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Introduction
Each starts the friend who from 286 times contacts PC certainly to be able to realize profoundly progresses the convenience which to the computer technology leap brings for ours life and the work, these technology advancement mainly manifests in the CPU basic frequency is getting higher and higher, the storage capacity is getting bigger and bigger, as well as between the chip and the chip, the module and the module, the system and the system interlock main line’s data transfer rate to be also getting quicker and quicker. Figure 1 described a typical computer motherboard, above revolves the bus type possibly includes the ethernet, USB, PCIExpress, SAS, HDMI, SATA, FBDIMM and UWB and so on. These bus structure’s common ground is:①Is the serial data link, the transmission and the receive uses two pair of difference holding wire transmission, did not have the independent clock line, the data format to contain the clock;②The data transfer rate is high, can achieve Gb/s even above the 10Gb/s speed rank, thus the serial data is also in the design must the key consideration question;③On the identical main line’s many connection component (or module) has the possibility very much by the different factory manufacture, different circuitry, different PCB, different fabrication technology, but actually must move in the same main line construction, therefore how to guarantee that the different factory component’s operation uniformity is the challenge which electronic engineer must face.
Figure 1 on computer motherboard’s typical main line standard
Without the custom, not Cheng Fangyuan. Each industrial standard organization for the promotion profession development, has formulated the corresponding test specification, requests to carry on the authentication the product to complete assigns the item parameter the test survey. For example, the IEEE802.3 subcommittee formulated specially
the 10BaseT/100BaseT/1000BaseT three speed rank ethernet electrical interface’s test criteria, has defined several dozens survey parameter qualified scope, including eye chart template, vibration, rising time, difference output electricity equality. If designs main line product after special equipment survey, all parameters meet the code requirement, then thought that the product design is qualified, and can be mutually compatible with other factories, this process is called “the uniform test”. Also for instance the USBIF organization has also formulated the complete standard in view of the USB2.0 connection’s uniform test, the USB2.0 product which the designer designs after the test, must meet the code requirement completely, is allowed to get USB2.0 to symbolize, can by other customer approval.
The high speed serial data link’s uniform test is a complex topic, both the request test facility factory can provide the high performance the instrument, and requests to test engineer to be able to solve the problem fully using the instrument. Everybody hoped that the instrument is we solves a question part, but is not a question’s part. The American Strength Branch Company proposed in the digital oscilloscope and in the serial data analyzer platform “automated test” the concept, provides the complete solution for many serial data standard uniformity test, including the newest digital oscilloscope and the serial data analyzer, can support the highest 18GHz simulation band width, 60GS/s the real-time sampling rate. As a solution’s part, the strength branch has also promoted automated uniformity test software package QualiPHY, devotes in the enhancement working efficiency, reduces engineer to operate the instrument and the production report order of complexity, will let engineer not think that again the uniform test will be the dull duty. As follows to everybody introduced how QualiPHY is helps engineer to deal with the challenge which the high speed serial data link testing faces.
Figure 2 100Base-T overswing test oscilloscope establishment request
Uniform test difficulty
At present, carries on the serial data link uniformity test the main instrument platform is the high speed figure oscilloscope or the serial data analyzer (for example strength branch company’s SDA), engineer when uses these equipment carry on the test, generally faces the following introduction the difficulty.
how does 1 grasp the test criteria content
Along with the serial bussing technique’s day-by-day progress, the signal integrity becomes the question which the designer most has a headache, including the crosstalk, EMI, the vibration, the reflection, the seal noise, the displacement and the static electricity and so on, these questions to designs, the test to be similarly important. Each kind of serial main line’s uniformity test criteria defined adapted the high speed signal huge signal integrity analysis demand. For example, the 100BaseT uniformity test specification request survey eye chart, the vibration, the rise/fall time, the overswing/under flush, the difference power output, the height level symmetry, the dutyfactor displacement and so on; The USB2.0 uniformity test specification has also defined several dozens parameters to the HighSpeed Device analysis. Each kind of parameter’s survey has defined the establishment parameter regarding oscilloscope’s use, as shown in Figure 2 is the ethernet uniformity test to the overswing parameter survey oscilloscope establishment request.
The test specification has the applicable scope to each kind of parameter, the actual observed value must fall on this scope only then determine to qualified.
Therefore, tests engineer both to need to grasp the complete test parameter tabulation, and needs to understand each kind of parameter correspondence the oscilloscope active status, but also needs the clear each parameter the qualified measuring range. This is the very complex work.
how do 2 establish the testing environment
Serial data’s signal quality analysis and the uniform test cannot leave generally test jig’s auxiliary. Jig’s leading role is between the different signal form the interconversion, for instance the ethernet test jig is the twisted pair line signal conversion probe head signal. Each survey project needs to test the jig, to measure that the component and the oscilloscope three between establish the appropriate interconnection analysis situs relations, grasps all connection relations is also the very difficult matter accurately.
Figure 3 USB2.0 the test item has custom-made the window
3 pair of instrument operations are not very familiar
The serial data trunk technology’s rapid progress proposed to oscilloscope’s performance a higher standard, simultaneously also does cause the modern high-end oscilloscope’s operation order of complexity also day by day to enlarge, remembers in uniformity test procedure each step, how the oscilloscope should operate, is very not the easy matter.
how do 4 produce the test report
Each hardware engineers have this kind of intimate understanding, the compilation test report are take the trouble the time-consuming work. Needs to collect the measurement result, the contrast standard standard to analyze some survey parameter to be whether qualified, preserves the essential profile picture and pastes to the report, if the test parameter reaches several dozens much, for instance USB2.0 the test, that work load will be very huge.
5 serial data agreement type are quite many
The computation technology popularizes and the content demand swift and violent growth unceasingly needs the quicker digital channel, at present PCI Express, SATA, HDMI, SAS and so on serial data trunk construction already widely applied in the digital environment, moreover faster PCIExpress2.0, HDMI1.3, SATAIII and so on second generation also already started with the third generation main line construction to appear or is researching and developing in the process, in addition more universal Ethernet and USB2.0, the serial main line agreement’s type is getting more and more rich, to tests engineer’s request to be also getting higher and higher. The different agreement test’s cut means that makes a fresh start to study.
QualiPHY software characteristic
The difficult problem which when carries on serial main line uniformity test faces in view of high speed figure system engineer, the American Strength Branch Company promotes QualiPHY which function formidable, easy to use the software package, below from several aspects introduced how this software does help engineer to solve these uniform test difficult problem.
Figure 4 SATA I 1.5Gb/s uniform automation test procedure hint
1 user may have custom-made the survey project
The complete uniform test contains ten several even several dozens projects, but is not each time tests must traversal the complete project.
The QualiPHY software support user may have custom-made the test item, may choose single or the many projects tests separately, thus enhanced the flexibility greatly. Figure 3 what description is USB2.0 High Speed Device or the Hub test item has custom-made the window.
2 automated tests
According to chooses the good test item, QualiPHY launches a series of automation test procedure immediately: Automatic setup oscilloscope operational parameter including sampling rate, memory depth, acquisition time, ordinate axis scale division, triggering level and so on; Automatic definition survey parameter; Automatic transfer third party software like Matlab to the profile operation, the automated analysis profile and the measurement result, outputs the analysis result automatically, the entire test procedure is completely the automation, does not need any manual intervention. Meets the synchronized demonstration test condition and the process prompt in the test procedure.
QualiPHY the software operates the oscilloscope in view of engineer to carry on the uniform test the handling characteristics to optimize the automated test flow, raised the uniform test efficiency effectively, and reduced the operation instrument difficulty and the redundant labor greatly, causes the test procedure feature fun, but no longer is the dull duty, as soon as thus promotes is the depth engineer’s affection. Figure 4 is the SATA uniformity test automation contact surface.
3 graph prompts
QualiPHY software’s user interface design very user-friendly and direct-viewing practical, it will demonstrate by the graph way the uniform test in each link will test jig, oscilloscope main engine and the DUT three between analysis situs relations, the user does not need to remember, can establish the testing environment correctly.
4 automated analysis metrical data
After oscilloscope gathering profile, and after standard survey parameter, the QualiPHY software will do automatically it with the standard the contrast, and will output this parameter through or defeat’s conclusion. Figure 5 had demonstrated the QualiPHY software package to the 10BaseT peak value difference output voltage analysis’s result, the actual observed value is the 2.52V,802.3 standard qualified scope is 2.20~2.80V, obviously this parameter testing passes.
5 integrated many kinds of serial data agreements
The QualiPHY software integrated many kinds of serial agreements, including popular SATA, UWB, PCIE, SAS, FBDIMM, HDMI, USB, ENET and so on. The different serial agreement uses the same user interface and the operating procedure, engineer does not need to be redundant studies, extrapolates then fast grasps the complete agreement the uniform test flow.
6 automatic output reports
The QualiPHY software after completing all assigns the project the survey and the analysis duty, automatically will produce artistic, practical, the meet standards standard test report, the report format may choose is XML, HTML or PDF the form. Saved the compilation test report time, engineer has been possible to place more energy in the product design, but was not in the test.
Figure 6 QualiPHY system establishment
QualiPHY system establishment
QualiPHY software package support many kinds of serial data standard agreements, may also move directly on the digital oscilloscope, may also move on other computers. The recommendation execution way is the isolated operation on a control computer, through the TCP/IP agreement and test oscilloscope establishment correspondence connection. Does the main advantage is on the oscilloscope demonstrates the profile, the QualiPHY software demonstration analysis result, two kind of contact surfaces may simultaneously by the user observation. The QualiPHY software after-crops the establishment parameter and the survey orders on the oscilloscope, the oscilloscope upload capture profile to the QualiPHY analysis, QualiPHY will analyze the result to control on PC to output artistic, practical and conforms to the standard result report. Figure 6 described the QualiPHY_for_ENET testing environment. The user may go to www.lecroy.com to download the QualiPHY software package freely, realized by oneself it gives the high speed serial data uniformity test to bring highly effective and the convenience.
Conclusion
QualiPHY the automated uniformity testing software movement on the high-end digital oscilloscope or the serial data analyzer, in view of the model high speed serial data link uniformity test’s flow characteristic, has provided comprehensive and the rich software function and the man-machine contact surface, reduced engineer to operate instrument’s order of complexity effectively, raised the test efficiency, thus caused the uniformity to test into a very interesting work, but non-dull duty.
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