[Trac #273] Strange Hardware Signaling Voltages

[Zarro Boogs per Child]

#273: Strange Hardware Signaling Voltages
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 Reporter:  JordanCrouse  |        Owner:  mfoster
     Type:  defect        |       Status:  new    
 Priority:  blocker       |    Milestone:  BTest-1
Component:  hardware      |   Resolution:         
 Keywords:                |  
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Changes (by JordanCrouse):

  * owner:  JordanCrouse => mfoster

Comment:

 We have no explanation for the apparent amplitudes of signaling. There
 is no way the 5536 can signal this high as it only gets ground and 3.3
 VDC.  Perhaps there is some setup or instrumentation error regarding the
 apparent measured amplitude.

 The pulses on the right that occur every millisecond are Start of Frame
 (SOF) from host controller to device.  These are normal.

 The signaling from left to just past middle is unusual.  Since this is a
 trace of a HS device getting detected as FS, this could be then end of
 the misdetect sequence (chirp and chirp response failure).  Hard to say.

 Attached are scope shots of normal operation for comparison.

 If this can be re-created here, we will work it.  Reassigning temporarily
 to Mark to get some more information on recreating the issue.

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Ticket URL: <http://dev.laptop.org/ticket/273#comment:1>
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