RapidIO Intel FPGA IP User Guide

ID 683884
Date 9/15/2021
Public
Document Table of Contents

3.2.1. Transport Layer

Enable 16-Bit Device ID Width

All RapidIO IP core variations have a Transport layer. The Transport Layer parameters determine whether the RapidIO IP core uses 8-bit or 16-bit device IDs, whether the Transport layer has an Avalon® -ST pass-through interface, and whether the IP core is in promiscuous mode.

The Enable 16-bit device ID width setting specifies whether the IP core supports an 8-bit device ID width or a 16-bit device ID width. RapidIO packets contain destination ID and source ID fields, which have the specified width. If this IP core uses 16-bit device IDs, it supports large common transport systems.

Enable Avalon® -ST Pass-Through Interface

Turn on Enable Avalon® -ST pass-through interface to include the Avalon® -ST pass-through interface in your RapidIO variation.

The Transport layer routes all unrecognized packets to the Avalon® -ST pass-through interface. Unrecognized packets are those that contain Format Types (ftypes) for Logical layers not enabled in this IP core, or destination IDs not assigned to this endpoint. However, if you disable destination ID checking, the packet is a request packet with a supported ftype, and the Transport Type (tt) field of the packet matches the device ID width setting of this IP core, the packet is routed to the appropriate Logical layer.

Note: The destination ID can match this endpoint only if the tt field in the packet matches the device ID width setting of the endpoint.

Request packets with a supported ftype and correct tt field, but an unsupported ttype, are routed to the Logical layer supporting the ftype, which allows the following tasks:

  • An ERROR response can be sent to requests that require a response.
  • An unsupported_transaction error can be recorded in the Error Management extension registers.

Response packets are routed to a Logical layer module or the Avalon® -ST pass-through port based on the value of the target transaction ID field.

Destination ID Checking

Disable Destination ID checking by default lets you turn on or off the option to route a request packet with a supported ftype but a destination ID not assigned to this endpoint. The effect of this settings is detailed in the above section.

You specify the initial value for the option in the RapidIO parameter editor, and software can change it by modifying the value of the PROMISCUOUS_MODE bit in the Rx Transport Control register.

This parameter is not available for variations that target Intel® Arria® 10 and Intel® Cyclone® 10 GX devices. RapidIO IP core Intel® Arria® 10 and Intel® Cyclone® 10 GX variations do not check destination IDs by default. However, you can modify the PROMISCUOUS_MODE setting during normal operation.