P-Tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide

ID 683059
Date 10/07/2024
Public
Document Table of Contents

3.3.1. Overview

When the TLP Bypass feature is enabled, the P-Tile Avalon® -ST IP does not process received TLPs internally but outputs them to the user application. This allows the application to implement a custom Transaction Layer.

Note that in TLP Bypass mode, the PCIe Hard IP does not generate/check the ECRC and will not remove it if the received TLP has the ECRC.

The P-tile Avalon® -ST IP in TLP Bypass mode still includes some of the PCIe configuration space registers related to link operation (refer to the Configuration Space Registers chapter for the list of registers).

P-Tile interfaces with the application logic via the Avalon® -ST interface (for all TLP traffic), the User Avalon® -MM interface (for Lite TL’s configuration registers access) and other miscellaneous signals.
Note: Enabling the TLP Bypass mode and the independent PERST in any IP mode restricts the access to the following registers: pn_app_err_info_i[13], pn_app_err_valid_i[1], and pn_app_err_hdr_i[32].
Note: In 4x4 mode, the pn prefix in the signal names stands for p0, p1, p2, and p3 for the four x4 ports.
Figure 12. P-Tile Avalon® -ST IP in TLP Bypass Mode

In TLP bypass mode, P-Tile supports the autonomous Hard IP feature. It responds to configuration accesses before the FPGA fabric enters user mode with Completions with a CRS code.

However, in TLP bypass mode, CvP init and update are not supported.