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From: luudee on 3 Nov 2009 00:40
On Oct 27, 10:17 pm, luudee <rudolf.usselm...(a)gmail.com> wrote:
> On Oct 27, 9:47 pm, austin <aus...(a)xilinx.com> wrote:
>
> > Rudi,
>
> > I do not know.  That is the purpose of documentation, to document.
>
> > One thought I had is that this works by measuring the difference
> > between an open line, and a terminated line, at the transmitter.  Such
> > analog measurement techniques only work for an exact fixed length of
> > the PCIe bus connection.  If you are using extension cables, or an
> > extension card, the length of the transmission lines may affect the
> > measurement.
>
> > Austin
>
> Hi Austin,
>
> I feel that in this case the documentation fails to document.
> The description for Receiver Detect is a) incomplete; and,
> b) scattered throughout unrelated sections.
>
> My understanding is that this logic works by measuring the
> time it takes to charge the coupling capacitor. (It is present and
> correct value on my board). Cable length should not matter.
>
> Receiver Detection is described starting on page 151 in ug198.
> It clearly shows a waveform diagram, where I enter powermode
> 2'b10, and the next cycle assert TXDETECTRX. And some time
> later, I will get PHYSTATUS, that validates the value on RXSTATUS
> lines.
>
> But than, in table 5-14 (page 111) I find out that TXELECIDLE
> also must be asserted to initiate Receiver Detection.
>
> And again, in other parts of the document, I find that when
> changing powermode, I need to wait for PHYSTATUS to indicate
> that power mode has been changed (change completed).
>
> I have tried the original description as on page 151, as well,
> as adding the other bits I found out. And still, I consistently
> get "No Receiver Detected".
>
> The other side has no problem detecting my hardware.
>
> Is there somebody who knows this stuff inside out and can
> shed some light on how to make this work ?
>
> Thanks,
> rudi


I am curious. Has anybody out there actually used the Remote
Receiver detect function ? Am I the only one ?

Thanks,
rudi
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