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

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ID 683501
Date 6/20/2022
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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
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. 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
2.3.2. Reset x
2.3.2.1. Single PERST 2.3.2.2. Independent PERST
2.3.2.2. Independent PERST x
2.3.2.2.1. REFCLK and PERST Guidelines when Using Independent PERST
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
2.3.3.3. Transaction Layer Overview x
2.3.3.3.1. Deferrable Memory Write (DMWr)
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. 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
4.3.1.4. Avalon® Streaming TX Interface x
4.3.1.4.1. Avalon® Streaming TX Interface 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 Management (PTM)
6. Troubleshooting/Debugging x
6.1. Using the Hard IP Reconfiguration Interface for Debugging 6.2. Debug Toolkit
6.1. Using the Hard IP Reconfiguration Interface for Debugging x
6.1.1. Using the Hard IP Reconfiguration Interface to Enable and Read ECRC and LCRC Error Counts
6.2. Debug Toolkit x
6.2.1. Overview 6.2.2. Enabling the R-Tile Debug Toolkit 6.2.3. Launching the R-tile Debug Toolkit 6.2.4. Using the R-Tile Debug Toolkit
6.2.4. Using the R-Tile Debug Toolkit x
6.2.4.1. R-Tile Information 6.2.4.2. Event Counters 6.2.4.3. Configuration Space
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. 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

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 44. PIPE Direct Speed Change

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.

  • Steps (a, b, c, d): The Soft IP controller stops the data transmission on the TX data path signals in preparation for the speed change event.
  • Step (e): Once ready, the Soft IP Controller will set the targeted rate on the ln0_pipe_direct_rate_i signal.
  • Steps (f, g, h): The ln_pipe_direct_reset_status_n_o signal goes low, invalidating any further data received on the ln0_pipe_direct_rxdata_o bus. Additionally, the ln0_cdrlock2data_o signal goes low.
    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.
  • Steps (i,j): The ln0_pipe_direct_rxdatavalid0_o and ln0_pipe_direct_rxdatavalid1_o signal go low.
    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.
  • Step (k): The ln0_pipe_direct_pld_rx_clk_out_o stops toggling.
  • Steps (l, m): The R-Tile Avalon Streaming IP asserts ln0_pipe_direct_pclkchangeok_o and the Soft IP Controller confirms by driving high the ln0_pipe_direct_pclkchangeack_i signal.
  • Step (n): The ln0_pipe_direct_cdrlockstatus_o signal goes low until the R-Tile Avalon Streaming IP locks to the new clock frequency.
  • Step (o): The ln0_pipe_direct_cdrlockstatus_o signal goes high once the R-Tile Avalon Streaming IP locks to the new clock frequency.
  • Steps (p, q): The R-Tile Avalon Streaming IP confirms a successful rate change with a single pulse on the ln0_pipe_direct_phystatus_o signal and by driving low the ln0_pipe_direct_pclkchangeok_o signal.
  • Step (r): The Soft IP Controller acknowledges the rate change by driving low the ln0_pipe_direct_pclkchangeack_i signal.
  • Steps (s, t, u, v): The Soft IP Controller starts the data transmission at the new rate on the TX data path signals.
  • Steps (w, x, y): The ln0_cdrlock2data_o signal is driven high by the R-Tile Avalon Streaming IP. The ln0_pipe_direct_rxdatavalid0_o and the ln0_pipe_direct_rxdatavalid1_o signals go high.
    Note: The RX data is not valid until the corresponding ln_pipe_direct_reset_status_n_o lane signal goes high.
  • Step (z): The corresponding ln_pipe_direct_reset_status_n_o lane signal goes high. This qualifies the RX data along with the ln0_pipe_direct_rxdatavalid0_o and ln0_pipe_direct_rxdatavalid1_o signals.
Level Two Title