FPGA configuration time for PCI identification ?

Jan 10, 2006 8 Replies

It's in the PCI spec. It's 2^25 clock cycles if memory serves me right.

Petter

-- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail?

Hello,



We have a 2VP40 ( 15.5Mbits configuration ) to configure through a 8 bits



90ns flash by a CPLD. I try to find what time has the PCI IP to respond to PCI boot board identification process before been ignored ? This will give the time I have to configure my FPGA.

Does someone has information on this allowed time ?



Thanks.



Stéphane.


Petter,

I had read somewhere 80ms was all the time you had before the PCI bus was definitely allowed to ignore you (forever).

2^25 clocks is considerably longer than this. Even at 133 MHz.

Aust> "sjulhes" writes:

For PCI 2.3, and revision 1.0a of the PCI-X spec:

100 ms from power valid to RST# high.

For PCI 2^25 clocks from RST# high to first configuration access.

For PCI-X 2^26 clocks from RST# high to first configuration access.

Regards,

John McCaskill

Thank you veru much.

Stéphane.

"John McCaskill" a écrit dans le message de news: snipped-for-privacy@f14g2000cwb.googlegroups.com...

sjulhes wrote:

For PCI 2.3, and revision 1.0a of the PCI-X spec:

100 ms from power valid to RST# high.

For PCI 2^25 clocks from RST# high to first configuration access.

For PCI-X 2^26 clocks from RST# high to first configuration access.

Regards,

John McCaskill

I just can't find it in the spec ! Can someone give me the right section ?

thanks.

Stéphane.

"John McCaskill" a écrit dans le message de news: snipped-for-privacy@f14g2000cwb.googlegroups.com...

sjulhes wrote:

For PCI 2.3, and revision 1.0a of the PCI-X spec:

100 ms from power valid to RST# high.

For PCI 2^25 clocks from RST# high to first configuration access.

For PCI-X 2^26 clocks from RST# high to first configuration access.

Regards,

John McCaskill

Ok, I found it !

But what about the PCI express ? I don't have the spec so if someone can tell me if there is the same process and what is the allowed time ?

thank you

stéphane.

"John McCaskill" a écrit dans le message de news: snipped-for-privacy@f14g2000cwb.googlegroups.com...

sjulhes wrote:

For PCI 2.3, and revision 1.0a of the PCI-X spec:

100 ms from power valid to RST# high.

For PCI 2^25 clocks from RST# high to first configuration access.

For PCI-X 2^26 clocks from RST# high to first configuration access.

Regards,

John McCaskill

sjulhes schrieb:

PCIe is hot plug capable, so it probably does not matter. Just tell the system that your device is present when you finished configuration.

Kolja Sulimma

As I read the PCIe specification, it seems that the hot plug capability is optional on the system board, so this may not always work. The timing of PERST# is minimum 100ms after power stable and 100us after REFCLK stable.

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