Tesla, This Intel paper was at DesignCon 2009, titled "Switching Voltage Regulator Noise Coupling Analysis for Printed Circuit Board Systems" by Amy Luoh, Gene Garrison and Jon Powell. BTW low-speed buses often fail because people focus on the most challenging, highest-speed interconnects and then time runs out in the design schedule. Best regards, Istvan Novak Oracle On 8/28/2012 6:00 AM, Tesla wrote: > Hi, Steve > > Thanks a lot > > Would you give a link about the intel paper you mentioned? Be interested to > read it. > > Regards. > > Tesla > > > > > At 2012-08-28 16:15:37,"steve weir" <weirsi@xxxxxxxxxx> wrote: >> If one is dealing with data signals, then as long as they settle out at >> valid logic levels by the time they are sampled, and remain stable long >> enough to satisfy hold time requirements, then all is good. That >> observation has lulled many a digital engineer into "Sauron's Happy >> Fun-Time Intermittent Failure Party at Mount Doom"(tm) when they neglect >> the fact that not all low-rate signals are data. Some low-rate signals >> are timing strobes, such as TCLK on a JTAG bus. Timing strobes not only >> have to settle-out at valid levels, they need to be free of waveform >> artifacts like double transitions. >> >> Then there are high impedance dinosaur busses that say: "Hey sailor: >> For $20 dollars I'll take your induced noise around the world." A few >> years ago Intel presented a DesignCon paper where they described >> spending the better part of a million dollars on manpower and >> sophisticated software tools, as well as nearly half a year tracking >> down signal integrity problems on a lowly I2C bus. Every month or two >> induced noise would cause servers to reset. >> >> Steve. >> >> >> On 8/28/2012 12:23 AM, Rohit MISHRA wrote: >>> Rajneesh, >>> >>> That's a good question, indeed !! >>> >>> You rightly pointed out that slow repetition pulses driven by fast driver >>> can also have reflections & other transmission line effects but you should >>> also understand that these effects create signal integrity problems most >>> when they have less time to settle. >>> >>> The signal pulse width and duty cycle are not factors in deciding >>> transmission line behavior such as reflections but when you use high pulse >>> width i.e. low bit rate signal, you are also giving more time to settle >>> these effects before sampling at receiver end and remember, what the signal >>> looks like at sampling that matters most ! >>> >>> Hope that helps. >>> >>> >>> Rohit Mishra >>> >>> >>> >>> -----Original Message----- >>> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On >>> Behalf Of rajneesh shukla >>> Sent: Tuesday, August 28, 2012 12:29 PM >>> To: si-list@xxxxxxxxxxxxx >>> Subject: [SI-LIST] Rise/Fall time Vs Bit rate. >>> >>> Experts, >>> We all have read that in high speed design it's rise time that creates >>> signal integrity issue. By this theory, all low bit rate signals that >>> is driven by fast I/O driver will also have signal integrity issues then >>> why most of the time high bit rate signals are analysed for signal >>> integrity issue ?? >>> >>> Please explain what is the role of bit rate in signal integrity ?? >>> >>> Rajneesh >>> >>> >>> ------------------------------------------------------------------ >>> To unsubscribe from si-list: >>> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >>> >>> or to administer your membership from a web page, go to: >>> //www.freelists.org/webpage/si-list >>> >>> For help: >>> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >>> >>> >>> List forum is accessible at: >>> http://tech.groups.yahoo.com/group/si-list >>> >>> List archives are viewable at: >>> //www.freelists.org/archives/si-list >>> >>> Old (prior to June 6, 2001) list archives are viewable at: >>> http://www.qsl.net/wb6tpu >>> >>> >>> ------------------------------------------------------------------ >>> To unsubscribe from si-list: >>> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field >>> >>> or to administer your membership from a web page, go to: >>> //www.freelists.org/webpage/si-list >>> >>> For help: >>> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >>> >>> >>> List forum is accessible at: >>> http://tech.groups.yahoo.com/group/si-list >>> >>> List archives are viewable at: >>> //www.freelists.org/archives/si-list >>> >>> Old (prior to June 6, 2001) list archives are viewable at: >>> http://www.qsl.net/wb6tpu >>> >>> >>> >> >> -- >> Steve Weir >> IPBLOX, LLC >> 150 N. Center St. #211 >> Reno, NV 89501 >> www.ipblox.com >> >> (775) 299-4236 Business >> (866) 675-4630 Toll-free >> (707) 780-1951 Fax >> >> All contents Copyright (c)2012 IPBLOX, LLC. All Rights Reserved. >> This e-mail may contain confidential material. >> If you are not the intended recipient, please destroy all records >> and notify the sender. >> >> ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu