V-Series Avalon-MM DMA Interface for PCIe Solutions User Guide

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ID 683514
Date 7/31/2018
Public
Document Table of Contents
Document Table of Contents x
1. Datasheet 2. Getting Started with the Avalon-MM DMA 3. Parameter Settings 4. Registers 5. Error Handling 6. PCI Express Protocol Stack 7. V-Series Avalon-MM DMA for PCI Express 8. Transceiver PHY IP Reconfiguration A. Frequently Asked Questions for V-Series Avalon-MM DMA Interface for PCIe B. V-Series Interface for PCIe Solutions User Guide Archive C. Document Revision History
1. Datasheet x
1.1. V-Series Avalon-MM DMA Interface for PCIe* Datasheet 1.2. Features 1.3. Comparison of Avalon-ST, Avalon-MM and Avalon-MM with DMA Interfaces for V-Series Devices 1.4. Release Information 1.5. V-Series Device Family Support 1.6. Design Examples 1.7. Debug Features 1.8. IP Core Verification 1.9. Resource Utilization 1.10. V-Series Recommended Speed Grades 1.11. Creating a Design for PCI Express
1.8. IP Core Verification x
1.8.1. Compatibility Testing Environment
2. Getting Started with the Avalon-MM DMA x
2.1. Understanding the Avalon-MM DMA Ports 2.2. Generating the Testbench 2.3. Simulating the Example Design in ModelSim* 2.4. Running a Gate-Level Simulation 2.5. Generating Synthesis Files 2.6. Compiling the Design 2.7. Creating a Quartus® Prime Project
2.2. Generating the Testbench x
2.2.1. Understanding the Simulation Generated Files 2.2.2. Understanding Simulation Log File Generation
3. Parameter Settings x
3.1. System Settings 3.2. Base Address Register (BAR) Settings 3.3. Device Identification Registers 3.4. PCI Express and PCI Capabilities Parameters 3.5. PCIe Address Space Settings
3.4. PCI Express and PCI Capabilities Parameters x
3.4.1. Device Capabilities 3.4.2. Error Reporting 3.4.3. Link Capabilities 3.4.4. MSI and MSI-X Capabilities 3.4.5. Power Management
4. Registers x
4.1. Correspondence between Configuration Space Registers and the PCIe Specification 4.2. Type 0 Configuration Space Registers 4.3. Type 1 Configuration Space Registers 4.4. PCI Express Capability Structures 4.5. Intel-Defined VSEC Registers 4.6. Advanced Error Reporting Capability 4.7. DMA Descriptor Controller Registers 4.8. Control Register Access (CRA) Avalon-MM Slave Port
4.5. Intel-Defined VSEC Registers x
4.5.1. CvP Registers
4.6. Advanced Error Reporting Capability x
4.6.1. Uncorrectable Internal Error Mask Register 4.6.2. Uncorrectable Internal Error Status Register 4.6.3. Correctable Internal Error Mask Register 4.6.4. Correctable Internal Error Status Register
4.7. DMA Descriptor Controller Registers x
4.7.1. Read DMA Descriptor Controller Registers 4.7.2. Write DMA Descriptor Controller Registers 4.7.3. Read DMA and Write DMA Descriptor Format 4.7.4. Read DMA Example 4.7.5. Software Program for Simultaneous Read and Write DMA
5. Error Handling x
5.1. Physical Layer Errors 5.2. Data Link Layer Errors 5.3. Transaction Layer Errors 5.4. Error Reporting and Data Poisoning 5.5. Uncorrectable and Correctable Error Status Bits
6. PCI Express Protocol Stack x
6.1. Top-Level Interfaces 6.2. Data Link Layer 6.3. Physical Layer
6.1. Top-Level Interfaces x
6.1.1. Avalon-MM DMA Interface 6.1.2. Clocks and Reset 6.1.3. Transceiver Reconfiguration 6.1.4. Interrupts 6.1.5. PIPE
7. V-Series Avalon-MM DMA for PCI Express x
7.1. Understanding the Internal DMA Descriptor Controller 7.2. Understanding the External DMA Descriptor Controller
8. Transceiver PHY IP Reconfiguration x
8.1. Connecting the Transceiver Reconfiguration Controller IP Core 8.2. Transceiver Reconfiguration Controller Connectivity for Designs Using CvP
C. Document Revision History x
C.1. Document Revision History for the V-Series Avalon® Memory Mapped (Avalon-MM) DMA Interface for PCIe* Solutions User Guide
1. Datasheet
2. Getting Started with the Avalon-MM DMA
3. Parameter Settings
4. Registers
5. Error Handling
6. PCI Express Protocol Stack
7. V-Series Avalon-MM DMA for PCI Express
8. Transceiver PHY IP Reconfiguration
A. Frequently Asked Questions for V-Series Avalon-MM DMA Interface for PCIe
B. V-Series Interface for PCIe Solutions User Guide Archive
C. Document Revision History

6.2. Data Link Layer

The Data Link Layer 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 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 14. 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. All of the V-Series Hard IP for PCIe IP core variants do not support low power modes.
  • 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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