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

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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

2.3.2.2. Independent PERST

The R-Tile Avalon® Streaming IP for PCIe allows further flexibility to handle independent reset operation for each of the active PCIe cores. The active PCIe cores depend on the Configuration Mode selected for the IP. For more information on the Configuration Modes, refer to Configuration Modes Supported by the R-tile Avalon® Streaming IP for PCI Express.

When you enable the Enable Independent Perst parameter in the IP Parameter Editor, the additional pX_cold_perst_n_i, pX_warm_perst_n_i, and pX_ip_rst_n_o ports become available.

Consider the following guidelines for handling independent reset operations:
  • pin_perst_n or pX_cold_perst_n_i input ports can trigger a cold reset. This will clear sticky bits and reset the physical layer.
  • pX_warm_perst_n_i input ports can trigger a warm reset. This will not clear the sticky bits but will reset the physical layer.
    Input Port Used Sticky Bits Clearing Non-Sticky Bits Clearing PHY Lane Reset
    pin_perst_n Yes Yes Yes
    pX_cold_perst_n_i Yes Yes Yes
    pX_warm_perst_n_i No Yes Yes
  • pin_perst_n has the highest priority for reset over the pX_cold_perst_n_i or pX_warm_perst_n_i ports.

  • When pin_perst_n is asserted (i.e. low), all active PCIe cores will reset.

  • When pin_perst_n is deasserted (i.e. high), the pX_cold_perst_n_i input ports can be used to trigger a cold reset operation on each of the PCIe cores independently.

  • When pin_perst_n is deasserted (i.e. high), the pX_warm_perst_n_i input ports can be used to trigger a warm reset operation on each of the PCIe cores independently.
    Figure 6.  pX_cold_perst_n_i/pX_warm_perst_n_i vs. pin_perst_n Behavior
    Figure 7.  pX_cold_perst_n_i/pX_warm_perst_n_i Behavior
  • Concurrent assertions of the reset input ports pin_perst_n, pX_cold_perst_n_i and pX_warm_perst_n_i are not supported.
  • Usage of the pX_cold_perst_n_i to perform a cold reset to one of the active cores must happen only after the deassertion (i.e. high) of the corresponding pX_reset_status_n port. As an example, in Configuration Mode 2 (x8x8), in order to trigger an independent cold reset operation on p0_cold_perst_n_i, the p0_reset_status_n must be deasserted (i.e. high).
  • Usage of the pX_warm_perst_n_i to perform a warm reset to one of the active cores must happen only after the deassertion (i.e. high) of the corresponding pX_reset_status_n port. As an example, in Configuration Mode 2 (x8x8), in order to trigger an independent warm reset operation on p0_warm_perst_n_i, the p0_reset_status_n must be deasserted (i.e. high).
  • Similarly to the pin_perst_n, once pX_cold_perst_n_i has been asserted (i.e. low), the assertion needs to be held for a minimum of 100us.
  • Similarly to the pin_perst_n, once pX_warm_perst_n_i has been asserted (i.e. low), the assertion needs to be held for a minimum of 100us.
    Figure 8. Interval Between Subsequent Independent PERST Operations
  • pX_cold_perst_n_i or pX_warm_perst_n_i assertion should be avoided during a functional-level reset or before a functional-level reset is completed since this could impact the link training process. In case this occurs, assert pin_perst_n to properly complete the link training process.
  • When the pX_cold_perst_n_i or pX_warm_perst_n_i ports are routed to General Purpose I/Os (GPIOs), the Application logic must implement a debounce logic to prevent the switch bouncing and triggering unintentional assertions. The debounce logic consists of a counter that waits for the signal to stabilize before propagating it to the targeted port. In case these ports are not routed to GPIOs and are being used by internal fabric logic only, the debounce logic is not necessary.
    Figure 9.  pX_cold_perst_n_i/pX_warm_perst_n_i Signals Before and After Debounce Logic

Section Content
REFCLK and PERST Guidelines when Using Independent PERST

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