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

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ID 683268
Date 7/14/2021
Public
Document Table of Contents
Document Table of Contents x
1. About the P-tile Avalon® Intel® FPGA IPs for PCI Express 2. IP Architecture and Functional Description 3. Parameters 4. Interfaces 5. Advanced Features 6. Troubleshooting/Debugging 7. Document Revision History for the P-tile Avalon® Memory-mapped Intel FPGA IP for PCI Express User Guide A. Configuration Space Registers
1. About the P-tile Avalon® Intel® FPGA IPs for PCI Express x
1.1. Overview 1.2. Features 1.3. Release Information 1.4. Device Family Support 1.5. Performance and Resource Utilization 1.6. IP Core and Design Example Support Levels
2. IP Architecture and Functional Description x
2.1. Top-Level Architecture 2.2. Functional Description
2.1. Top-Level Architecture x
2.1.1. Avalon® -MM Bridge Architecture 2.1.2. Clock Domains 2.1.3. Refclk 2.1.4. Reset
2.2. Functional Description x
2.2.1. PMA/PCS 2.2.2. Data Link Layer Overview 2.2.3. Transaction Layer Overview 2.2.4. Avalon® -MM Bridge
2.2.4. Avalon® -MM Bridge x
2.2.4.1. Endpoint Mode with Data Movers 2.2.4.2. Endpoint Mode 2.2.4.3. Root Port Mode
3. Parameters x
3.1. Top-Level Settings 3.2. Core Parameters 3.3. Avalon-MM Settings
3.2. Core Parameters x
3.2.1. Base Address Registers 3.2.2. PCI Express and PCI Capabilities Parameters 3.2.3. Device Identification Registers 3.2.4. Configuration, Debug and Extension Options
3.2.2. PCI Express and PCI Capabilities Parameters x
3.2.2.1. Device Capabilities 3.2.2.2. Link Capabilities 3.2.2.3. Legacy Interrupt Pin Register 3.2.2.4. MSI Capabilities 3.2.2.5. MSI-X Capabilities 3.2.2.6. Device Serial Number Capability 3.2.2.7. TLP Processing Hints (TPH)
4. Interfaces x
4.1. Overview 4.2. Clocks and Resets 4.3. Avalon® -MM Interface 4.4. Serial Data Interface 4.5. Hard IP Status Interface 4.6. Interrupt Interface 4.7. Hot Plug Interface (RP Only) 4.8. Power Management Interface 4.9. Configuration Output Interface 4.10. Hard IP Reconfiguration Interface 4.11. PHY Reconfiguration Interface
4.2. Clocks and Resets x
4.2.1. Interface Clock Signals 4.2.2. Interface Reset Signals
4.3. Avalon® -MM Interface x
4.3.1. Endpoint Mode Interface (512-bit Avalon® -MM Interface) 4.3.2. Root Port Mode Interface (256-bit Avalon® -MM Interface)
4.3.1. Endpoint Mode Interface (512-bit Avalon® -MM Interface) x
4.3.1.1. Bursting Avalon® -MM Master and Conduit 4.3.1.2. Bursting Avalon® -MM Slave and Conduit 4.3.1.3. Read Data Mover 4.3.1.4. Write Data Mover 4.3.1.5. Descriptor Format for Data Movers 4.3.1.6. Avalon® -MM DMA Operations
4.3.1.1. Bursting Avalon® -MM Master and Conduit x
4.3.1.1.1. Bursting Avalon® -MM Master and Conduit in Non-Bursting Mode
4.3.1.2. Bursting Avalon® -MM Slave and Conduit x
4.3.1.2.1. Bursting Avalon® -MM Slave and Conduit in Non-Bursting Mode
4.3.1.3. Read Data Mover x
4.3.1.3.1. Read Data Mover Avalon® -MM Write Master and Conduit 4.3.1.3.2. Read Data Mover Avalon® -ST Descriptor Sinks 4.3.1.3.3. Read Data Mover Status Avalon® -ST Source
4.3.1.4. Write Data Mover x
4.3.1.4.1. Write Data Mover Avalon® -MM Read Master and Conduit 4.3.1.4.2. Write Data Mover Avalon® -ST Descriptor Sinks 4.3.1.4.3. Write Data Mover Status Avalon® -ST Source
4.3.2. Root Port Mode Interface (256-bit Avalon® -MM Interface) x
4.3.2.1. High Performance Avalon® -MM Slave (HPTXS) Interface 4.3.2.2. High Performance Avalon® -MM Master (HPRXM) Interface 4.3.2.3. 32-Bit Control Register Access (CRA) Slave (Root Port only)
4.6. Interrupt Interface x
4.6.1. Legacy Interrupts 4.6.2. MSI 4.6.3. MSI-X
4.6.3. MSI-X x
4.6.3.1. Implementing MSI-X Interrupts
4.10. Hard IP Reconfiguration Interface x
4.10.1. Address Map for the User Avalon-MM Interface 4.10.2. Configuration Registers Access
4.10.2. Configuration Registers Access x
4.10.2.1. Using Direct User Avalon-MM Interface (Byte Access) 4.10.2.2. Using the Debug Register Interface Access
5. Advanced Features x
5.1. PCIe* Port Bifurcation and PHY Channel Mapping
6. Troubleshooting/Debugging x
6.1. Hardware 6.2. Debug Toolkit
6.1. Hardware x
6.1.1. Debugging Link Training Issues 6.1.2. Debugging Data Transfer and Performance Issues
6.1.1. Debugging Link Training Issues x
6.1.1.1. Generic Tools and Utilities 6.1.1.2. SignalTapII Logic Analyzer 6.1.1.3. Additional Debug Tools
6.1.2. Debugging Data Transfer and Performance Issues x
6.1.2.1. Advanced Error Reporting (AER) 6.1.2.2. Second-Level Debug Tools
6.2. Debug Toolkit x
6.2.1. Overview 6.2.2. Enabling the P-Tile Debug Toolkit 6.2.3. Launching the P-Tile Debug Toolkit 6.2.4. Using the P-Tile Debug Toolkit 6.2.5. Enabling the P-Tile Link Inspector 6.2.6. Using the P-Tile Link Inspector
A. Configuration Space Registers x
A.1. Configuration Space Registers A.2. Intel-Defined VSEC Capability Registers
A.1. Configuration Space Registers x
A.1.1. Register Access Definitions A.1.2. PCIe Configuration Header Registers A.1.3. PCI Express Capability Structures A.1.4. Physical Layer 16.0 GT/s Extended Capability Structure A.1.5. MSI-X Registers
A.2. Intel-Defined VSEC Capability Registers x
A.2.1. Intel-Defined VSEC Capability Header (Offset 00h) A.2.2. Intel-Defined Vendor Specific Header (Offset 04h) A.2.3. Intel Marker (Offset 08h) A.2.4. JTAG Silicon ID (Offset 0x0C - 0x18) A.2.5. User Configurable Device and Board ID (Offset 0x1C - 0x1D) A.2.6. General Purpose Control and Status Register (Offset 0x30) A.2.7. Uncorrectable Internal Error Status Register (Offset 0x34) A.2.8. Uncorrectable Internal Error Mask Register (Offset 0x38) A.2.9. Correctable Internal Error Status Register (Offset 0x3C) A.2.10. Correctable Internal Error Mask Register (Offset 0x40)
1. About the P-tile Avalon® Intel® FPGA IPs for PCI Express
2. IP Architecture and Functional Description
3. Parameters
4. Interfaces
5. Advanced Features
6. Troubleshooting/Debugging
7. Document Revision History for the P-tile Avalon® Memory-mapped Intel FPGA IP for PCI Express User Guide
A. Configuration Space Registers

2.2.2. Data Link Layer Overview

The Data Link Layer (DLL) is located between the Transaction Layer and the Physical Layer. It maintains packet integrity and communicates (by DLL packet transmission) at the PCI Express link level.

The DLL implements the following functions:

  • Link management through the reception and transmission of DLL Packets (DLLP), which are used for the following functions:
    • Power management of DLLP reception and transmission
    • To transmit and receive ACK/NAK packets
    • Data integrity through the generation and checking of CRCs for TLPs and DLLPs
    • TLP retransmission in case of NAK DLLP reception or replay timeout, using the retry (replay) buffer
    • Management of the retry buffer
    • Link retraining requests in case of error through the Link Training and Status State Machine (LTSSM) of the Physical Layer
Figure 7. Data Link Layer

The DLL has the following sub-blocks:

  • Data Link Control and Management State Machine—This state machine connects to both the Physical Layer’s LTSSM state machine and the Transaction Layer. It initializes the link and flow control credits and reports status to the Transaction Layer.
  • Power Management—This function handles the handshake to enter low power mode. Such a transition is based on register values in the Configuration Space and received Power Management (PM) DLLPs. For more details on the power states supported by the P-Tile Avalon® -MM IP for PCIe, refer to section Power Management Interface.
  • Data Link Layer Packet Generator and Checker—This block is associated with the DLLP’s 16-bit CRC and maintains the integrity of transmitted packets.
  • Transaction Layer Packet Generator—This block generates transmit packets, including a sequence number and a 32-bit Link CRC (LCRC). The packets are also sent to the retry buffer for internal storage. In retry mode, the TLP generator receives the packets from the retry buffer and generates the CRC for the transmit packet.
  • Retry Buffer—The retry buffer stores TLPs and retransmits all unacknowledged packets in the case of NAK DLLP reception. In case of ACK DLLP reception, the retry buffer discards all acknowledged packets.
  • ACK/NAK Packets—The ACK/NAK block handles ACK/NAK DLLPs and generates the sequence number of transmitted packets.
  • Transaction Layer Packet Checker—This block checks the integrity of the received TLP and generates a request for transmission of an ACK/NAK DLLP.
  • TX Arbitration—This block arbitrates transactions, prioritizing in the following order:
    • Initialize FC Data Link Layer packet
    • ACK/NAK DLLP (high priority)
    • Update FC DLLP (high priority)
    • PM DLLP
    • Retry buffer TLP
    • TLP
    • Update FC DLLP (low priority)
    • ACK/NAK FC DLLP (low priority)
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