Difference between PCIE IP "Configuration Space Bypass" for Arria 10 and "TLP Bypass" for Stratix 10

[lcy2000]

Hi,

Thank you for viewing this thread.

Currently I'm doing a tech selection for a custom PCIe switch. Both Arria 10 and Stratix 10 meets my requirements in terms of number of XCVRs, PCIe hard cores and logic resources.

But after reading "Avalon-ST PCIe IP" documents for both, I saw a little difference where Arria 10 claims that it features "Configuration Space Bypass" but Stratix 10 features "TLP Bypass".

So my question is that:

1. What's the difference between "Configuration Space Bypass" and "TLP Bypass"?
2. Do they provide equivalent capability to RX and TX all the valid TLP packets over the link?

Thank you very much

[skbeh]

Hi Chenyang Li

When the configuration space bypass mode is enabled, users coded their own sets of PCIe configuration registers (including the PCIe Express Capability and Secondary PCI Expess Extended Capability registers). It drives TLPs to the custom Configuration Space. 

The IP will bypass the Transaction Layer Configuration Space registers included as

part of the Hard IP, allowing users to substitute a custom Configuration Space implemented in soft logic.

In TLP Bypass mode, all the TLP including the configuration TLP will be exposed to user logic through avst interface, customer can implement the user logics.

Both can pass all well‑formed TLPs to the Application Layer using the Avalon-ST RX interface.

[lcy2000]

Thank you for answering my thread @skbeh.

I'm a little confused. So is there any limitation regarding PCIe for Arria 10 than Stratix 10?
As I see, it seems like TLP Bypass is an acronym to configuration space bypass.

Thank you very much.

[skbeh · Accepted solution]

Hi Chenyang Li

I agreed that TLP Bypass(S10) is an acronym to configuration space bypass (A10).

It allows the implementation of advanced features such as:

- The upstream port or the downstream port of a switch.

- A custom implementation of a Transaction Layer to meet specific user requirements.