PCIe to PCI bridge

Avinash H

Other Parts Discussed in Thread: XIO2001

Hi All,

I'm planning XIO2001 PCIe to PCI bridge to interface four identical PCI devices.

The PCI devices are to be interfaced directly to bridge. ie. I'll not use Slot connectors as this will be one of the custom design board.

But the PCI devices does not have BUS_REQ and BUS_GNT pins since all four devices are same.

I have to use Forward bridge mode with Internal arbiter configuration for XIO2001.

I'm planning to give AD16 to AD19 lines for IDSEL pin for each PCI device.

Now my doubt is if I don't use REQ or GNT pins of the bridge in the design, my design will work or not? The PCI devices will get detected or not.

Also How INT pins have to be configured for each PCI device? The PCI devices have only INTA pin. Hence INTA pin of XIO2001 has to be tied to all four devices or INTA, INTB, INTC, INTD for each device?

Fyi our system will be based on Linux OS.

Looking for your valuable suggestions.

Thanks in advance

Avinash H

over 9 years ago

Clemens Ladisch over 9 years ago

Guru 317870 points

In theory, the REQ/GNT signals are an integral part of the PCI bus interface. Are your devices bus master capable? (What specific device are you using?)

According to table 2-13 of the PCI Express Base Specification, Rev. 1.1, for device numbers 0 to 4, the INTA pins must be connected to the bridge's INTA, INTB, INTC, INTD.

Avinash H over 9 years ago in reply to Clemens Ladisch

Prodigy 20 points

Hello Clemens, Thanks for your reply.

Yes, the devices are Master capable.

They are communication protocol converters from PCI to Serial conversion.

Clemens Ladisch over 9 years ago in reply to Avinash H

Guru 317870 points

A bus master device must have REQ/GNT pins.

What specific chip are you using?

Interface

Interface forum

PCIe to PCI bridge