probability distribution function for signal transitions (zero crossings) from a high voltage to a low voltage or a low voltage to a high voltage is then computed. The bathtub curve is useful because it can provide a lot of insight into the behavior of a system. Apart from estimating

, it also provides an indication for the amount of margin that is in the system. When coupled with protocol testing with the Jitterlyzer, a high margin enables engineers to quickly rule out the physical layer as a potential cause of certain protocol errors. * Statistics - The Jitterlyzer’s measurement routines uncover total jitter and BER directly (without requiring mathematical extrapolation). This routine for random jitter (RJ) and

deterministic jitter In electronics and telecommunications, jitter is the deviation from true periodicity of a presumably periodic signal, often in relation to a reference clock signal. In clock recovery applications it is called timing jitter. Jitter is a signi ...

(DJ) separation is included for completeness. Also a number is provided for RJ and DJ on real-life traffic. * Bus View - Shows channel to channel skew of four channels simultaneously. *Jitter Histogram - This routine is performed on real-life traffic. It selects the zero-crossing voltage in the incoming data. It then counts the number of transitions of the high-speed serial signal as a function of phase positions. A histogram of number of hits versus delay is then plotted.

Eye

''There are three different eye measurements'' *

Eye diagram In telecommunication, an eye pattern, also known as an eye diagram, is an oscilloscope display in which a digital signal from a receiver is repetitively sampled and applied to the vertical input, while the data rate is used to trigger the horiz ...

- This routine is performed on real-life traffic. It provides much more information than just a vertical eye opening or a horizontal eye opening. Instead, it provides a first indication of parameters such as dispersion in the signal path, rise-time issues, etc. Click on the link and you will see an example of an eye diagram that is obtained using the Jitterlyzer. As can be seen, an indication of noise throughout the whole eye is made, as opposed to, for example, only at the center. * Oscilloscope - This measurement allows the user to see an oscilloscope trace in persistent mode, allowing direct inspection of the eye. Color represents the frequency with which the measured trace passes through each point, with red representing the most frequent, and black representing the least. Note that frequency is normalized to a maximum value of 1. *

Voltage Histogram Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to m ...

- This measurement is similar to the jitter histogram except that it is done in the vertical domain. It shows the amount of voltage noise that exists on the high-speed serial signal and is similar in principle to the vertical eye height."Features - FS5000 JitterlyzerTM". FuturePlus Systems Corporation. 2006. FuturePlus.com

Jitter generation

Data pattern

*LIVE traffic *Preprogrammed Compliance patterns

Jitter profile

*Frequency range 19.07 kHz - 19.99 MHz *Amplitude range 40ps - 1200ps

Differential swing

*400-1600mv

External links

Jitter analysis
tool from

FuturePlus Systems Future plc is an international multimedia company established in the United Kingdom in 1985. The company has over 220 brands that span magazines, newsletters, websites, and events in fields such as video games, technology, films, music, photogr ...

References

{{reflist Digital electronics Electronic test equipment