SSC Applied High-speed Serial Interface Signal Generation and Analysis by Analog Resources. Hideo Okawara Verigy Japan K.K.

Transcription

1 SSC Applied High-speed Serial Interface Signal Generation and Analysis by Analog Resources Hideo Okawara Verigy Japan K.K. 1

2 Purpose High-speed Serial Interface SSC Applied Signal Waveform Application of Analog Resources Generation by a UHF AWG Analysis by a Waveform Sampler 2

3 Outline Introduction Signal Generation Signal Analysis SSC Applied Clock SSC Applied Align Primitive Conclusion 3

4 SSC Spread Spectrum Clocking Magnitude Original Fixed Clock Magnitude Peak Reduced SSC Applied Clock Fc Frequency Fc Frequency 4

5 1.5Gbps SATA SSC Spec. 30us.. 33us (30kHz..33kHz) 1, Bit Rate [Mbps] 1, MHz 0.5% Down Spread 3.35ps Unit Interval [ps]

6 Data Structure 10-bit Word 8b10b Conversion Align Primitive (40 bits) Words 6

7 Increasing/Decreasing Period ~15us #1 3.35ps #0 Min. 667ps 0.148fs ~30us 45,360 bits =4,536x10 =1,134x40 ~15us #22,678 #22,679 #22,680 #22,681 #45,358 #45,359 Max. 670ps Min. 667ps 7

8 Elastic UI Amplitude Square Shape 0.148fs Exponential Curve Sampling Timing 8

9 Outline Introduction Signal Generation Signal Analysis SSC Applied Clock SSC Applied Align Primitive Conclusion 9

10 Signal Programming Steps 1 SSC Cycle (30 usec) Digital Data Rolled-off Waveform Filtered Waveform AWG Waveform Total 45,360 bits (@ 1.5Gbps) Conversion 1,048,576=2 20 points (@ 34.6Gsps) Filtering 1,048,576=2 20 points (@ 34.6Gsps) Re-sampling 124,288 points (@ 4.1Gsps) 10

11 Initial Rolled-off Waveform 1 UI Exponential Curve Amplitude Data 0 (1 to 0 Transition) Data 1 (0 to 1 Transition) ~23 points 34.6Gsps 11

12 Extract Main Lobe by Filtering Initial Spectrum Magnitude [db] Frequency [GHz] Band-limited Spectrum 1.5GHz 12

13 Re-sampling (a) Initial 1,048, Gsps Amplitude (b) Main Lobe 1,048, Gsps (c) Re-sampled 124, Gsps Address 13

14 Typical Test Signal Data MHz Clock 375MHz Clock Align Primitive PRBS Words 14

15 Generated Signal Spectrum Clock 3.75MHz Align Primitive 750MHz 1GHz PRBS Word Spectrum Analyzer: Agilent E4440A 1GHz 15

16 Generated Signal Waveform Digital Signal Oscilloscope: Agilent Infiniium DSA91304A 13GHz 16

17 Generated Signal Waveform Digital Signal Oscilloscope: Agilent Infiniium DSA91304A 13GHz 17

18 Outline Introduction Signal Generation Signal Analysis SSC Applied Clock SSC Applied Align Primitive Conclusion 18

19 Experimental Configuration (A) 4.1Gsps Fs= Msps UHF AWG 124,288 points 750MHz Clock with 33kHz SSC Waveform Sampler N=16,384 points 19

20 Spectrum in Under-sampling 0 Front Page Back Page Front Page Back Page Front Page Back Page Front Page Baseband Fs/2 N/2 Frequency Domain Fs N 2N 3N Frequency Bin # M Folding all pages. Spectrum Display Baseband Baseband Baseband 0 N/2 0 N/2 0 N/2 20

21 Amplitude [V] Time [us] Waveform and Spectrum Waveform 750MHz Clock Spectrum Fs= Msps N=16,384 points 3.75MHz Magnitude [db] (Baseband) Frequency [MHz] 21

22 Orthogonal Demodulation Post Processing in the Computer LPF Re DUT Sampler cos Im Re F ref tan -1 ( ) sin LPF Im Φ(t) +π -π dφ dt f(t) 22

23 Test Signal Waveform: ODM by Equations Reference Multiplication: g(t) cos(ω r t) = A {cos((ω-ω r )t+θ)+sin((ω+ω r )t+θ)} 2 g(t) (-sin(ω r t))= A {sin((ω-ω r )t+θ)-cos((ω+ω r )t+θ)} 2 Low Pass Filtering: Arctangent: arctan y(t) x(t) g(t)=acos(ωt+θ) x(t)= A cos((ω-ω r )t+θ) 2 A y(t)= 2 sin((ω-ω r )t+θ) = (ω-ω r )t+θ = Φ(t) Differentiation: dφ dt =ω-ω r 23

24 Reference Multiplication Magnitude [db] Reference (748.12MHz) Initial Spectrum Magnitude [db] Beat Sum Frequency [MHz] 24

25 Reference Multiplication Magnitude [db] Reference (748.12MHz) Initial Spectrum Magnitude [db] Low Pass Filter -70 Beat Sum Frequency [MHz] 25

26 Instantaneous Phase arctan Beat(sin) Beat(cos) ω ω r t + θ 0 Phase [rad] Time [us] 26

27 SSC Frequency Trend d dt ω ω r t + θ ω ω r Frequency [MHz] MHz 30us Time [us] 27

28 Spectrum of SSC Trend 0 Fundamental (33kHz) Magnitude [db] Frequency [MHz]

29 Ideal Triangle Subtraction Frequency [MHz] Reconstructed SSC Trend -2.0 A {cos(ωt )+ 1 9 cos(3ωt )+ 1 cos(5ωt )+ } 25 Ideal Triangle Waveform 0.1 Residual Noise Waveform Time [us] 29

30 Original Spectrum 0 Magnitude [db] Frequency [MHz]

31 Residual Noise Spectrum 0 Magnitude [db] Frequency [MHz]

32 Outline Introduction Signal Generation Signal Analysis SSC Applied Clock SSC Applied Align Primitive Conclusion 32

33 Experimental Configuration (B) 4.1Gsps Fs=99.04Msps UHF AWG points Align Primitive with 33kHz SSC Waveform Sampler N=16384 points 33

34 Spectrum of Align Primitive 123 1GHz 2 7.5MHz x 1 40 = ~0.19MHz MHz x = ~7.5MHz

35 Signal in Under-sampling Frequency Domain 0 N/2 Fs N 2N 3N Folding Entire Spectra Overlap 0 N/2 N/2 0 0 N/2 35

36 Spectrum of Align Primitive -20 Magnitude [db] Frequency [MHz] 36

37 Frequency Trend MHz 0.38MHz 0.56MHz Frequency [MHz] MHz 0.94MHz 1.1MHz 30us MHz 37

38 Outline Introduction Signal Generation Signal Analysis SSC Applied Clock SSC Applied Align Primitive Conclusion 38

39 Conclusion UHF AWG generates SSC applied signal. SSC Applied Clock SSC Applied Align Primitive SSC Applied PRBS Encoded Words Waveform Sampler analyzes limited SSC applied signal. SSC Applied Clock: Spectrum & SSC Trend SSC Applied Align Primitive: SSC Trend 39

40 Thank you for your attention. 40