R-tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide

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ID 683501
Date 12/13/2021
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Document Table of Contents
Document Table of Contents x
1. Introduction 2. IP Architecture and Functional Description 3. Advanced Features 4. Interfaces 5. Parameters 6. R-tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide Archives 7. Document Revision History for the R-tile Avalon® Streaming Intel FPGA IP for PCI Express User Guide A. Configuration Space Registers B. Root Port Enumeration C. Implementation of Address Translation Services (ATS) in Endpoint Mode D. Packets Forwarded to the User Application in TLP Bypass Mode
1. Introduction 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 Support Levels
1.1. Overview x
1.1.1. Standards and Specifications Compliance
2. IP Architecture and Functional Description x
2.1. Overview 2.2. Bias Temperature Instability (BTI) Protection Mode 2.3. PCIe Hard IP Mode 2.4. PIPE Direct Mode
2.3. PCIe Hard IP Mode x
2.3.1. Clocking 2.3.2. Reset 2.3.3. PCI Express Protocol Stack
2.3.3. PCI Express Protocol Stack x
2.3.3.1. PMA/PCS 2.3.3.2. Data Link Layer Overview 2.3.3.3. Transaction Layer Overview
2.4. PIPE Direct Mode x
2.4.1. Clocking 2.4.2. Reset 2.4.3. PIPE Layer
3. Advanced Features x
3.1. PCIe Port Bifurcation and PHY Channel Mapping 3.2. Virtualization Support 3.3. TLP Bypass Mode
3.2. Virtualization Support x
3.2.1. SR-IOV Support 3.2.2. VirtIO Support
3.2.1. SR-IOV Support x
3.2.1.1. SR-IOV Supported Features List 3.2.1.2. Implementation 3.2.1.3. VF to PF Mapping 3.2.1.4. Function Level Reset (FLR)
3.2.1.2. Implementation x
3.2.1.2.1. VF Error Flag Interface (for x16/x8 Cores Only)
3.2.2. VirtIO Support x
3.2.2.1. VirtIO Supported Features List 3.2.2.2. Overview 3.2.2.3. Parameters 3.2.2.4. VirtIO PCI Configuration Access Interface 3.2.2.5. Registers
3.2.2.5. Registers x
3.2.2.5.1. VirtIO Common Configuration Capability Register (Address: 0x012) 3.2.2.5.2. VirtIO Common Configuration BAR Indicator Register (Address: 0x013) 3.2.2.5.3. VirtIO Common Configuration BAR Offset Register (Address: 0x014) 3.2.2.5.4. VirtIO Common Configuration Structure Length Register (Address 0x015) 3.2.2.5.5. VirtIO Notifications Capability Register (Address: 0x016) 3.2.2.5.6. VirtIO Notifications BAR Indicator Register (Address: 0x017) 3.2.2.5.7. VirtIO Notifications BAR Offset Register (Address: 0x018) 3.2.2.5.8. VirtIO Notifications Structure Length Register (Address: 0x019) 3.2.2.5.9. VirtIO Notifications Notify Off Multiplier Register (Address: 0x01A) 3.2.2.5.10. VirtIO ISR Status Capability Register (Address: 0x02F) 3.2.2.5.11. VirtIO ISR Status BAR Indicator Register (Address: 0x030) 3.2.2.5.12. VirtIO ISR Status BAR Offset Register (Address: 0x031) 3.2.2.5.13. VirtIO ISR Status Structure Length Register (Address: 0x032) 3.2.2.5.14. VirtIO Device Specific Capability Register (Address: 0x033) 3.2.2.5.15. VirtIO Device Specific BAR Indicator Register (Address: 0x034) 3.2.2.5.16. VirtIO Device Specific BAR Offset Register (Address 0x035) 3.2.2.5.17. VirtIO Device Specific Structure Length Register (Address: 0x036) 3.2.2.5.18. VirtIO PCI Configuration Access Capability Register (Address: 0x037) 3.2.2.5.19. VirtIO PCI Configuration Access BAR Indicator Register (Address: 0x038) 3.2.2.5.20. VirtIO PCI Configuration Access BAR Offset Register (Address: 0x039) 3.2.2.5.21. VirtIO PCI Configuration Access Structure Length Register (Address: 0x03A) 3.2.2.5.22. VirtIO PCI Configuration Access Data Register (Address: 0x03B)
3.3. TLP Bypass Mode x
3.3.1. Overview 3.3.2. Register Settings for the TLP Bypass Mode 3.3.3. User Avalon Memory-mapped Interface 3.3.4. Avalon® Streaming Interface
3.3.2. Register Settings for the TLP Bypass Mode x
3.3.2.1. TLPBYPASS_ERR_EN (Address 0x1314) 3.3.2.2. TLPBYPASS_ERR_STATUS (Address 0x1310)
3.3.4. Avalon® Streaming Interface x
3.3.4.1. Configuration TLP 3.3.4.2. Transmit Interface 3.3.4.3. Receive Interface 3.3.4.4. Malformed TLP 3.3.4.5. ECRC
4. Interfaces x
4.1. Overview 4.2. Clocks and Resets 4.3. Serial Data Interface 4.4. PCI Express Mode 4.5. PIPE Direct Mode
4.2. Clocks and Resets x
4.2.1. Clocks 4.2.2. Resets
4.4. PCI Express Mode x
4.4.1. Avalon® Streaming Interface 4.4.2. Precision Time Measurement (PTM) Interface 4.4.3. Interrupt Interface 4.4.4. Hard IP Reconfiguration Interface 4.4.5. Error Interface 4.4.6. Completion Timeout Interface 4.4.7. Configuration Intercept Interface 4.4.8. Power Management Interface 4.4.9. Hard IP Status Interface 4.4.10. Page Request Services (PRS) Interface 4.4.11. Function-Level Reset (FLR) Interface 4.4.12. SR-IOV VF Error Flag Interface 4.4.13. General Purpose VSEC Interface
4.4.1. Avalon® Streaming Interface x
4.4.1.1. TLP Header and Data Alignment for the Avalon® streaming RX and TX Interfaces 4.4.1.2. Credit Control 4.4.1.3. Avalon® Streaming RX Interface 4.4.1.4. Avalon® Streaming TX Interface 4.4.1.5. Tag Allocation
4.4.1.2. Credit Control x
4.4.1.2.1. Credit Interface - Data and Header 4.4.1.2.2. Credit Initialization 4.4.1.2.3. Credit Update/Release 4.4.1.2.4. RX Flow Control Interface 4.4.1.2.5. TX Flow Control Interface
4.4.1.4. Avalon® Streaming TX Interface x
4.4.1.4.1. Avalon® Streaming TX Interface tx_st_ready_o Behavior
4.4.1.5. Tag Allocation x
4.4.1.5.1. Completion Buffer Size
4.4.3. Interrupt Interface x
4.4.3.1. Legacy Interrupts 4.4.3.2. MSI 4.4.3.3. MSI-X
4.4.3.3. MSI-X x
4.4.3.3.1. Implementing MSI-X Interrupts
4.4.8. Power Management Interface x
4.4.8.1. Endpoint D3Hot Entry 4.4.8.2. Endpoint D3Hot Exit
4.5. PIPE Direct Mode x
4.5.1. Data Signals 4.5.2. Message Channel 4.5.3. Deskew Channel 4.5.4. PIPE Direct Reset Sequence 4.5.5. PIPE Direct Speed Change 4.5.6. PIPE Lane Reset Staggering 4.5.7. Unused Lanes in PIPE Direct Mode 4.5.8. PIPE Direct Mode TX/RX Datapaths
4.5.1. Data Signals x
4.5.1.1. Transmit Signals 4.5.1.2. Receive Signals
5. Parameters x
5.1. Top-Level Settings 5.2. Core Parameters
5.2. Core Parameters x
5.2.1. Avalon Parameters 5.2.2. Base Address Registers 5.2.3. PCI Express and PCI Capabilities Parameters
5.2.3. PCI Express and PCI Capabilities Parameters x
5.2.3.1. Device Capabilities 5.2.3.2. VirtIO Parameters 5.2.3.3. Link Capabilities 5.2.3.4. Legacy Interrupt Pin Register 5.2.3.5. MSI Capabilities 5.2.3.6. MSI-X Capabilities 5.2.3.7. Slot Capabilities 5.2.3.8. Latency Tolerance Reporting (LTR) 5.2.3.9. Process Address Space ID (PASID) 5.2.3.10. Device Serial Number Capability 5.2.3.11. Page Request Service (PRS) 5.2.3.12. Access Control Service (ACS) 5.2.3.13. Power Management 5.2.3.14. Vendor Specific Extended Capability (VSEC) Registers 5.2.3.15. TLP Processing Hints (TPH) 5.2.3.16. Address Translation Services (ATS) Capabilities 5.2.3.17. Precision Time Management (PTM)
C. Implementation of Address Translation Services (ATS) in Endpoint Mode x
C.1. Sending Translated/Untranslated Requests C.2. Sending a Page Request Message from the Endpoint (EP) to the Root Complex (RC) C.3. Invalidating Requests/Completions
D. Packets Forwarded to the User Application in TLP Bypass Mode x
D.1. EP TLP Bypass Mode (Upstream) D.2. RC TLP Bypass Mode (Downstream)
1. Introduction
2. IP Architecture and Functional Description
3. Advanced Features
4. Interfaces
5. Parameters
6. R-tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide Archives
7. Document Revision History for the R-tile Avalon® Streaming Intel FPGA IP for PCI Express User Guide
A. Configuration Space Registers
B. Root Port Enumeration
C. Implementation of Address Translation Services (ATS) in Endpoint Mode
D. Packets Forwarded to the User Application in TLP Bypass Mode

2.3.3.3. Transaction Layer Overview

The following figure shows the major blocks in the R-tile Avalon® -ST IP for PCI Express Transaction Layer:

Figure 7. R-tile Avalon® -ST IP for PCI Express Transaction Layer Block Diagram

The RAS (Reliability, Availability, and Serviceability) block includes a set of features to maintain the integrity of the link.

For example: Transaction Layer inserts an optional ECRC in the transmit logic and checks it in the receive logic to provide End-to-End data protection.

When the application logic sets the TLP Digest (TD) bit in the Header of the TLP, the R-tile Avalon® -ST IP for PCIe will append the ECRC automatically.

Note: In TLP Bypass mode, the PCIe Hard IP does not generate/check the ECRC and will not remove it if the received TLP has the ECRC.

The TX block sends out the TLPs that it receives as-is. It also sends the information about non-posted TLPs to the CPL Timeout Block for CPL timeout detection.

The R-tile Avalon® -ST IP for PCI Express RX block consists of two main blocks:
  • Filtering block: This module checks if the TLP is good or bad and generates the associated error message and completion. It also tracks received completions and updates the completion timeout (CPL timeout) block.
  • RX Buffer Queue: The R-tile IP for PCIe has separate queues for posted/non-posted transactions and completions. This avoids head-of-queue blocking on the received TLPs and provides flexibility to extract TLPs according to the PCIe ordering rules.
Figure 8. R-tile Avalon® -ST IP for PCI Express RX Block Overview
Note: The Received CPL Processing block includes the CPL tracking mechanism.
Note: The Avalon-ST interface uses a split-bus architecture. In the x16 and x8 configurations, the 1024-bit Avalon-ST data bus consists of four segments of 256-bit data. This is done to improve the bandwidth efficiency of this interface. With this split-bus architecture, multiple TLP packets can be transmitted or received in a single clock cycle. For more details, refer to Avalon Streaming Interface.
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