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

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ID 683501
Date 10/06/2021
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Document Table of Contents
Document Table of Contents x
1. Introduction 2. IP Architecture and Functional Description 3. Parameters 4. Interfaces 5. Advanced Features 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. PCIe Hard IP Mode 2.3. PIPE Direct Mode
2.2. PCIe Hard IP Mode x
2.2.1. Clocking 2.2.2. Reset 2.2.3. PCI Express Protocol Stack
2.2.3. PCI Express Protocol Stack x
2.2.3.1. PMA/PCS 2.2.3.2. Data Link Layer Overview 2.2.3.3. Transaction Layer Overview
2.3. PIPE Direct Mode x
2.3.1. Clocking 2.3.2. Reset 2.3.3. PIPE Layer
3. Parameters x
3.1. Top-Level Settings 3.2. Core Parameters
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
4.4.1.2.4. RX Flow Control Interface x
4.4.1.2.4.1. Completion Buffer Size
4.4.1.4. Avalon® Streaming TX Interface x
4.4.1.4.1. Avalon® Streaming TX Interface tx_st_ready_o Behavior
4.4.3. 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. Advanced Features x
5.1. PCIe Port Bifurcation and PHY Channel Mapping 5.2. Virtualization Support 5.3. TLP Bypass Mode
5.2. Virtualization Support x
5.2.1. SR-IOV Support 5.2.2. VirtIO Support
5.2.1. SR-IOV Support x
5.2.1.1. SR-IOV Supported Features List 5.2.1.2. Implementation 5.2.1.3. VF to PF Mapping 5.2.1.4. Function Level Reset (FLR)
5.2.1.2. Implementation x
5.2.1.2.1. VF Error Flag Interface (for x16/x8 Cores Only)
5.2.2. VirtIO Support x
5.2.2.1. VirtIO Supported Features List 5.2.2.2. Overview 5.2.2.3. Parameters 5.2.2.4. VirtIO PCI Configuration Access Interface 5.2.2.5. Registers
5.2.2.5. Registers x
5.2.2.5.1. VirtIO Common Configuration Capability Register (Address: 0x012) 5.2.2.5.2. VirtIO Common Configuration BAR Indicator Register (Address: 0x013) 5.2.2.5.3. VirtIO Common Configuration BAR Offset Register (Address: 0x014) 5.2.2.5.4. VirtIO Common Configuration Structure Length Register (Address 0x015) 5.2.2.5.5. VirtIO Notifications Capability Register (Address: 0x016) 5.2.2.5.6. VirtIO Notifications BAR Indicator Register (Address: 0x017) 5.2.2.5.7. VirtIO Notifications BAR Offset Register (Address: 0x018) 5.2.2.5.8. VirtIO Notifications Structure Length Register (Address: 0x019) 5.2.2.5.9. VirtIO Notifications Notify Off Multiplier Register (Address: 0x01A) 5.2.2.5.10. VirtIO ISR Status Capability Register (Address: 0x02F) 5.2.2.5.11. VirtIO ISR Status BAR Indicator Register (Address: 0x030) 5.2.2.5.12. VirtIO ISR Status BAR Offset Register (Address: 0x031) 5.2.2.5.13. VirtIO ISR Status Structure Length Register (Address: 0x032) 5.2.2.5.14. VirtIO Device Specific Capability Register (Address: 0x033) 5.2.2.5.15. VirtIO Device Specific BAR Indicator Register (Address: 0x034) 5.2.2.5.16. VirtIO Device Specific BAR Offset Register (Address 0x035) 5.2.2.5.17. VirtIO Device Specific Structure Length Register (Address: 0x036) 5.2.2.5.18. VirtIO PCI Configuration Access Capability Register (Address: 0x037) 5.2.2.5.19. VirtIO PCI Configuration Access BAR Indicator Register (Address: 0x038) 5.2.2.5.20. VirtIO PCI Configuration Access BAR Offset Register (Address: 0x039) 5.2.2.5.21. VirtIO PCI Configuration Access Structure Length Register (Address: 0x03A) 5.2.2.5.22. VirtIO PCI Configuration Access Data Register (Address: 0x03B)
5.3. TLP Bypass Mode x
5.3.1. Overview 5.3.2. Register Settings for the TLP Bypass Mode 5.3.3. User Avalon Memory-mapped Interface 5.3.4. Avalon® Streaming Interface
5.3.2. Register Settings for the TLP Bypass Mode x
5.3.2.1. TLPBYPASS_ERR_EN (Address 0x1314) 5.3.2.2. TLPBYPASS_ERR_STATUS (Address 0x1310)
5.3.4. Avalon® Streaming Interface x
5.3.4.1. Configuration TLP 5.3.4.2. Transmit Interface 5.3.4.3. Receive Interface 5.3.4.4. Malformed TLP 5.3.4.5. ECRC
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. Parameters
4. Interfaces
5. Advanced Features
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

4.4.1.2.2. Credit Initialization

Each side will initialize its credit counters during the initialization stage. In this stage, the sink communicates its total buffer size available to the source. The sink initiates the initialization phase by asserting the *crdt_init signal. If the source is ready for initialization, it asserts *crdt_init_ack in response. After receiving *crdt_init_ack, the sink asserts the *crdt_update signal to communicate the buffer size available to receive transactions.

The source increments its internal credit counter by *crdt_update_cnt for every cycle it encounters an assertion of the *update signal for the header credit.

The deassertion of *init signals the completion of the initialization phase. There is a required minimum of 2 clock cycles separation between the deassertion of the *update and *init signals.

Figure 22. Credit Initialization
Note: The internal signals in the figure above are not exposed to the application logic.

Re-initialization is generally not required. However, if required (for example, if the application logic wants to change the buffer size), it can be done only when the source and sink are both in IDLE state. The IDLE state for the sink is when its receiver buffer is empty. For the source, the IDLE state is when it has nothing to transmit when the initialization request is made.

Level Two Title