Arria® 10 and Cyclone® 10 GX Avalon® Memory-Mapped (Avalon-MM) Interface for PCI Express* User Guide

ID 683724
Date 9/10/2024
Public
Document Table of Contents

5. 64- or 128-Bit Avalon-MM Interface to the Endpoint Application Layer

The Arria® 10 or Cyclone® 10 GX Hard IP for PCI Express with an Avalon-MM interface to the Application Layer includes an Avalon-MM bridge. This bridge translates PCI Express TLPs to standard Avalon-MM read and write commands, and vice versa. Consequently, you do not need a detailed understanding of the PCI Express TLPs to use this Avalon-MM variant.

The Avalon® -MM Arria® 10 Hard IP for PCI Express* communicates with the Application Layer in the FPGA core fabric via the following interfaces:

  • RX Master (RXM): This is a bursting RX Avalon® -MM master interface that translates Memory Read and Write TLPs from the PCIe* domain to Avalon® -MM reads and writes and sends them to the slave in the Avalon® -MM memory space.
  • TX Slave (TXS): This is a bursting TX Avalon® -MM slave interface that translates memory-mapped reads and writes from the Avalon® -MM domain to PCIe* Memory Read and Write TLPs and sends them to the PCIe* memory space.
  • Control Register Access (CRA): This optional Avalon® -MM slave interface allows the Application Layer logic to access the internal control and status registers of the IP core.
  • Hard IP Reconfiguration: This optional interface allows the Application Layer logic to dynamically modify the contents of the IP core's configuration registers that are read-only at run time.
  • Hard IP Status: This optional interface contains status signals for the Hard IP to facilitate the debugging process.
  • MSI/MSI-X: These interfaces provide the necessary information for the Application Layer logic to construct and send Message Signaled Interrupts to the host.
Note: The PIPE interface is used to communicate with the PHY Layer and not the Application Layer.
Figure 27. Signals in 64- or 128-Bit Avalon-MM Interface to the Application Layer

Variations using the Avalon-MM interface implement the Avalon-MM protocol described in the Avalon Interface Specifications. Refer to this specification for information about the Avalon-MM protocol, including timing diagrams.