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

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ID 683501
Date 4/10/2024
Public
Document Table of Contents
Document Table of Contents x
1. About the R-Tile Avalon® Streaming Intel® FPGA IP for PCI Express 2. IP Architecture and Functional Description 3. Advanced Features 4. Interfaces 5. Parameters 6. Troubleshooting/Debugging 7. R-Tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide Archives 8. 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 E. Margin Masks for the R-Tile Avalon Streaming Intel FPGA IP for PCI Express
1. About the R-Tile Avalon® Streaming Intel® FPGA IP 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 Support Levels
1.1. Overview x
1.1.1. Standards and Specifications Compliance
1.2. Features x
1.2.1. Multifunction and Virtualization Features
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
2.2.2. Reset x
2.2.2.1. Single PERST 2.2.2.2. Independent PERST Pins 2.2.2.3. Independent GPIO PERST
2.2.2.2. Independent PERST Pins x
2.2.2.2.1. REFCLK and PERST Guidelines When Using Independent PERST Pins
2.2.2.3. Independent GPIO PERST x
2.2.2.3.1. REFCLK and PERST Guidelines when Using Independent GPIO PERST
2.2.3. PCI Express Protocol Stack x
2.2.3.1. PMA 2.2.3.2. Data Link Layer Overview 2.2.3.3. Transaction Layer Overview
2.2.3.3. Transaction Layer Overview x
2.2.3.3.1. Deferrable Memory Write (DMWr)
2.3. PIPE Direct Mode x
2.3.1. Clocking 2.3.2. Reset 2.3.3. PIPE Layer
2.3.3. PIPE Layer x
2.3.3.1. Preset Mappings
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. Hard IP Reconfiguration 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. Clocks and Resets 4.2. Serial Data Interface 4.3. PCI Express Mode 4.4. PIPE Direct Mode
4.1. Clocks and Resets x
4.1.1. Clocks 4.1.2. Resets
4.3. PCI Express Mode x
4.3.1. Avalon® Streaming Interface 4.3.2. Precision Time Measurement (PTM) Interface (Endpoint Only) 4.3.3. Interrupt Interface 4.3.4. Hard IP Reconfiguration Interface 4.3.5. Error Interface 4.3.6. Completion Timeout Interface 4.3.7. Configuration Intercept Interface 4.3.8. Power Management Interface 4.3.9. Hard IP Status Interface 4.3.10. Page Request Services (PRS) Interface (Endpoint Only) 4.3.11. Function-Level Reset (FLR) Interface (Endpoint Only) 4.3.12. SR-IOV VF Error Flag Interface (Endpoint Only) 4.3.13. General Purpose VSEC Interface
4.3.1. Avalon® Streaming Interface x
4.3.1.1. TLP Header and Data Alignment for the Avalon® streaming RX and TX Interfaces 4.3.1.2. Credit Control 4.3.1.3. Avalon® Streaming RX Interface 4.3.1.4. Avalon® Streaming TX Interface 4.3.1.5. Tag Allocation
4.3.1.2. Credit Control x
4.3.1.2.1. Credit Interface - Data and Header 4.3.1.2.2. Credit Initialization 4.3.1.2.3. Credit Update/Release 4.3.1.2.4. RX Flow Control Interface 4.3.1.2.5. TX Flow Control Interface
4.3.1.3. Avalon® Streaming RX Interface x
4.3.1.3.1. Application Logic Guidelines for the Avalon Streaming RX Interface
4.3.1.4. Avalon® Streaming TX Interface x
4.3.1.4.1. Application Logic Guidelines for the Avalon Streaming TX Interface 4.3.1.4.2. Avalon® Streaming TX Interface pX_tx_st_ready_o Behavior
4.3.1.5. Tag Allocation x
4.3.1.5.1. Completion Buffer Size
4.3.3. Interrupt Interface x
4.3.3.1. Legacy Interrupts 4.3.3.2. MSI 4.3.3.3. MSI-X
4.3.3.3. MSI-X x
4.3.3.3.1. Implementing MSI-X Interrupts
4.3.8. Power Management Interface x
4.3.8.1. D3Hot Entry 4.3.8.2. D3Hot Exit 4.3.8.3. D3Cold Entry 4.3.8.4. D3Cold Exit
4.3.8.2. D3Hot Exit x
4.3.8.2.1. D3Hot Exit Initiated by Host 4.3.8.2.2. D3Hot Exit Initiated by EP
4.4. PIPE Direct Mode x
4.4.1. Data Signals 4.4.2. Command and Status Signals 4.4.3. Message Bus Signals 4.4.4. Deskew Signals 4.4.5. PIPE Direct Reset Sequence 4.4.6. PIPE Direct Speed Change 4.4.7. PIPE Lane Reset Staggering 4.4.8. Unused Lanes in PIPE Direct Mode
4.4.1. Data Signals x
4.4.1.1. Transmit Signals 4.4.1.2. Receive Signals
4.4.4. Deskew Signals x
4.4.4.1. MAC to PHY (M2P) Signals 4.4.4.2. PHY to MAC (P2M) 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 Measurement (PTM)
6. Troubleshooting/Debugging x
6.1. Hardware Debug 6.2. Operating System Tools and Utilities 6.3. Signal Tap Logic Analyzer 6.4. Using the Hard IP Reconfiguration Interface for Debugging 6.5. Other Interfaces That Can Be Used for Debug Activities 6.6. Debug Toolkit
6.1. Hardware Debug x
6.1.1. Debugging Link Training Issues 6.1.2. Debugging Device Enumeration Issues 6.1.3. Debugging Data Transfer and Performance Issues
6.1.3. Debugging Data Transfer and Performance Issues x
6.1.3.1. Advanced Error Reporting (AER)
6.2. Operating System Tools and Utilities x
6.2.1. Using lspci Utility to Read Negotiated Link Speed
6.4. Using the Hard IP Reconfiguration Interface for Debugging x
6.4.1. Using the Hard IP Reconfiguration Interface to Enable and Read ECRC and LCRC Error Counts
6.6. Debug Toolkit x
6.6.1. Overview 6.6.2. Enabling the R-Tile Debug Toolkit 6.6.3. Launching the R-Tile Debug Toolkit 6.6.4. Using the R-Tile Debug Toolkit
6.6.4. Using the R-Tile Debug Toolkit x
6.6.4.1. R-Tile Information 6.6.4.2. Event Counters 6.6.4.3. Link Inspector 6.6.4.4. Configuration Space 6.6.4.5. Channel Parameters
6.6.4.5. Channel Parameters x
6.6.4.5.1. General PHY 6.6.4.5.2. Tx Path 6.6.4.5.3. Rx Path 6.6.4.5.4. Lane Margining
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. Upstream TLP Bypass Mode D.2. Downstream TLP Bypass Mode
E. Margin Masks for the R-Tile Avalon Streaming Intel FPGA IP for PCI Express x
E.1. Margin Masks Overview E.2. 5x5 Testing Efficiency E.3. Debug Toolkit Margin Methodology
E.2. 5x5 Testing Efficiency x
E.2.1. First Time Testing E.2.2. Spot Check Testing
E.3. Debug Toolkit Margin Methodology x
E.3.1. Debug Toolkit Testing Process
1. About the R-Tile Avalon® Streaming Intel® FPGA IP for PCI Express
2. IP Architecture and Functional Description
3. Advanced Features
4. Interfaces
5. Parameters
6. Troubleshooting/Debugging
7. R-Tile Avalon® Streaming Intel® FPGA IP for PCI Express* User Guide Archives
8. 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
E. Margin Masks for the R-Tile Avalon Streaming Intel FPGA IP for PCI Express

4.4.6. PIPE Direct Speed Change

In the PIPE Direct Data mode, the clock for the RX datapath is sourced from the PHY recovered clock (pipe_direct_pld_rx_clk_out_o). The PHY recovered clock changes frequency when the PHY trains from Gen1 to Gen5. During the PIPE Direct RX rate change, the following sequence needs to be adhered to.

The soft IP controller first changes the rate or width if required. The R-Tile Avalon Streaming IP only asserts lnX_pipe_direct_pclkchangeok_o after the Soft IP controller has made the changes. The Soft IP controller asserts lnX_pipe_direct_pclkchangeack_i when the change is complete and stable. After the Soft IP controller asserts lnX_pipe_direct_pclkchangeack_i, the R-Tile Avalon Streaming IP responds by asserting lnX_pipe_direct_phystatus_o for one cycle and deasserting lnX_pipe_direct_pclkchangeok_o at the same time as lnX_pipe_direct_phystatus_o. The Soft IP controller deasserts lnX_pipe_direct_pclkchangeack_i when lnX_pipe_direct_pclkchangeok_o is sampled low.

As a reference, the following diagram illustrates the speed change from Gen1 to Gen5.
Note: Although the diagram below illustrates a speed change from Gen1 to Gen5, the overall sequence applies to all speed changes. However, the final value of ln0_pipe_direct_rate_i varies depending on what the final speed is.
Figure 47. PIPE Direct Speed Change
Note: As per the PHY Interface for PCI Express Specification, Version 5.1.1, the TX data valid signal must be asserted whenever TX electrical idle toggles. The PHY will mask off the TX data as long as TX electrical idle is asserted.
Note: The Rx data must be qualified with an AND operation between the corresponding ln_pipe_direct_reset_status_n_o lane signal, ln0_pipe_direct_rxdatavalid0_o and ln0_pipe_direct_rxdatavalid1_o.
Note: The RX data is not valid until the corresponding ln_pipe_direct_reset_status_n_o lane signal goes high.

Below are the steps required for the speed change sequence for lane 0 in the R-Tile Avalon Streaming IP when configured in PIPE Direct mode. This behavior also applies to other lanes and other speed rates.

Note that each of the steps required correlates with the corresponding letter in the waveforms.

Step (a) : The Soft IP controller initiates rate change by transitioning LTSSM State into Recovery.

Step (b) : The soft IP controller asserts lnX_pipe_direct_standby_i signal to indicate the PHY transition into standby mode.

Step (c) : The soft IP controller asserts lnX_pipe_direct_txelecidle_i while lnX_pipe_direct_txdatavalid0_i and lnX_pipe_direct_txdatavalid1_i are asserted. The soft IP controller deasserts lnX_pipe_direct_txdatavalid0_i, lnX_pipe_direct_txdatavalid1_i signal after asserting lnX_pipe_direct_txelecidle_i.

Step (d) : The soft IP controller changes the rate by changing the lnX_pipe_direct_rate signal.

Step (e) : The R-tile Avalon Streaming IP drives the lnX_pipe_direct_reset_status_n_o signal low indicating RX datapath is in reset.

Step (f) : The R-tile Avalon Streaming IP asserts lnX_pipe_direct_pclkratechangeok_o indicating the PHY is changing the pclk.

Step (g) : The soft IP controller asserts the lnX_pipe_direct_pclkchangeack_i indicating the pclk change is acknowledged by the soft IP controller.

Step (h) : The lnX_pipe_direct_phystatus_o is pulsed to acknowledge rate change.

Step (i) : The R-tile Avalon Streaming IP deasserts lnX_pipe_direct_pclkratechangeok_o indicating the PHY completed the pclk change for the new speed.

Step (j) : The soft IP controller deasserts the lnX_pipe_direct_pclkchangeack_i indicating the pclk change completion is acknowledged by the soft IP controller.

Step (k) : The soft IP controller deasserts lnX_pipe_direct_standby_i signal to indicate the PHY transition into active mode.

Step (l) : The soft IP controller deasserts lnX_pipe_direct_txelecidle_i after lnX_pipe_direct_txdatavalid0_i and lnX_pipe_direct_txdatavalid1_i are asserted. The soft IP controller sends valid data on lnX_pipe_direct_txdata once the lnX_pipe_direct_txelecidle_i is deasserted.

Step (m) : The R-tile Avalon Streaming IP asserts the lnX_pipe_direct_cdrlock2data_o indicating RX CDR is locked to data.

Step (n) : The R-tile Avalon Streaming IP drives the lnX_pipe_direct_reset_status_n_o signal high indicating the RX path is out of reset and RX data can be received on the RX datapath by the soft IP controller.

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