De presentatie wordt gedownload. Even geduld aub

De presentatie wordt gedownload. Even geduld aub

--1-- An exploration of synchronization solutions for parallel short-range optical interconnect in mesochronous systems Harald Devos.

Verwante presentaties


Presentatie over: "--1-- An exploration of synchronization solutions for parallel short-range optical interconnect in mesochronous systems Harald Devos."— Transcript van de presentatie:

1 --1-- An exploration of synchronization solutions for parallel short-range optical interconnect in mesochronous systems Harald Devos

2 --2-- Introduction Optical links Synchronization Designs and simulations Conclusion

3 --3-- Introduction Bitrate of electrical interconnects limited by the aspect ratio *: * D.A.B. Miller and H.M. Ozaktas use of Optical Interconnects

4 --4-- Introduction long haul short haul

5 --5-- Introduction long haul short haul BW, bitrate also latency important

6 --6-- Introduction long haul short haul BW, bitrate also latency important high density, parallel

7 --7-- Introduction long haul short haul BW, bitrate also latency important high density, parallel mesochronous Synchronization needed

8 --8-- Introduction Optical links Synchronization Designs and simulations Conclusion

9 --9-- Optical links

10 Optical links latency IN OUT

11 Optical links eye-diagram

12 Optical links Jitter: HF, LF (wander) 2J T

13 Optical links Skew S T S

14 Optical links

15 Introduction Optical links Synchronization Designs and simulations Conclusion

16 Synchronization Synchronization = move data to the local clock domain Determine the phase Adjust the phase

17 Synchronization Adjusting the phase Clk Data Auxiliary Clk

18 Synchronization Adjusting the phase Clk Data Auxiliary Clk

19 Synchronization Adjusting the phase DQDQ Clk Data Auxiliary Clk ?

20 Synchronization Auxiliary clock: one of n clock phases Clk = C1 C1 C2 C3 C4 C5 T/5 e.g. n = 5

21 Synchronization Choice of auxiliary clock T/n T/2n T/n

22 Synchronization Parallel ? T/2-J-S T S T/2n

23 Introduction Optical links Synchronization Designs and simulations Conclusion

24 Designs Parallel Serial nn f f fff n.f n n Ref. Determine phase: use of a reference link

25 Designs AMS 0,6 µm – technology, standard libraries, state-of-the-art Different phase detection: 1. AJTI: ‘artificial jitter injection’ 2. Flip-flop phase detectors

26 Designs: AJTI Determine phase with AJTI Ref. …0101… 0101

27 Designs: AJTI Determine phase with AJTI Ref. …0101… 0101 AJTI

28 Designs: AJTI Determine phase with AJTI Ref. …0101…

29 Designs: AJTI Disadvantages Reference: not flexible Initialization Extra delay

30 Designs: FF phase detectors Determine phase with flip-flop phase detector Ref. ck ckQ Suited clock phases

31 Designs: FF phase detectors Advantages Flexibility reference signal –Data signal –PRBS –Serial word synchronization

32 Designs: comparison AJTI 2 or more clock phases Extra delay Initialisation problem Ref.=010101… FF phase detectors At least 4 clock phases Minimal delay Initialisation OK Ref.= signal with transitions

33 Designs Area and Power consumption

34 Introduction Optical links Synchronization Designs and simulations Conclusion

35 Conclusion If skew en jitter are sufficiently low, synchronization can be optimized Using an extra link can simplify the circuits Greater uniformity needed to minimize skew

36 Acknowledgments Joni Dambre, Wim Meeus, Dirk Stroobandt and Jan Van Campenhout

37 --37--

38 Questions ? ?

39 --39--

40 Not mentioned Generation clock phases Influence of coding Comparison Synchronization circuits

41 Designs: flip-flop phase detector

42 Optical links Properties optical links: Latency Jitter Skew

43 Optical links Optical link

44 Optical links Soorten ontvangers: Transimpedantie versterker (TIA) - belangrijk statisch verbruik => verbruik per bit neemt af met stijgende frequentie

45 Optical links Soorten ontvangers: Geklokte versterker (sense-amplifier) - vooral dynamisch verbruik => verbruik per bit weinig afhankelijk van frequentie - zuiniger dan TIA - na bemonsteren geen ‘skew’ meer - klok nodig

46 Optical links Klok nodig Meezenden referentiesignaal extra kost extra voordeel Ook nuttig voor niet-geklokte ontvangers ?

47 Synchronization Mesochronous:

48 Designs: AJTI Voordelen,benefits profits: - Methode bruikbaar voor willekeurig aantal fasen

49 Designs: Gemeenschappelijke kenmerken Kost ~ 1/(# parallelle links) Hulpklok volgt fase bij drift Hulpklok: n e 1 e fase bit kwijt ! 1 e n e fase 2 maal zelfde bit!

50 Introduction Optical links Synchronization Designs and simulations Conclusion


Download ppt "--1-- An exploration of synchronization solutions for parallel short-range optical interconnect in mesochronous systems Harald Devos."

Verwante presentaties


Ads door Google