Data Sheet

USBProtocolSuiteUserManual 481
LinkTracker(3.1) TeledyneLeCroyCorporation
10.9 Link Tracker (3.1)
TheLinkTrackerwindowdisplaysadetailedchronologicalviewofevents.Eventsare
shownonachannel‐by‐channelbasisincolumnswithinthewindow.
Figure 10.28: Link Tracker Window
Youcanselectthenumberofcolumnstoviewmoreorlessdataatonetime.
EachtimeslotintheverticalaxisrepresentstheminimumtimethataDWORDrequiresto
traversethebuswhenthe"Columns"isselectedas4.
Note:OnSymbolDisplays:Therewilloccasionallybe"blank"symbolsinsertedintotheLinkTracker
display(orsymbolsremoved)tocompensatefortimestampratematchingbetweenthevarious
timebases.Thishastodowiththeproblemthatthereare3clockdomains(Rx,Tx,andour
precisiontimestamp)thatneedtoberepresentedinthetrace.Thenominal2nSec/symbol
TransmitandReceiveclockscanvaryupto500ppmpertheUSBSpecification,whereasthe
Analyzerisaccurateto3ppm.Blankentriesandmissingentriesinthelinktrackerarethereto
compensateforthisdifference,andtotrytomaintainthemostaccuraterelationshipamongst
theseclocksandpresenttheclosesttimerelationshipbetweenthedownwardstreamandthe
upwardstream.TheclocklistedintheTimecolumnisourprecision3ppmclocktimestamp.
Toolbar:PresentsbuttonsforchangingtheformatoftheLinkTrackerwindow.
MainDisplayArea:Displaystrafficchronologicallyasitoccurredintherecording.The
windowdividesintocolumns:thefirstcolumnshowstimeandtrafficisshownona
channel‐by‐channelbasisinthecolumnsontheright.