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

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ID 683501
Date 3/28/2022
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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. 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. 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
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. 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. 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 (Endpoint Only) 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 (Endpoint Only) 4.4.11. Function-Level Reset (FLR) Interface (Endpoint Only) 4.4.12. SR-IOV VF Error Flag Interface (Endpoint Only) 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. D3Hot Entry 4.4.8.2. D3Hot Exit 4.4.8.3. D3Cold Entry 4.4.8.4. D3Cold Exit
4.4.8.2. D3Hot Exit x
4.4.8.2.1. D3Hot Exit Initiated by Host 4.4.8.2.2. D3Hot Exit Initiated by EP
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
4.5.1. Data Signals x
4.5.1.1. Transmit Signals 4.5.1.2. Receive Signals
4.5.3. Deskew Channel x
4.5.3.1. MAC to PHY (M2P) Signals 4.5.3.2. 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)
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. 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

4.5.4. PIPE Direct Reset Sequence

In PIPE Direct mode, your application logic is responsible for managing most of the PHY reset sequence in the FPGA fabric. The following figure describes the required sequence.

Figure 37. PIPE Direct Reset Sequence

Below are the steps required for the reset sequence and the TX/RX data transfer for lane 0 in the R-Tile Avalon Streaming IP when configured in PIPE-D mode. This behavior applies in the same way for other lanes.

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

For the TX path:
  1. Step (a) : ninit_done is driven low by the Reset Release IP indicating the FGPA fabric is configured. The Soft IP controller should be in reset until this signal is low.
  2. Step (b) : pin_perst_n_o is driven high by the R-Tile Avalon Streaming IP. This signal reflects the PERTS# signal at the board level.
  3. Step (c) : lnX_pipe_direct_tx_transfer_en_o is driven high by the R-Tile Avalon Streaming IP indicating the EMIB bridge between the R-Tile Avalon Streaming IP and the FPGA fabric is ready.
  4. Step (d) : lnX_pipe_direct_pld_pcs_rst_n_i is driven high by the Soft IP controller. The Soft IP controller must also drive high the per-lane lnX_pipe_direct_pld_pcs_rst_n_i signal to come out of reset after the per-lane lnX_pipe_direct_tx_transfer_en_o signal is driven high.
  5. Step (e) : pipe_direct_pld_tx_clk_out_o becomes active as the TX clock output to be used by the Soft IP controller for the TX path.
  6. Step (f) : lnX_pipe_direct_phystatus_o is driven low by the R-Tile Avalon Streaming IP indicating a reset exit.
  7. Step (g) : lnX_pipe_direct_phystatus_o is pulsed and in
  8. Step (h) : lnX_pipe_direct_rx_status_o is pulsed as well. Both pulses confirm to the Soft IP controller the RX detection.
  9. Step (j) : The Soft IP controller starts sending data on the lnX_pipe_direct_txdata_i bus along with its corresponding lnX_pipe_direct_txdatavalid0_i at Step (k) and lnX_pipe_direct_txdatavalid1_i signals at Step (l). Refer to PIPE Direct TX Datapath for additional details.
For the RX path:
  1. Step (m) : After TX data is transmitted from the Soft IP controller and once enough RX data has been received from the link partner to recover the clock, the lnX_pipe_direct_cdrlockstatus_o signal is driven high.
  2. Step (n) : The lnX_pipe_direct_cdrlock2data_o signal is driven high indicating the CDR has locked to the data being received.
  3. Step (o) : The lnX_pipe_direct_rx_clk_out_o signal becomes active as the RX clock output to be used by the Soft IP controller for the RX data path.
  4. Step (p) : The ln_pipe_direct_reset_status_n_o signal is driven high by the R-Tile Avalon Streaming IP indicating the RX data path is out of reset.
  5. Step (q) : The Soft IP controller starts sampling data on the lnX_pipe_direct_rxdata_o while qualifying the data with its corresponding lnX_pipe_direct_rxdatavalid0_i and lnX_pipe_direct_rxdatavalid1_i signals. Application logic needs to wait for the assertion of the corresponding lane's ln_pipe_direct_reset_status_n_o[15:0] to sample the Rx data. Refer to PIPE Direct RX Datapath for additional details.
Level Two Title