AXI Streaming Intel® FPGA IP for PCI Express* User Guide

ID 790711
Date 2/12/2024
Public

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Document Table of Contents

6.1. Overview

You can determine each of the interface sections from the prefixes in the signal names.

  • p0: x16 core
  • p1: x8 core
  • p2: x4 core
  • p3: x4 core

The AXI Streaming Intel® FPGA IP for PCI Express* Top-Level Signals figure below shows the top-level signals of this IP. Note that the signal names in the figure will get the appropriate prefix p<n> (where n = 0, 1, 2, 3) depending on which of the supported configurations (1x16, 2x8 or 4x4) the IP is in.

As an example, the ss_app_st_rx_tdata bus can take on the following names:

  • In the 1x16 configuration, only the x16 core is active. For Gen5x16, this bus appears as p0_ss_app_st_rx_tdata [1023:0].
  • In the 2x8 configuration, both the x16 core and x8 core are active. In this case, this bus is split into p0_ss_app_st_rx_tdata[511:0] and p1_ss_app_st_rx_tdata [511:0] in Gen5.

The only cases where the interface signal names do not get the pn prefixes are the interfaces that are common for all the cores, like the PHY reconfiguration interface, clocks and resets. For example, there is only one xcvr_reconfig_clk that is shared by all the cores.

You can enable the PHY reconfiguration interface from the PCIe* Interface Settings in the Parameter editor.

Each of the cores has its own AXI-ST interface to the user logic. The number of IP-to-User Logic interfaces exposed to the FPGA fabric are different based on the configuration modes.

For a summary of the IP to FPGA fabric interfaces, refer to Application Packet Interface.

Figure 27.  AXI Streaming Intel® FPGA IP for PCI Express* Top-Level Signals

The following table shows the values of the variable n that is used to define the bus indices for top-level signal busses shown in the top-level block diagram above. The value of this variable changes depending on which configuration is active (1x16, 1x8, 2x8).

Table 24.  Variable Used in the Bus Indices
Variable 1 x16 configuration 1 x8 configuration 2 x8 configuration
n 1 1 2
b 16 8 16