Intel® Arria® 10 Avalon® Streaming with SR-IOV IP for PCIe* User Guide

ID 683686
Date 1/11/2022
Document Table of Contents

9.1. PCI Express Protocol Stack

The Intel® Arria® 10 Hard IP for PCI Express with SR-IOV implements the complete PCI Express protocol stack as defined in the PCI Express Base Specification. The protocol stack includes the following layers:

  • Transaction Layer—The Transaction Layer contains the Configuration Space, which manages communication with the Application Layer, the RX and TX channels, the RX buffer, and flow control credits.
  • Data Link Layer—The Data Link Layer, located between the Physical Layer and the Transaction Layer, manages packet transmission and maintains data integrity at the link level. Specifically, the Data Link Layer performs the following tasks:
    • Manages transmission and reception of Data Link Layer Packets (DLLPs)
    • Generates all transmission cyclical redundancy code (CRC) values and checks all CRCs during reception
    • Manages the retry buffer and retry mechanism according to received ACK/NAK Data Link Layer packets
    • Initializes the flow control mechanism for DLLPs and routes flow control credits to and from the Transaction Layer
  • Physical Layer—The Physical Layer initializes the speed, lane numbering, and lane width of the PCI Express link according to packets received from the link and directives received from higher layers.

The following figure provides a high‑level block diagram.

Figure 51.  Intel® Arria® 10 Hard IP for PCI Express with SR-IOV
Table 99.  Application Layer Clock Frequencies








125 MHz @ 256 bits



125 MHz @ 256 bits

250 MHz @ 256 bits