XIO3130: Daisy-chain connection of PCIe Packet Switch

g.f.

Part Number: XIO3130

Hi,

I have a question about XIO3130 PCIe packet switch.

In our system, there are one Master board and eight independent sub board.
We are planning to connect the master board and each sub board via PCIe.
So, we are searching for packet switch which can fanout 8 outputs.

It seems XIO3130 is the only packet switch product in TI,
and XIO3130 only support 3 fanout.
Is it possible to realize 8 fanout by using a few XIO3130?
For example connecting a few XIO3130 by daisy-chain connection.

best regards,
g.f.

over 7 years ago

0 Roberto Diaz over 7 years ago

TI__Genius 11255 points

Hello,

Yes, you can daisy-chain some XIO3130 to generate it.

Regards,
Roberto

0 g.f. over 7 years ago in reply to Roberto Diaz

Guru 15520 points

Hi Roberto,

Thank you for the reply and I understood that using multiple XIO3130 can realize 8 fanout.
I would like to ask how to connect the multiple XIO3130.
Please see the attached powerpoint file. I wrote connection example and have a few questions.

If connecting the multiple XIO3130 as like attached file, who can configure the XIO3130 internal registers and external EEPROM?
And how to configure it?

I understood that if using single XIO3130, configuration of XIO3130 will be done via upstream device(PCIe root complex).
But I don't know how to configure it if XIO3130 are connected by daisy-chain.

best regards,
g.f.

XIO3130_Daisy Chain connection.pptx

0 Clemens Ladisch over 7 years ago in reply to g.f.

Guru 317370 points

The initialization is done by the OS, and having multiple switches should not make any difference.

The EEPROM is optional. Do you actually need to change any register to a non-default value?

0 Roberto Diaz over 7 years ago in reply to Clemens Ladisch

TI__Genius 11255 points

Hello GF,

As Clemens commented, you only will need a EEPROM if yo want to change the default register values, so if you are not changing them you will not need the EEPROMs

Regards, Roberto

0 g.f. over 7 years ago in reply to Roberto Diaz

Guru 15520 points

Hi Clemens and Roberto,

Thank you for the reply.
I understood that EEPROM is optional.
By the way, is using the default register value usual for XIO3130?

And I have one more question to ask.
How many XIO3130 can be connected by daisy-chain?
Are there the number of limitation?
Please take a look at atttached file.
We are planning to connect Main board and each Sub board via PCIe by using XIO3130.

best regards,
g.f.

XIO3130_Daisy Chain connection_part2.pptx

0 g.f. over 7 years ago in reply to Roberto Diaz

Guru 15520 points

Hi Roberto,

I would like to have the anwser for my last questions(posted Oct 11th, 2017).
I'm sorry for disturbing you, but please gave me a feedback.

best regards,
g.f.

0 Clemens Ladisch over 7 years ago in reply to g.f.

Guru 317370 points

There is no electrical limit on the length of the chain, and the PCI Express specification defines the bus number as an eight-bit field, i.e., for 256 buses.

However, the host hardware or operating system might put a limit on the bus numbers, or on the number of buses handled by a single root port. In other words, the XIO3130 has no limit, but your main board might have one.

0 g.f. over 7 years ago in reply to Clemens Ladisch

Guru 15520 points

Hi Clemens,

Thank you for the reply.
I understood.

best regards,
g.f.

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XIO3130: Daisy-chain connection of PCIe Packet Switch