Oh yes, always design to the spec. - even if others don't!

I used to do a lot of VMEbus circuit design, and on a few occasions I'd get
called in to debug a customer's system which "worked fine until we put your
board in".  In all cases, one of the customer's boards was found to be
non-compliant but had worked OK with a lower spec. processor board - they'd
designed circuitry that didn't meet the spec but worked when originally
tested.

Looks like it's the same with PCI - shortcuts can work fine in some systems
but not the higher speed ones.

Regards

Andy Gulliver

> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
> Sent: 27 March 2001 13:44
> To: Protel EDA Forum
> Subject: Re: [PEDA] Info about PCI specs
>
>
> Yea, most of the cheap cards I see are not PCI compliant. We have
> a cheap vid
> card that works OK in 32/33 but in a 66Mhz slot it gets a bit
> weird...even
> though the PCI interface is rated for 66Mhz.
>
> If you've ever looked the PCI clock and signals on an active slot
> you'll see
> why the spec is important. Reflected-wave switching requires careful
> consideration of the loads placed in the circuit.
>
> I've designed quite a few PCI cards and can tell you that the PCI
> spec is a
> handy thing to have. Also, having your own PCI vendor ID is
> convenient for
> custom FPGA stuff.For instance, our crypto card is recognized and
> configured
> automatically by the OpenBSD kernel.
>

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* To post a message: mailto:[EMAIL PROTECTED]
*
* To join or leave this list visit:
* http://www.techservinc.com/protelusers/subscrib.html
*                      - or email -
* mailto:[EMAIL PROTECTED]?body=leave%20proteledaforum
*
* Contact the list manager:
* mailto:[EMAIL PROTECTED]
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Reply via email to