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Agilent Technologies DSOX4USBSQ USB 2.0, Electrical Testing Notes

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14

DSOX4USBSQ USB 2.0 Signal Quality Analysis Application Electrical Testing Notes

1

Preparing for Signal Quality Analysis

 

Single-Ended Probe Connection for Full/Low Speed Signal Quality Tests

Low and Full Speed host tests require two single- ended probes.

Low and Full Speed device tests require three single- ended probes — the 
third probe is for the adjacent D- /D+ signal.

The passive probes that are included with the oscilloscope are sufficient.

Summary of Contents for DSOX4USBSQ USB 2.0

Page 1: ...s1 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes ...

Page 2: ...the terms of such license Restricted Rights Legend If software is for use in the performance of a U S Government prime contract or sub contract Software is delivered and licensed as Commercial computer soft ware as defined in DFAR 252 227 7014 June 1995 or as a commercial item as defined in FAR 2 101 a or as Restricted computer software as defined in FAR 52 227 19 June 1987 or any equivalent agenc...

Page 3: ...tests against the hub Runs all the signal quality tests for the selected speed and device type combination Automatically sets up the oscilloscope for the selected tests Provides detailed results information for each test that has been run Lets you save the detailed results information to an HTML report In This Book This manual contains notes on the electrical tests that are performed by the DSOX4U...

Page 4: ...4 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes ...

Page 5: ...itional Equipment and Set Up for Signal Quality Compliance Testing 16 High Speed Electrical Test Bed Computer 16 Additional Set Up for Signal Quality Compliance Testing 17 2 Device Signal Quality Testing Device Hi Speed Signal Quality Test 20 Device Hi Speed Connection Differential Probe 24 Device Hi Speed Connection SMA Cables 25 Device Hi Speed Compliance Test Packets 26 Device Full Speed Signal...

Page 6: ...eam Full Speed Signal Quality Test 60 Hub Upstream Full Speed Connection 62 Hub Upstream Full Speed Compliance Test Packets 63 5 Hub Downstream Signal Quality Testing Hub Downstream Hi Speed Signal Quality Test 66 Hub Downstream Hi Speed Connection Differential Probe 69 Hub Downstream Hi Speed Connection SMA Cables 70 Hub Downstream Hi Speed Compliance Test Packets 71 Hub Downstream Full Speed Sig...

Page 7: ...sis Oscilloscope Requirements 8 Fixtures for Signal Quality Tests 9 Probe Requirements 12 Miscellaneous Cables and Devices 15 This chapter describes the equipment and software required for performing signal quality analysis with the 4000 X Series oscilloscope and the DSOX4USBSQ USB 2 0 Signal Quality Analysis application ...

Page 8: ...oscilloscope works fine For Full and Low Speed Tests Full and Low Speed tests can be performed with 200 MHz 350 MHz 500 MHz 1 GHz or 1 5 GHz bandwidth model oscilloscopes Full Speed testing is best on a 4 channel oscilloscope because when using a 2 channel oscilloscope channels 1 and 2 are non interleaved and the sample rate will be below the 4 GSa s that the USB IF testing procedures require If F...

Page 9: ...ure is used for Full and Low Speed tests See Fixture for Full Low Speed Signal Quality Tests on page 10 Fixtures for Hi Speed Signal Quality Tests Hi Speed testing requires one of these test fixtures Device Hi Speed Signal Quality Test Fixture part number E2649 66401 This fixture can be ordered using the Agilent part number E2649 60001 which includes two RF SMA m vertical 50 ohm termination connec...

Page 10: ...res Older versions of the Hi Speed signal quality test fixtures exist and may be used Device Hi Speed Signal Quality Test Fixture part number E2645 66507 Host Hi Speed Signal Quality Test Fixture part number E2645 66508 When using these older fixtures with the 1131A 1133A or 1134A InfiniiMax differential probes you also need the Agilent header adapter part number 01131 68703 This header adapter is...

Page 11: ...Preparing for Signal Quality Analysis 1 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 11 This fixture can be ordered using the model number E2646A B ...

Page 12: ...up the Agilent 113xA differential probe for connection to the Hi Speed signal quality test fixture Attach the socketed probe head to the differential probe amplifier Handle the socketed probe head and header adapter carefully For durability epoxy can be used to strengthen the assembly Only apply epoxy to back noncomponent side of probe head NOTE The N2750A Series InfiniiMode probes cannot be used ...

Page 13: ...A connectors for probing with SMA cables Figure 1 Differential Probe Setup NOTE In certain test situations there may not be a ground connection between the oscilloscope and the device under test DUT This may lead to the signal seen by the differential probe to be modulated up and down due to the mid frequency switching power supply Connecting the oscilloscope ground to the DUT ground will be requi...

Page 14: ...is Single Ended Probe Connection for Full Low Speed Signal Quality Tests Low and Full Speed host tests require two single ended probes Low and Full Speed device tests require three single ended probes the third probe is for the adjacent D D signal The passive probes that are included with the oscilloscope are sufficient ...

Page 15: ... Speed 5 m USB cable any listed on USB IF web site 1 1 1 as needed 1 5 m USB cable any listed on USB IF web site 1 1 n a n a 1 m USB cable any listed on USB IF web site n a n a n a as needed Modular AC power cord 2 2 2 n a Hi Speed USB Hub any listed on USB IF web site 1 n a n a n a Hi Speed USB Device any listed on USB IF web site 1 n a n a n a USB self powered hub and power supply These are the ...

Page 16: ...Toolkit Setup Instruction document which comes with the High Speed Electrical Test Tool Kit Software on page 16 High Speed Electrical Test Tool Kit Software You can download the High Speed Electrical Test Tool Kit software USBHSET from the developers tools page at the USB Implementers Forum web site http www usb org developers tools The High Speed Electrical Test Tool Kit software contains and use...

Page 17: ...rical Test Tool software the driver stack will automatically switch to the Microsoft EHCI driver stack Additional Set Up for Signal Quality Compliance Testing When performing USB 2 0 signal quality compliance testing instead of testing the signal quality of real world packets be sure to take these additional set up steps 1 Turn on the oscilloscope to allow 30 minutes of warm up time prior to use 2...

Page 18: ...18 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 1 Preparing for Signal Quality Analysis ...

Page 19: ...SB 2 0 Signal Quality Analysis Application Electrical Testing Notes 2 Device Signal Quality Testing Device Hi Speed Signal Quality Test 20 Device Full Speed Signal Quality Test 28 Device Low Speed Signal Quality Test 33 ...

Page 20: ...peed Signal Quality test fixture place the TEST switch S1 in the ON position Verify the yellow TEST LED is lit 4 On the oscilloscope s front panel press the Analyze key 5 In the Analyze Menu press the Features softkey then select USB Signal Quality 6 Press the Test softkey and select the Device Hi Speed Signal Quality test Table 3 Equipment Used in Device Hi Speed Signal Quality Tests Quantity Ite...

Page 21: ...nals This provides the maximum sample rate Channels 1 and 2 are one pair and channels 3 and 4 are the other pair Hi Speed tests using single ended SMA cable connections are not supported on 2 channel oscilloscopes because the sample rate does not meet the required 5 GSa s c Press the Test Type softkey and select Near end or Far end The terms near end and far end are based on which end of the cable...

Page 22: ...lity test When tests are run the oscilloscope stops acquisitions if they are running analyzes the data on screen and then displays the results When the test completes the results are automatically displayed You can press the Display Results softkey to disable or reenable the test results display NOTE Tests can take several minutes to run and cannot be cancelled once started ...

Page 23: ...Device Signal Quality Testing 2 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 23 ...

Page 24: ...ata See Also Chapter 6 Saving Test Results to an HTML File starting on page 81 Device Hi Speed Connection Differential Probe Perform these connection steps 1 Attach the 5V power supply to J5 of the E2649 66401 Device Hi Speed signal quality test fixture Leave the TEST switch at the OFF position Verify the green POWER LED is lit and the yellow TEST LED is not lit 2 Connect the TEST PORT of the Devi...

Page 25: ...Leave the TEST switch at the OFF position Verify the green POWER LED is lit and the yellow TEST LED is not lit 2 Connect the TEST PORT of the Device Hi speed Signal Quality test fixture into the upstream facing port of the device under test using the 4 USB cable 3 Connect the INIT PORT of the test fixture to a Hi speed capable port of the Test Bed Computer using the 5 meter USB cable 4 Apply power...

Page 26: ...he HS Electrical Test Tool software on the Hi Speed Electrical Test Bed computer 2 Select Device and click the TEST button to open the Device Test dialog box 3 In the Device Test dialog box the device under test should be enumerated with the device s VID shown together with the root port in which it is connected 1 2 3 4 Hi Speed Host 5m Cable Device Under Test 4 Init Port Test Port 5V D D TP2 Devi...

Page 27: ... DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 27 4 Select TEST_PACKET from the Device Command drop down menu and click EXECUTE This forces the device under test to continuously transmit test packets ...

Page 28: ... analog input source channel connected to the D signal channel 2 in the previous connection instructions b Press the D Source softkey and select the analog input source channel connected to the D signal channel 3 in the previous connection instructions On 4 channel oscilloscopes you are forced to use different channel pairs for the D and D signals This provides the maximum sample rate Channels 1 a...

Page 29: ... oscilloscope for the selected test For optimal test results you can make adjustments to the auto setup Generally you want one packet of data plus the time of one bit on each end across the oscilloscope s display Also vertical scale and offset should be adjusted so that the signals take six vertical divisions without being clipped You should see the transmitted test packet on the oscilloscope as b...

Page 30: ...hannel 1 inputs 2 Attach the SQiDD board to two USB ports at the end of 5 self powered hubs and a host system Hub 1 has to be a hi speed hub and hub 2 has to be a full speed hub The rest of the hubs can be either hi speed or full speed hubs 3 Attach a full speed device under test to the same section of the SQiDD board If the section has a switch it should be set to ON 4 Attach another full speed d...

Page 31: ...Test Tool software on the Hi Speed Electrical Test Bed computer 2 Select Device and click the TEST button to open the Device Test dialog box 1 2 3 4 Full Speed Device Under Test Probe D and D in Device Under Test Path Host Self powered Hub 1 Self powered Hub 2 Self powered Hub 3 Self powered Hub 4 Self powered Hub 5 5m Cable 5m Cable 5m Cable 5m Cable 5m Cable SQiDD Adjacent Full Speed Device 5m C...

Page 32: ...roller should appear in the device enumeration list If you do not know which VID PID belongs to the device under test detach the device under test and enumerate the bus once Then reattach the device under test and enumerate again this time paying attention to the new device attached 4 Highlight the device under test and select LOOP DEVICE DESCRIPTOR from the Device Command drop down menu 5 Click E...

Page 33: ...l Quality test 6 Press the Signals softkey In the USB Signal Quality Signals Menu a Press the D Source softkey and select the analog input source channel connected to the D signal channel 2 in the previous connection instructions b Press the D Source softkey and select the analog input source channel connected to the D signal channel 3 in the previous connection instructions Table 5 Equipment Used...

Page 34: ...to automatically set up the oscilloscope for the selected test For optimal test results you can make adjustments to the auto setup Generally you want one packet of data plus the time of one bit on each end across the oscilloscope s display Also vertical scale and offset should be adjusted so that the signals take six vertical divisions without being clipped You should see the transmitted test pack...

Page 35: ...assive probes to the oscilloscope s Channel 2 Channel 3 and Channel 1 inputs 2 Attach the SQiDD board to two USB ports at the end of 5 self powered hubs and a host system Hub 1 has to be a hi speed hub and hub 2 has to be a full speed hub The rest of the hubs can be either hi speed or full speed hubs 3 Attach a low speed device under test to the same section of the SQiDD board If the section has a...

Page 36: ...Test Tool software on the Hi Speed Electrical Test Bed computer 2 Select Device and click the TEST button to open the Device Test dialog box 1 2 3 4 Hi Speed Hub Full Speed Hub Low Speed Device Under Test Probe D and D in Device Under Test Path Host Self powered Hub 1 Self powered Hub 2 Self powered Hub 3 Self powered Hub 4 Self powered Hub 5 5m Cable 5m Cable 5m Cable 5m Cable 5m Cable SQiDD Adja...

Page 37: ...roller should appear in the device enumeration list If you do not know which VID PID belongs to the device under test detach the device under test and enumerate the bus once Then reattach the device under test and enumerate again this time paying attention to the new device attached 4 Highlight the device under test and select LOOP DEVICE DESCRIPTOR from the Device Command drop down menu 5 Click E...

Page 38: ...38 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 2 Device Signal Quality Testing ...

Page 39: ...SQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 3 Host Signal Quality Testing Host Hi Speed Signal Quality Test 40 Host Full Speed Signal Quality Test 46 Host Low Speed Signal Quality Test 50 ...

Page 40: ...ality 5 Press the Test softkey and select the Host Hi Speed Signal Quality test 6 Press the Signals softkey In the USB Signal Quality Signals Menu a Press the Test Connection softkey and select whether you are using a Single ended with SMA cables or Differential probe connection b If you are using a differential connection press the Source softkey and select the analog input source channel connect...

Page 41: ...t supported on 2 channel oscilloscopes because the sample rate does not meet the required 5 GSa s c Press the Test Type softkey and select Near end or Far end The terms near end and far end are based on which end of the cable the test fixture is attached in relation to the device being tested The point where measurements are made dictates what eye template is used 7 Press the Auto Setup softkey to...

Page 42: ...an press the Display Results softkey to disable or reenable the test results display The analyzed acquisition remains on screen and can be viewed by moving or dismissing the results dialog box You can run tests when the oscilloscope is already stopped This is useful in the case of embedded hosts and other cases where the device under test DUT may not easily be placed in a test mode and you want to...

Page 43: ...ach the Agilent 113xA differential probe to TP2 of the test fixture Ensure the polarity on the probe lines up with D which is the pin nearest the USB connector 3 Please terminate the fixture s SMA connectors with 50 Ohm terminators 4 Connect the TEST PORT of the E2649 66402 Host Hi Speed Signal Quality test fixture into the port under test of the host controller using the 4 USB cable The host cont...

Page 44: ... PORT of the E2649 66402 Host Hi Speed Signal Quality test fixture into the port under test of the host controller using the 4 USB cable The host controller here refers to the Hi speed Electrical Test Bed Computer that has the HS Electrical Test Tool on it Host Hi Speed Compliance Test Packets To set up the Host computer to transmit compliance test packets perform these steps 1 Invoke the HS Elect...

Page 45: ...nalysis Application Electrical Testing Notes 45 3 In the Host Test dialog box select TEST_PACKET from the Port Control drop down menu 4 Enter the port number of the port under test 5 Click EXECUTE This forces the port under test to continuously transmit test packets ...

Page 46: ...d select the analog input source channel connected to the D signal channel 2 in the previous connection instructions b Press the D Source softkey and select the analog input source channel connected to the D signal channel 3 in the previous connection instructions On 4 channel oscilloscopes you are forced to use different channel pairs for the D and D signals This provides the maximum sample rate ...

Page 47: ... one bit on each end across the oscilloscope s display Also vertical scale and offset should be adjusted so that the signals take six vertical divisions without being clipped You should see the transmitted test packet on the oscilloscope as below 8 Press the Run Test softkey to run the selected signal quality test When tests are run the oscilloscope stops acquisitions if they are running analyzes ...

Page 48: ...teps 1 Attach the passive probes to the oscilloscope s Channel 3 and Channel 2 inputs 2 Attach the SQiDD board to the root hub on the host under test 3 Attach 5 self powered hubs and a full speed device to the same section of the SQiDD board If the section has a switch it should be set to ON Hub 1 has to be a full speed hub and hub 2 a Hi speed hub The other hubs can be either full speed or hi spe...

Page 49: ...Testing Notes 49 1 2 3 4 Root Hub Full Speed Test Device SQiDD Host Under Test Probe D and D in Host Under Test Path Self powered Hub 1 Self powered Hub 2 Self powered Hub 3 Self powered Hub 4 Self powered Hub 5 5m Cable 5m Cable 5m Cable 5m Cable 5m Cable 5m Cable D D Hi Speed Hub Full Speed Hub ...

Page 50: ...ress the D Source softkey and select the analog input source channel connected to the D signal channel 2 in the previous connection instructions b Press the D Source softkey and select the analog input source channel connected to the D signal channel 3 in the previous connection instructions On 4 channel oscilloscopes you are forced to use different channel pairs for the D and D signals This provi...

Page 51: ...signal quality test When tests are run the oscilloscope stops acquisitions if they are running analyzes the data on screen and then displays the results When the test completes the results are automatically displayed You can press the Display Results softkey to disable or reenable the test results display The analyzed acquisition remains on screen and can be viewed by moving or dismissing the resu...

Page 52: ... Channel 2 inputs 3 Attach the SQiDD board to the root hub on the host under test 4 Attach a low speed device to the same section of the SQiDD board If the section has a switch it should be set to ON 5 Connect the oscilloscope Channel 2 probe to D probe point on the SQiDD board Connect the oscilloscope Channel 3 probe to the D probe point on the SQiDD board 6 Exit the HS Electrical Test Tool if yo...

Page 53: ...SOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 4 Hub Upstream Signal Quality Testing Hub Upstream Hi Speed Signal Quality Test 54 Hub Upstream Full Speed Signal Quality Test 60 ...

Page 54: ...vice Hi Speed Signal Quality test fixture place the TEST switch S1 in the ON position Verify the yellow TEST LED is lit 4 On the oscilloscope s front panel press the Analyze key 5 In the Analyze Menu press the Features softkey then select USB Signal Quality 6 Press the Test softkey and select the Device Hi Speed Signal Quality test Table 9 Equipment Used in Hub Hi Speed Signal Quality Test Upstrea...

Page 55: ...signals This provides the maximum sample rate Channels 1 and 2 are one pair and channels 3 and 4 are the other pair Hi Speed tests using single ended SMA cable connections are not supported on 2 channel oscilloscopes because the sample rate does not meet the required 5 GSa s c Press the Test Type softkey and select Near end or Far end The terms near end and far end are based on which end of the ca...

Page 56: ...ou can press the Display Results softkey to disable or reenable the test results display The analyzed acquisition remains on screen and can be viewed by moving or dismissing the results dialog box You can run tests when the oscilloscope is already stopped This is useful in the case of embedded hosts and other cases where the device under test DUT may not easily be placed in a test mode and you wan...

Page 57: ...Connect the TEST PORT of the test fixture into the upstream facing port of the hub under test using the 4 USB cable 3 Connect the INIT PORT of the test fixture to a hi speed port of the Test Bed Computer Apply power to the hub 4 Attach the Agilent 113xA differential probe to D D of TP2 on the test fixture Ensure the polarity on the probe lines up with D on the fixture 5 Please terminate the fixtur...

Page 58: ...w TEST LED is not lit 2 Connect the TEST PORT of the Device Hi speed Signal Quality test fixture into the upstream facing port of the device under test using the 4 USB cable 3 Connect the INIT PORT of the test fixture to a Hi speed capable port of the Test Bed Computer using the 5 meter USB cable 4 Apply power to the device 5 Attach the SMA cables to the SMA connectors D and D of TP2 on the test f...

Page 59: ...smit compliance test packets perform these steps 1 Invoke the HS Electrical Test Tool software on the Hi Speed Electrical Test Bed computer Select Hub and click the TEST button to enter the Hub Test dialog box 2 In the Hub Test dialog box the hub under test should be enumerated with the hub s VID shown together with the USB address Select TEST_PACKET from the Hub Command drop down menu 3 Click EXE...

Page 60: ... and select the analog input source channel connected to the D signal channel 2 in the previous connection instructions b Press the D Source softkey and select the analog input source channel connected to the D signal channel 3 in the previous connection instructions On 4 channel oscilloscopes you are forced to use different channel pairs for the D and D signals This provides the maximum sample ra...

Page 61: ...selected test For optimal test results you can make adjustments to the auto setup Generally you want one packet of data plus the time of one bit on each end across the oscilloscope s display Also vertical scale and offset should be adjusted so that the signals take six vertical divisions without being clipped You should see the transmitted test packet on the oscilloscope as below 8 Press the Run T...

Page 62: ...hannel 3 and Channel 1 inputs 2 Attach the SQiDD board to two USB ports at the end of 5 self powered hubs and a host system Hub 1 has to be a hi speed hub and hub 2 has to be a full speed hub The rest of the hubs can be either hi speed or full speed hubs 3 Attach a full speed hub under test to the same section of the SQiDD board If the section has a switch it should be set to ON 4 Attach another f...

Page 63: ...rical Test Tool software on the Hi Speed Electrical Test Bed computer 2 Select Device and click the TEST button to open the Device Test dialog box 1 2 3 4 Hub Under Test upstream port Probe D and D in Device Under Test Path Host Self powered Hub 1 Self powered Hub 2 Self powered Hub 3 Self powered Hub 4 Self powered Hub 5 5m Cable 5m Cable 5m Cable 5m Cable 5m Cable SQiDD Adjacent Full Speed Devic...

Page 64: ...controller should appear in the device enumeration list If you do not know which VID PID belongs to the device under test detach the device under test and enumerate the bus once Then reattach the device under test and enumerate again this time paying attention to the new device attached 4 Highlight the hub under test and select LOOP DEVICE DESCRIPTOR from the Device Command drop down menu 5 Click ...

Page 65: ...ality Analysis Application Electrical Testing Notes 5 Hub Downstream Signal Quality Testing Hub Downstream Hi Speed Signal Quality Test 66 Hub Downstream Full Speed Signal Quality Test 72 Hub Downstream Low Speed Signal Quality Test 76 ...

Page 66: ...lect USB Signal Quality 5 Press the Test softkey and select the Host Hi Speed Signal Quality test 6 Press the Signals softkey In the USB Signal Quality Signals Menu a Press the Test Connection softkey and select whether you are using a Single ended with SMA cables or Differential probe connection b If you are using a differential connection press the Source softkey and select the analog input sour...

Page 67: ...re not supported on 2 channel oscilloscopes because the sample rate does not meet the required 5 GSa s c Press the Test Type softkey and select Near end or Far end The terms near end and far end are based on which end of the cable the test fixture is attached in relation to the device being tested The point where measurements are made dictates what eye template is used 7 Press the Auto Setup softk...

Page 68: ...You can press the Display Results softkey to disable or reenable the test results display The analyzed acquisition remains on screen and can be viewed by moving or dismissing the results dialog box You can run tests when the oscilloscope is already stopped This is useful in the case of embedded hosts and other cases where the device under test DUT may not easily be placed in a test mode and you wa...

Page 69: ...gilent 113xA differential probe to TP2 of the test fixture Ensure the polarity on the probe lines up with D on the fixture located nearest to the USB connector 3 Connect the upstream port of the hub to a high speed root port of the test bed computer 4 Connect the TEST PORT of the test fixture into the down stream facing port under the test of the hub Apply power to the hub 5 Please terminate the f...

Page 70: ...e ON position Verify green POWER LED and yellow TEST LED are both lit 2 Connect the upstream port of the hub to a high speed root port of the test bed computer 3 Connect the TEST PORT of the test fixture into the down stream facing port under the test of the hub Apply power to the hub 4 Attach the SMA cables to the SMA connectors D and D of TP2 on the test fixture 1 2 3 4 Hi Speed Host Hub upstrea...

Page 71: ...teps 1 Invoke the HS Electrical Test Tool software on the Hi Speed Electrical Test Bed computer Select Hub and click the TEST button to enter the Hub Test dialog box 2 In the Hub Test dialog box click the Enumerate Bus button once The hub under test should be enumerated with the hub s VID shown together with the USB address 3 Select TEST_PACKET from the Port Control drop down menu 4 Enter the port...

Page 72: ...ress the D Source softkey and select the analog input source channel connected to the D signal channel 2 in the previous connection instructions b Press the D Source softkey and select the analog input source channel connected to the D signal channel 3 in the previous connection instructions On 4 channel oscilloscopes you are forced to use different channel pairs for the D and D signals This provi...

Page 73: ...me of one bit on each end across the oscilloscope s display Also vertical scale and offset should be adjusted so that the signals take six vertical divisions without being clipped You should see the transmitted test packet on the oscilloscope as below 8 Press the Run Test softkey to run the selected signal quality test When tests are run the oscilloscope stops acquisitions if they are running anal...

Page 74: ... probes to the oscilloscope s Channel 3 and Channel 2 inputs 2 Attach the SQiDD board to the hub under test 3 Attach the upstream port of the hub under test to the end of 4 self powered hubs and a host system Hub 1 has to be a full speed hub and hub 2 a Hi speed hub The other hubs can be either full speed or hi speed hubs 4 Attach a full speed device to the same section of the SQiDD board If the s...

Page 75: ...ation Electrical Testing Notes 75 1 2 3 4 Full Speed Test Device SQiDD Probe D and D in Host Under Test Path Host Self powered Hub 1 Self powered Hub 2 Self powered Hub 3 Self powered Hub 4 Hub Under Test 5m Cable 5m Cable 5m Cable 5m Cable 5m Cable 5m Cable D D Full Speed Hub Hi Speed Hub ...

Page 76: ...al Quality Signals Menu a Press the D Source softkey and select the analog input source channel connected to the D signal channel 2 in the previous connection instructions b Press the D Source softkey and select the analog input source channel connected to the D signal channel 3 in the previous connection instructions On 4 channel oscilloscopes you are forced to use different channel pairs for the...

Page 77: ...take six vertical divisions without being clipped You should see the transmitted test packet on the oscilloscope as below 8 Press the Run Test softkey to run the selected signal quality test When tests are run the oscilloscope stops acquisitions if they are running analyzes the data on screen and then displays the results When the test completes the results are automatically displayed You can pres...

Page 78: ...board to the hub under test 4 Attach the upstream port of the hub under test to the end of 4 self powered hubs and a host system Hub 1 has to be a full speed hub The other hubs can be either full speed or hi speed hubs 5 Attach a low speed device to the same section of the SQiDD board If the section has a switch it should be set to ON 6 Connect the oscilloscope Channel 2 probe to D probe point of ...

Page 79: ...is Application Electrical Testing Notes 79 1 2 3 4 SQiDD Host Probe D and D in Host Under Test Path Low Speed Test Device Mouse Self powered Hub 1 Self powered Hub 2 Self powered Hub 3 Self powered Hub 4 Hub Under Test 5m Cable 5m Cable 5m Cable 5m Cable 5m Cable D D Full Speed Hub ...

Page 80: ...80 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 5 Hub Downstream Signal Quality Testing ...

Page 81: ...n the oscilloscope s front panel press Save Recall Save Format and select the USB Signal Quality option 3 Press the second softkey then use the File Explorer to browse to the location where you want to save the test results file 4 Press the File Name softkey and specify the name of the test results file 5 Press the Press to Save softkey NOTE You can also e mail test results by pressing Save Recall...

Page 82: ...82 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes 6 Saving Test Results to an HTML File ...

Page 83: ...through If you need a feed through that will let you probe Hi Speed signals with the N2750A Series InfiniiMode probe you can use the E2646A B SQiDD test fixture normally used for Full and Low Speed testing and InfiniiMode probes Use the center section of the board as the feed though Probe the signals using the test points Figure 2 E2646A B SQiDD Board ...

Page 84: ...84 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes A Probing Hi Speed Signals with InfiniiMode Using SQiDD as a Feedthrough ...

Page 85: ...eed signal quality test 33 device signal quality testing 19 devices USB 15 differential probe connection 12 DSOX4USBFL USB 2 0 Full Low Speed triggering and decode 8 DSOX4USBH USB 2 0 Hi Speed triggering and decode 8 DSOX4USBSQ USB 2 0 Signal Quality Analysis application 8 E E2646A B SQiDD board 10 E2646A B SQiDD test fixture 83 EHCI driver stack 16 electrical test bed computer 16 equipment requir...

Page 86: ...86 DSOX4USBSQ USB 2 0 Signal Quality Analysis Application Electrical Testing Notes Index USB electrical test fixtures 9 USBHSET software 16 ...

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