FIBRE CHANNEL CONSORTIUM

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1 FIBRE CHANNEL CONSORTIUM FC-PI-2 Clause 9 Electrical Physical Layer Test Suite Version 0.21 Technical Document Last Updated: August 15, 2006 Fibre Channel Consortium Durham, NH Phone: University of New Hampshire Fax: University of New Hampshire

2 TABLE OF CONTENTS MODIFICATION RECORD...3 ACKNOWLEDGMENTS...4 INTRODUCTION...5 GROUP 1: Transmitter Verification...7 Test TX Bit Rate...8 Test Differential Output Voltage...9 Test Rise and Fall Times...10 Test Transmitter Eye Masks...11 Test TX Jitter...12 Test TX RMS Common Mode Voltage (4G Only)...13 Test TX Skew (1&2G Only)...14 GROUP 2: β T 4-Gigabit Return Loss Verification...15 Test Transmitter Differential Mode Return Loss...16 Test Transmitter Common Mode Return Loss...17 Test Receiver Differential Mode Return Loss...18 Test Receiver Common Mode Return Loss...19 GROUP 3: Impedance Verification...20 APPENDICES...21 Appendix 9.A - Hardware Requirements, Test Fixtures, and Setups...22 UNH IOL Fibre Channel Consortium 2 Clause 9 4G Electrical Physical Layer Test Suite v0.21

3 MODIFICATION RECORD June 30, 2005 (Version 0.1) DRAFT RELEASE, INTENDED FOR INTERNAL REVIEW ONLY Matthew Plante: Initial Draft. November 30, 2005 (Version 0.2) DRAFT RELEASE, INTENDED FOR INTERNAL REVIEW ONLY Matthew Plante: Updated to include all devices speeds in the transmitter tests. August 15, 2005 (Version 0.21) DRAFT RELEASE, INTENDED FOR INTERNAL REVIEW ONLY Michael Davidson: Removed references to Research Computing Center. UNH IOL Fibre Channel Consortium 3 Clause 9 4G Electrical Physical Layer Test Suite v0.21

4 ACKNOWLEDGMENTS The University of New Hampshire would like to acknowledge the efforts of the following individuals in the development of this test suite. Andy Baldman Matthew Plante UNH UNH UNH IOL Fibre Channel Consortium 4 Clause 9 4G Electrical Physical Layer Test Suite v0.21

5 INTRODUCTION The University of New Hampshire s (IOL) is an institution designed to improve the interoperability of standards based products by providing an environment where a product can be tested against other implementations of a standard. This particular suite of tests has been developed to help implementers evaluate the electrical Physical Layer functionality of their Fibre Channel products. These tests are designed to determine if a Fibre Channel product conforms to specifications defined in Clause 9 of the FC-PI-2 Rev 10.0 Fibre Channel Standard (hereafter referred to as FC-PI-2 ). Successful completion of all tests contained in this suite does not guarantee that the tested device will successfully operate with other Fibre Channel products. However, when combined with satisfactory operation in the IOL s interoperability test bed, these tests provide a reasonable level of confidence that the Device Under Test (DUT) will function properly in many Fibre Channel environments. The tests contained in this document are organized in order to simplify the identification of information related to a test, and to facilitate in the actual testing process. Tests are separated into groups, primarily in order to reduce setup time in the lab environment, however the different groups typically also tend to focus on specific aspects of device functionality. A three-number, dot-notated naming system is used to catalog the tests, where the first number always indicates the specific clause of the reference standard on which the test suite is based. The second and third numbers indicate the test s group number and test number within that group, respectively. This format allows for the addition of future tests in the appropriate groups without requiring the renumbering of the subsequent tests. The test definitions themselves are intended to provide a high-level description of the motivation, resources, procedures, and methodologies specific to each test. Formally, each test description contains the following sections: Purpose The purpose is a brief statement outlining what the test attempts to achieve. The test is written at the functional level. References This section specifies all reference material external to the test suite, including the specific subclauses references for the test in question, and any other references that might be helpful in understanding the test methodology and/or test results. External sources are always referenced by a bracketed number (e.g., [1]) when mentioned in the test description. Any other references in the test description that are not indicated in this manner refer to elements within the test suite document itself (e.g., Appendix 6.A, or Table ) Resource Requirements The requirements section specifies the test hardware and/or software needed to perform the test. This is generally expressed in terms of minimum requirements, however in some cases specific equipment manufacturer/model information may be provided. Last Modification This specifies the date of the last modification to this test. Discussion The discussion covers the assumptions made in the design or implementation of the test, as well as known limitations. Other items specific to the test are covered here as well. Test Setup The setup section describes the initial configuration of the test environment. Small changes in the configuration should not be included here, and are generally covered in the test procedure section (next). UNH IOL Fibre Channel Consortium 5 Clause 9 4G Electrical Physical Layer Test Suite v0.21

6 Procedure The procedure section of the test description contains the systematic instructions for carrying out the test. It provides a cookbook approach to testing, and may be interspersed with observable results. Observable Results This section lists the specific observables that can be examined by the tester in order to verify that the DUT is operating properly. When multiple values for an observable are possible, this section provides a short discussion on how to interpret them. The determination of a pass or fail outcome for a particular test is generally based on the successful (or unsuccessful) detection of a specific observable. Possible Problems This section contains a description of known issues with the test procedure, which may affect test results in certain situations. It may also refer the reader to test suite appendices and/or other external sources that may provide more detail regarding these issues. UNH IOL Fibre Channel Consortium 6 Clause 9 4G Electrical Physical Layer Test Suite v0.21

7 GROUP 1: Transmitter Verification The University of New Hampshire Overview: This group of tests verifies the transmitter s electrical specifications for one through four-gigabit Fibre Channel signals, as defined in Clause 9 of FC-PI-2. All of the tests described in this section are currently undergoing development at the University of New Hampshire. Comments and questions regarding the implementation of these tests are welcome, and may be forwarded to the Fibre Channel Consortium at the UNH (fcclab@iol.unh.edu). UNH IOL Fibre Channel Consortium 7 Clause 9 4G Electrical Physical Layer Test Suite v0.21

8 Test TX Bit Rate The University of New Hampshire Purpose: To verify that the bit rate of the DUT transmitter device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table 19. Resource Requirements: See Appendix 9.A Last Modification: November 30, 2005 Discussion: In order to ensure that a link partner s receiver can track and recover the transmitter s clock, it is important to establish a tolerance on the amount of skew that the clock can have. This is important since the recovered clock is used to make decisions about where the bit boundaries are located in the signal. Reference [2] shows the nominal signaling rates for each link speed with a rate tolerance of ± 100 ppm. 1-Gigabit 2-Gigabit 4-Gigabit Nominal Bit Rate MBaud MBaud 4.25 MBaud Bit Rate Tolerance ± khz ± khz ± 425 Khz Table 1 - Bit Rate Test Setup: See Appendix 9.A. Test Procedure: 1. Configure the DUT for the appropriate speed of operation. 2. Verify the DUT is sourcing valid FC signaling. 3. Connect the Zero Length test load to the DUT. 4. Configure the digital oscilloscope to capture at least 200,000 transmitted bits. 5. Measure the average TX signaling speed. Observable Results: a. The average signaling rate shall fall within the limits listed in Table 1. Possible Problems: None. UNH IOL Fibre Channel Consortium 8 Clause 9 4G Electrical Physical Layer Test Suite v0.21

9 Test Differential Output Voltage The University of New Hampshire Purpose: To verify that the differential output voltage of the DUT transmitter device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table 20. [3] Ibid., Table 21. [4] Ibid., Sub-clause Resource Requirements: See Appendix 9.A Last Modification: November 30, 2005 Discussion: Reference [4] states the minimum and maximum voltage required for a 4G FC device. Reference [2] states the requirements for 1 and 2 Gigabit Fibre Channel devices. 1 Gigabit 2 Gigabit 4 Gigabit Compliance Point Min DOV Max DOV Min DOV Max DOV Min DOV Max DOV β T 600 mv 2 V 600 mv 2 V 310 mv 1.6 V δ T 650 mv 2 V 650 mv 2 V 650 mv 1.6 V γ T 1.1 V 2 V 1.1 V 2 V 310 mv 1.6 V Table 2 - Differential Output Voltage Requirements Test Setup: See Appendix 9.A. Test Procedure: 1. Configure the DUT for appropriate speed of operation. 2. Instruct the DUT to transmit valid FC signaling. 3. Connect the Zero-Length test load to the DUT transmitter device. 4. Capture the waveform on the oscilloscope and compute the differential output voltage. 5. For 4G devices at the β T and γ T compliance points, replace the Zero-Length test load with the TCTF test load and repeat step 4. Observable Results: a. The differential output voltage shall fall within the limits in Table 2 Possible Problems: None. UNH IOL Fibre Channel Consortium 9 Clause 9 4G Electrical Physical Layer Test Suite v0.21

10 Test Rise and Fall Times The University of New Hampshire Purpose: To measure the rise and fall times of the DUT s transmitter. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table20. Resource Requirements: See Appendix 9.A Last Modification: November 30, 2005 Discussion: Reference [1] specifies the TX signal characteristics for Fibre Channel electrical devices. This specification includes conformance and informative specifications for the minimum rise/fall times of the transmitter device. The specification states that the rise/fall times are to be measured from 20% to 80% of the transition while transmitting the D21.5 data codeword on the physical link. (Note that part of the CJTPAT test pattern may be used for this purpose). 1 Gigabit 2 Gigabit 4 Gigabit Compliance Point Max Rise Time (ps) Min Rise Time (ps) Max Rise Time (ps) Min Rise Time (ps) Max Rise Time (ps) Min Rise Time (ps) β T N/A 60 (Informative) δ T N/A N/A N/A N/A γ T N/A 60 (Informative) Table 3 - Rise Time Requirements Test Setup: See Appendix 9.A. Test Procedure: 1. Configure the DUT for the appropriate speed of operation. 2. Instruct the DUT to transmit CJTPAT. 3. Connect the Zero-Length test load to the DUT. 4. Configure the digital oscilloscope to capture the waveform data. 5. Process the waveform containing the D21.5 pattern and compute the rise and fall times. 6. For 4G devices at the β T and γ T compliance points, replace the Zero-Length test load with the TCTF test load and repeat steps 4 and 5. Observable Results: a. The rise/fall times shall fall within the limits set in Table 3. Possible Problems: None. UNH IOL Fibre Channel Consortium 10 Clause 9 4G Electrical Physical Layer Test Suite v0.21

11 Test Transmitter Eye Masks The University of New Hampshire Purpose: To verify that the transmitter eye of the DUT is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Subclause [3] Ibid., Table 21 and Table 27. [4] Ibid., Figure 37 Transmitter eye diagram mask. Resource Requirements: See Appendix 9.A Last Modification: November 30, 2005 Discussion: The transmitter pulse shape characteristics are specified in the form of a mask of the transmitter eye diagram, shown in reference [4]. The DUT must conform to this mask. The points used to create this mask are found in reference [3]. The measurement shall be made using both the Zero-Length test load and across the TCTF test load for 4G devices, while the DUT is transmitting CJTPAT. The transmitter is required to fit the normalized and absolute eye masks. Test Setup: See Appendix 9.A. Test Procedure: 1. Configure the DUT for the appropriate speed of operation. 2. Instruct the DUT to transmit CJTPAT. 3. Connect the Zero-Length test load to the DUT transmitter device. 4. Configure the oscilloscope to capture the waveform data and place these waveforms into the normalized and absolute mask definitions. 5. Process the captured waveform, observing the number of mask violations. 6. For 4G devices at the β T and γ T compliance points, replace the Zero-Length test load with the TCTF test load and repeat steps 4 5. Observable Results: a. The waveform shall not violate the absolute or normalized eye masks at any point for any test load case. Possible Problems: None. UNH IOL Fibre Channel Consortium 11 Clause 9 4G Electrical Physical Layer Test Suite v0.21

12 Test TX Jitter Purpose: To verify that the jitter of the DUT transmitter device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table 27. [3] Ibid., Clause 9.11 Resource Requirements: See Appendix 9.A Last Modification: November 30, 2005 Discussion: Reference [2] describes the maximum peak to peak deterministic and total transmit jitter for Fibre Channel electrical devices. The total jitter is the sum of deterministic and random jitter. These jitter values are specified at the probability. For 4G FC devices, reference [3] states that the transmit jitter shall be verified under two conditions, once using the Zero-Length test load, and again using the TCTF test load specified in reference [3]. 1 Gigabit 2 Gigabit 4 Gigabit Compliance Point DJ (UIpp) TJ (UIpp) DJ (UIpp) TJ (UIpp) DJ (UIpp) TJ (UIpp) β T δ T γ T Table 4 - TX Jitter Requirements Test Setup: See Appendix 9.A Test Procedure: 1. Configure the DUT for the appropriate speed of operation. 2. Instruct the DUT to transmit CJTPAT. 3. Connect the Zero-Length test load to the DUT transmitter device. 4. Capture the waveform on the oscilloscope and compute the jitter values. 5. For 4G devices at the β T and γ T compliance points, replace the Zero-Length test load with the TCTF test load and repeat step 4. Observable Results: a. The deterministic jitter shall not exceed the values shown in Table 4. b. The total jitter shall not exceed the values shown in Table 4. Possible Problems: None. UNH IOL Fibre Channel Consortium 12 Clause 9 4G Electrical Physical Layer Test Suite v0.21

13 Test TX RMS Common Mode Voltage (4G Only) Purpose: To verify that the RMS common mode voltage of the DUT transmitter device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table 20. Resource Requirements: See Appendix 9.A Last Modification: July 12, 2005 Discussion: Reference [2] describes the maximum common mode voltage the transmitter shall produce. The common mode voltage is defined as the addition of the V+ and V- signals. The RMS voltage waveform produced from this addition shall never surpass the maximum RMS common mode voltage specified at any point. Test Setup: See Appendix 9.A. Test Procedure: 1. Configure the DUT for 4Gbps operation. 2. Instruct the DUT to transmit valid FC signaling. 3. Connect the Zero-Length test load to the DUT transmitter device. 4. Capture the waveform on the oscilloscope and compute the RMS common mode voltage. 5. Replace the Zero-Length test load with the TCTF test load and repeat step 4. Observable Results: a. The RMS common mode voltage shall never exceed 30mV for either test load case. Possible Problems: None. UNH IOL Fibre Channel Consortium 13 Clause 9 4G Electrical Physical Layer Test Suite v0.21

14 Test TX Skew (1 & 2G Only) The University of New Hampshire Purpose: To verify that the skew of the DUT transmitter device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table 20. Resource Requirements: See Appendix 9.A Last Modification: November 30, 2005 Discussion: Reference [2] describes the skew requirements for one and two gigabit differential drivers. Skew is defined to be the time difference between the means of the midpoint crossing times of the TX+ signal and the TX- signal. Compliance Point 1 Gigabit Max Skew (ps) 2 Gigabit Max Skew (ps) β T δ T 20 N/A γ T Table 5 - TX Skew Requirements Test Setup: See Appendix 9.A. Test Procedure: 1. Configure the DUT for the appropriate speed of operation. 2. Instruct the DUT to transmit valid FC signaling. 3. Connect the Zero-Length test load to the DUT transmitter device. 4. Capture the waveform on the oscilloscope and compute the skew between the TX+ and TX- signals. Observable Results: a. The skew shall never exceed the values shown in Table 5. Possible Problems: None. UNH IOL Fibre Channel Consortium 14 Clause 9 4G Electrical Physical Layer Test Suite v0.21

15 GROUP 2: β Point 4-Gigabit Return Loss Verification Overview: This group of tests verifies the return loss specifications at the β T compliance point for 4-Gigabit Fibre Channel devices, as defined in Clause 9 of FC-PI-2. All of the tests described in this section are currently undergoing development at the University of New Hampshire. Comments and questions regarding the implementation of these tests are welcome, and may be forwarded to the Fibre Channel Consortium at the UNH (fcclab@iol.unh.edu). UNH IOL Fibre Channel Consortium 15 Clause 9 4G Electrical Physical Layer Test Suite v0.21

16 Test Transmitter Differential Mode Return Loss Purpose: To verify the differential mode return loss of the DUT transmitter device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table23. Resource Requirements: See Appendix 9.A Last Modification: July 12, 2005 Discussion: Reference [2] describes the transmitter differential mode return loss specifications at all compliance points. Reference [1] describes impedance characteristics for 4G FC in terms of return loss instead of an impedance profile. A conformant device shall not violate the spectral limit line as specified by reference [2]. Test Setup: See Appendix 9.A Test Procedure: 1. Configure the DUT for 4Gbps operation. 2. Instruct the DUT to transmit valid FC data. 3. Connect the DUT to the VNA using the appropriate FC -> SMA test fixture. 4. Measure the differential mode return loss of the DUT transmitter device. Observable Results: a. The differential mode return loss of the DUT transmitter device at the β T compliance point shall be greater than 12dB from 50MHz to 510MHz, and greater than log 10 (f/2.125ghz) db from 510MHz to 3.2GHz. Possible Problems: None. UNH IOL Fibre Channel Consortium 16 Clause 9 4G Electrical Physical Layer Test Suite v0.21

17 Test Transmitter Common Mode Return Loss The University of New Hampshire Purpose: To verify the common mode return loss of the DUT transmitter device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table23. Resource Requirements: See Appendix 9.A Last Modification: July 12, 2005 Discussion: Reference [2] describes the transmitter common mode return loss specifications at all compliance points. Reference [1] describes impedance characteristics for 4G FC in terms of return loss instead of an impedance profile. A conformant device shall not violate the spectral limit line as specified by reference [2]. Test Setup: See Appendix 9.A Test Procedure: 1. Configure the DUT for 4Gbps operation. 2. Instruct the DUT to transmit valid FC data. 3. Connect the DUT to the VNA using the appropriate FC -> SMA test fixture. 4. Measure the common mode return loss of the DUT transmitter device. Observable Results: a. The common mode return loss of the DUT transmitter device at the β T compliance point shall be greater than 12dB from 50MHz to 340MHz, and greater than log 10 (f/2.125ghz) db from 340MHz to 3.2GHz. Possible Problems: None. UNH IOL Fibre Channel Consortium 17 Clause 9 4G Electrical Physical Layer Test Suite v0.21

18 Test Receiver Differential Mode Return Loss The University of New Hampshire Purpose: To verify the differential mode return loss of the DUT receiver device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table23. Resource Requirements: See Appendix 9.A Last Modification: July 12, 2005 Discussion: Reference [2] describes the receiver differential mode return loss specifications at all compliance points. Reference [1] describes impedance characteristics for 4G FC in terms of return loss instead of an impedance profile. A conformant device shall not violate the spectral limit line as specified by reference [2]. Test Setup: See Appendix 9.A Test Procedure: 1. Configure the DUT for 4Gbps operation. 2. Instruct the DUT to transmit valid FC data. 3. Connect the DUT to the VNA using the appropriate FC -> SMA test fixture. 4. Measure the differential mode return loss of the DUT receiver device. Observable Results: a. The differential mode return loss of the DUT receiver device at the β T compliance point shall be greater than 12dB from 50MHz to 510MHz, and greater than log 10 (f/2.125ghz) db from 510MHz to 3.2GHz. Possible Problems: None. UNH IOL Fibre Channel Consortium 18 Clause 9 4G Electrical Physical Layer Test Suite v0.21

19 Test Receiver Common Mode Return Loss The University of New Hampshire Purpose: To verify the common mode return loss of the DUT receiver device is within the conformance limits. References: [1] FC-PI-2/Project 1506-D/Rev10.0, Clause 9. [2] Ibid., Table23. Resource Requirements: See Appendix 9.A Last Modification: July 12, 2005 Discussion: Reference [2] describes the receiver common mode return loss specifications at all compliance points. Reference [1] describes impedance characteristics for 4G FC in terms of return loss instead of an impedance profile. A conformant device shall not violate the spectral limit line as specified by reference [2]. Test Setup: See Appendix 9.A Test Procedure: 1. Configure the DUT for 4Gbps operation. 2. Instruct the DUT to transmit valid FC data. 3. Connect the DUT to the VNA using the appropriate FC -> SMA test fixture. 4. Measure the common mode return loss of the DUT receiver device. Observable Results: a. The common mode return loss of the DUT receiver device at the β T compliance point shall be greater than 12dB from 50MHz to 340MHz, and greater than log 10 (f/2.125ghz) db from 340MHz to 3.2GHz. Possible Problems: None. UNH IOL Fibre Channel Consortium 19 Clause 9 4G Electrical Physical Layer Test Suite v0.21

20 GROUP 3: Impedance Verification The University of New Hampshire Overview: This group of tests verifies the impedance specifications for one and two gigabit Fibre Channel devices, as defined in Clause 9 of FC-PI-2. All of the tests described in this section are currently undergoing development at the University of New Hampshire. Comments and questions regarding the implementation of these tests are welcome, and may be forwarded to the Fibre Channel Consortium at the UNH (fcclab@iol.unh.edu). As of February 28, 2006 this group of tests is still under development. UNH IOL Fibre Channel Consortium 20 Clause 9 4G Electrical Physical Layer Test Suite v0.21

21 APPENDICES The University of New Hampshire Overview: Test suite appendices are intended to provide additional low-level technical detail pertinent to specific tests contained in this test suite. These appendices often cover topics that are outside of the scope of the standard, and are specific to the methodologies used for performing the measurements defined in this test suite. Appendix topics may also include discussion regarding a specific interpretation of the standard (for the purposes of this test suite), for cases where a particular specification may appear unclear or otherwise open to multiple interpretations. UNH IOL Fibre Channel Consortium 21 Clause 9 4G Electrical Physical Layer Test Suite v0.21

22 Appendix 9.A - Hardware Requirements, Test Fixtures, and Setups Purpose: To specify the measurement hardware, test fixtures, and setups used in this test suite. References: [1] FC-PI-2 Standard Clause 9 [2] Ibid., Subclause TCTF Overview [3] Ibid., Subclause Test Loads [4] Ibid., Subclause Transmitter Device Characteristics [5] Ibid., Subclause Receiver Characteristics Last Modification: July 8, 2005 (version 1.0) Discussion: 9.A.1 - Introduction Clause 9 of FC-PI-2 defines several test fixtures that are required for performing the physical layer tests covered in that Clause 9. The purpose of this appendix is to present a reference implementation of these test fixtures, and to specify the test equipment and setups used by the UNH IOL for performing the tests as defined in this test suite. 9.A.2 - Equipment Table 9.A-1 below summarizes the list of measurement equipment used by the UNH IOL for performing the tests contained in this test suite. Functional Block Equipment Key Features Digital Storage Oscilloscope Agilent DSO81304A 13GHz 4 Channel Real Time DSO Vector Network Analyzer Agilent N4446A 20GHz, full 4-port mixed-mode S-parameters 9.A.3 - Fixture Requirements Table 9.A-1: Equipment list testing: There are two test fixtures defined in Clause 9 of the FC-PI-2 Standard for the purpose of physical layer - Zero-Length test load - TCTF test load Each of these fixtures incorporates an FC connector at one end, plus some network of passive elements that present a particular load termination to the FC device. Also, reference points are defined from which the measurements shall be made. In addition, some sort of adapter fixture will be needed to connect the DUT transmitter and receiver ports to the VNA for performing the return loss tests of Group 2. (As it turns out, a portion of the Zero-Length test fixture can be reused for this purpose, which will be shown later.) UNH IOL Fibre Channel Consortium 22 Clause 9 4G Electrical Physical Layer Test Suite v0.21

23 Some of the tests in this test suite must be performed twice, once using the Zero-Length test load, and again using the TCTF test load. Other tests are defined for only one measurement case. Table 9.A-2 below summarizes the fixtures required for each test, and indicates the tests that require multiple fixtures. Table 9.A-2: Fixture Requirements Per Test Test Name Fixture 1 Fixture TX Bit Rate Zero-Length Differential Output Voltage Zero-Length TCTF Rise and Fall Times Zero-Length TCTF Transmitter Eye Mask Zero-Length TCTF TX Jitter Zero-Length TCTF TX RMS Common Mode Voltage Zero-Length TCTF TX Skew Zero-Length Transmitter Differential Mode Return Loss Zero-Length Transmitter Common Mode Return Loss Zero-Length Receiver Differential Mode Return Loss Zero-Length Receiver Common Mode Return Loss Zero-Length - 9.A.4 - Fixture Implementations In general, the fixtures may be viewed as having three sections: 1) a small PCB to convert the FC-specific connector to SMA, 2) a physical channel that represents the TCTF (which may be omitted for the Zero-Length case), and 3) a termination element. By substituting (or removing) each of these elements, all of the fixture cases can be implemented with a relatively small number of components. Zero-Length Test Load The Zero-Length test load is the simplest of the fixtures. Figure 9.A-1 below shows a copy of the Zero- Length test load diagram found in Clause 9 of FC-PI-2 [3] for differential 100 Ω variants. Figure 9.A-1: 200 and 400-DF-EL-S Intra cabinet Zero-Length test load UNH IOL Fibre Channel Consortium 23 Clause 9 4G Electrical Physical Layer Test Suite v0.21

24 One implementation of this fixture could involve physical resistors and capacitors on a PCB that contains the appropriate FC connector. Probe points would need to be included in order to attach a high-impedance differential probe, which would also be required. Note that a functionally equivalent implementation of this fixture can be realized by simply sending the Tx+ and Tx- signals directly into two separate channels of the DSO, through the specified DC blocking capacitors (if they are not already present on the DUT transmitter.) The DSO inputs themselves act as the 50-ohm terminating loads, with the probe points effectively being the input ports of the DSO. This configuration provides the benefit of not requiring a high-impedance active differential probe, and also results in a slightly enhanced vertical resolution. (In this configuration, the full quantizer range is applied to each half of the differential signal, as opposed to the case when a differential probe is used, where the entire quantizer range is applied across the full differential signal.) The two-channel method requires that the two channels be subtracted inside the DSO (or in the post-processing software) in order to create the differential signal. While the DSO acts as the termination component of the differential 100Ω Zero-Length test fixture, a separate adapter PCB must also be used to convert the FC-specific connector type to SMA (i.e., the connector type found on the inputs of the DSO). The UNH IOL is currently developing these fixture types. The setup for tests involving the Zero-Length test load would then be as follows: DUT FC-to-SMA adapter DSO TCTF Test Load Next, consider the TCTF test load required for four gigabit devices. Figure 9.A-2 below shows a copy of the TCTF test load diagram from FC-PI-2 [1]: Figure 9.A-2: TCTF test load diagram Note that this diagram is similar to the Zero-Length test load, but has the added TCTF (Transmitter Compliance Transfer Function) component. FC-PI-2 specifies that, The TCTF is the mathematical statement of the transfer function that the transmitter shall be capable of producing acceptable signals as defined by the receive mask. [2] The implementation of the TCTF test load then simply involves adding a physical TCTF channel to the Zero-Length test fixture setup, between the FC-to-SMA adapter and the DSO. The setup then becomes: DUT FC-to-SMA adapter Compliance Interconnect DSO It should also be noted that a valid Compliance Interconnect is defined as any channel that meets or exceeds the minimum loss requirements for the particular specification. Two separate loss curves are defined for FC UNH IOL Fibre Channel Consortium 24 Clause 9 4G Electrical Physical Layer Test Suite v0.21

25 (one for intra cabinet and one for inter cabinet), and a valid Compliance Interconnect is any physical channel that is at least as lossy as the limit line, or more so. For the intra cabinet TCTF requirements, the UNH IOL uses a PCB containing approximately 36 inches of FR-4 trace. The PCB in combination with two HMZD adaptors and SMA test cables to each end of the PCB is sufficient to make the entire channel fall below the intra cabinet TCTF curve. The addition of the SMA cabling can add noticeable losses, which should be taken into account for this application. If one were to start with a channel that by itself meets the TCTF requirement, the added cabling could unfairly penalize a DUT that might be on the edge of conformance. While in general, it is desirable to build as much margin as possible into any device, for the purposes of conformance testing, care must be taken not to use a Compliance Interconnect that is too lossy (above and beyond the minimum required loss) and risk falsely failing devices that may technically be conformant, but may not have excessive margin. The intra cabinet TCTF PCB is shown in Figure 9.A-3, below. Figure 9.A-4 shows the frequency response of this channel with the added SMA cables. Figure 9.A-3: Intra Cabinet TCTF Compliance Interconnect, including cables (Tyco XAUI Test Backplane) UNH IOL Fibre Channel Consortium 25 Clause 9 4G Electrical Physical Layer Test Suite v0.21

26 Figure 9.A-4: Intra Cabinet TCTF Compliance Interconnect Frequency Response The Inter Cabinet TCTF limit line specification is different than the Intra Cabinet limit line, and more accurately reflects the loss characteristics of the cabling used in these systems. The UNH IOL does not currently possess an Inter Cabinet TCTF. VNA Test Setup All of the tests in Group 2 of the test suite use the same test setup (and are performed in a single measurement) using an Agilent 4-port, 20GHz Vector Network Analyzer, shown below in Figure 9.A-5. The port notation convention used by the UNH IOL assumes the RX pair of the DUT to be connected to Differential Port 1 of the VNA, and the DUT TX pair connected to Differential Port 2. (An easy way to remember this convention is to think of the DUT as being analogous to a passive 2-port filter device, whereby the input (RX) port of the filter is traditionally connected to Port 1 of the 2-port VNA, and the output (TX) port is connected to Port 2.) Furthermore, a polarity convention is used whereby single-ended ports 1 and 2 are always the positive polarity components of Differential Ports 1 and 2, respectively. Table 9.A-3 below, summarizes the port configuration setup for the VNA. UNH IOL Fibre Channel Consortium 26 Clause 9 4G Electrical Physical Layer Test Suite v0.21

27 Table 9.A-3: VNA port assignments for return loss test setup VNA Differential Port VNA Single-Ended Ports DUT Ports Diff Port 1 SE Port 1 (upper left) RX+ (upper pair on VNA) SE Port 3 (upper right) RX- Diff Port 2 SE Port 2 (lower left) TX+ (lower pair on VNA) SE Port 4 (lower right) TX- Figure 9.A-5: VNA Test Setup Figure 9.A-6 below shows a screen shot of the MultiPort software, showing frequency domain mode of operation. For all receiver tests, the data is displayed in terms of reflection (common mode or differential), based on the reflective parameters SDD11, SDD22, SCC11, and SCC22. Figure 9.A-6: MultiPort Software Screen Capture (Differential S-parameter display shown) UNH IOL Fibre Channel Consortium 27 Clause 9 4G Electrical Physical Layer Test Suite v0.21

28 9.A.5 - Conclusion In this appendix, reference implementations for all of the FC tests defined in this suite have been presented. A modular approach has been employed in order to simplify the setup. Images have been provided showing the specific adapter fixtures used by the UNH IOL. Specific details regarding the Intra Cabinet TCTF channel used by the IOL have been presented, including insertion loss characteristics. Together these components can be combined to create any of the fixtures specified by FC-PI-2 for performing these tests. UNH IOL Fibre Channel Consortium 28 Clause 9 4G Electrical Physical Layer Test Suite v0.21