From: John Sigler <linux.kernel@free.fr>
To: linux-kernel@vger.kernel.org, linux-pci@atrey.karlin.mff.cuni.cz
Subject: Is the PCI clock within the spec?
Date: Tue, 04 Dec 2007 11:57:43 +0100 [thread overview]
Message-ID: <475532A7.1000408@free.fr> (raw)
Hello everyone,
I have an x86 system, running Linux 2.6.22.1-rt9, in which I plug one
or two PCI I/O boards. I had been experiencing complete system lock-ups
until I sent the system to the board manufacturer, and he fixed the
problem. However, he told me that the PCI clock seemed out of spec,
as far as voltage is concerned.
(Disclaimer: my knowledge of PCI is 0.)
The board manufacturer sent me the plot of (what appears to be) voltage
versus time for the PCI clock.
http://linux.kernel.free.fr/plot1.jpg
The system manufacturer sent me a similar plot.
http://linux.kernel.free.fr/plot2.jpg
As far as my understanding goes, the signal should alternate between
0 V and 3.3 V (??). In the second plot, it looks like Vmax ~ 4.6V
and Vmin ~ -1.4V (Pk-Pk(C1)=6.08V might mean peak-to-peak voltage?)
0) What is this C1 both plots mention?
1) Am I reading the plot correctly?
2) Is -1.4V in DC even possible?
3) 4.6V is 1.3V above 3.3V and -1.4V is -1.4V below 0. (Assuming I read
the numbers correctly) Are these values within the PCI spec? Or are
these voltages dangerous and / or might cause some problems with some
PCI boards?
Regards.
next reply other threads:[~2007-12-04 10:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-04 10:57 John Sigler [this message]
2007-12-04 12:42 ` Is the PCI clock within the spec? Sébastien Dugué
2007-12-04 13:27 ` John Sigler
2007-12-04 13:48 ` linux-os (Dick Johnson)
2007-12-04 15:12 ` John Sigler
2007-12-04 15:51 ` linux-os (Dick Johnson)
2007-12-04 21:37 ` David Schwartz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=475532A7.1000408@free.fr \
--to=linux.kernel@free.fr \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@atrey.karlin.mff.cuni.cz \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).