[Fwd: Re: SPI-2 driver waveform]
Walter Bridgewater x2371
wally at eng.adaptec.com
Thu May 15 14:39:08 PDT 1997
* From the SCSI Reflector (scsi at symbios.com), posted by:
* wally at eng.adaptec.com (Walter Bridgewater x2371)
I'm sorry, I should have explained that the 3rd 0.2Vss is for the
20% point for rise/fall times, as is the 0.8Vss right next to it.
Also, remember that 'Vss' means something like
"voltage signal swing" and not ground.
> Then look closely at the three references to the 0.2Vss at the negative
> level for overshoot. There is one too many. Specifically, the one to
> the farthest right. It is drawn between the threshold level and the
> stabilized level.
> This is what my drawing looks like and it doesn't make sense.
> I believe the figure is correct. Figure 33 is used to show to
> different things:
> 1) show the over/under shoot levels
> 2) show where the 20% & 80% points are for rise/fall times
> > In the X3T10/1142D Rev.11 document I think there is an error in the
> > waveform drawing on page 50. Figure 33.
> > At the negative voltage level, there are three references to 0.2Vss for
> > overshoot spikes. It seems to me that there should be only two
> > references, the same as shown at the positive voltage level.
> > Secondly, the reference arrowhead for 0.8Vss is shown at the wrong point
> > at the negative level.
> > If I am wrong and the drawing as shown is correct, can someone explain
> > why it has to be this way.
> > Thanks,
> > Alan.
> > *
> * For SCSI Reflector information, send a message with
> * 'info scsi' (no quotes) in the message body to majordomo at symbios.com
* For SCSI Reflector information, send a message with
* 'info scsi' (no quotes) in the message body to majordomo at symbios.com
More information about the T10