Cyclone® V Avalon® Streaming (Avalon-ST) Interface for PCIe* Solutions User Guide

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ID 683524
Date 6/02/2020
Public
Document Table of Contents
Document Table of Contents x
1. Datasheet 2. Getting Started with the Cyclone V Hard IP for PCI Express 3. Parameter Settings 4. Interfaces and Signal Descriptions 5. Registers 6. Interrupts 7. Error Handling 8. IP Core Architecture 9. Transaction Layer Protocol (TLP) Details 10. Throughput Optimization 11. Design Implementation 12. Additional Features 13. Hard IP Reconfiguration 14. Transceiver PHY IP Reconfiguration 15. Testbench and Design Example 16. Debugging A. Frequently Asked Questions for PCI Express B. Lane Initialization and Reversal C. Document Revision History
1. Datasheet x
1.1. Cyclone V Avalon-ST Interface for PCIe Datasheet 1.2. Features 1.3. Release Information 1.4. Device Family Support 1.5. Configurations 1.6. Example Designs 1.7. Debug Features 1.8. IP Core Verification 1.9. Performance and Resource Utilization 1.10. Recommended Speed Grades 1.11. Creating a Design for PCI Express
1.8. IP Core Verification x
1.8.1. Compatibility Testing Environment
2. Getting Started with the Cyclone V Hard IP for PCI Express x
2.1. Qsys Design Flow 2.2. Modifying the Example Design 2.3. Using the IP Catalog To Generate Your Cyclone V Hard IP for PCI Express as a Separate Component
2.1. Qsys Design Flow x
2.1.1. Generating the Testbench 2.1.2. Simulating the Example Design 2.1.3. Generating Synthesis Files 2.1.4. Understanding the Files Generated 2.1.5. Understanding Physical Placement of the PCIe IP Core 2.1.6. Compiling the Design in the Quartus® Prime Software
3. Parameter Settings x
3.1. Avalon-ST System Settings 3.2. Link Capabilities 3.3. Port Function Parameters Shared Across All Port Functions 3.4. Port Function Parameters Defined Separately for All Port Functions
3.3. Port Function Parameters Shared Across All Port Functions x
3.3.1. Device Capabilities 3.3.2. Error Reporting 3.3.3. Link Capabilities 3.3.4. Slot Capabilities 3.3.5. Power Management
3.4. Port Function Parameters Defined Separately for All Port Functions x
3.4.1. Base Address Register (BAR) and Expansion ROM Settings 3.4.2. Base and Limit Registers for Root Ports 3.4.3. Device Identification Registers for Function <n> 3.4.4. Func <n> Device 3.4.5. Func <n> Link 3.4.6. Func <n> MSI and MSI-X Capabilities 3.4.7. Func <n> Legacy Interrupt
4. Interfaces and Signal Descriptions x
4.1. Clock Signals 4.2. Reset, Status, and Link Training Signals 4.3. ECRC Forwarding 4.4. Error Signals 4.5. Interrupts for Endpoints 4.6. Interrupts for Root Ports 4.7. Completion Side Band Signals 4.8. LMI Signals 4.9. Transaction Layer Configuration Space Signals 4.10. Hard IP Reconfiguration Interface 4.11. Power Management Signals 4.12. Physical Layer Interface Signals
4.9. Transaction Layer Configuration Space Signals x
4.9.1. Configuration Space Register Access Timing 4.9.2. Configuration Space Register Access
4.12. Physical Layer Interface Signals x
4.12.1. Serial Data Signals 4.12.2. PIPE Interface Signals 4.12.3. Test Signals
4.12.1. Serial Data Signals x
4.12.1.1. Physical Layout of Hard IP in Cyclone V Devices 4.12.1.2. Channel Placement in Cyclone V Devices
5. Registers x
5.1. Correspondence between Configuration Space Registers and the PCIe Specification 5.2. Type 0 Configuration Space Registers 5.3. Type 1 Configuration Space Registers 5.4. PCI Express Capability Structures 5.5. Intel-Defined VSEC Registers 5.6. Advanced Error Reporting Capability
5.5. Intel-Defined VSEC Registers x
5.5.1. CvP Registers
5.6. Advanced Error Reporting Capability x
5.6.1. Uncorrectable Internal Error Mask Register 5.6.2. Uncorrectable Internal Error Status Register 5.6.3. Correctable Internal Error Mask Register 5.6.4. Correctable Internal Error Status Register
6. Interrupts x
6.1. Interrupts for Endpoints 6.2. Interrupts for Root Ports
6.1. Interrupts for Endpoints x
6.1.1. MSI and Legacy Interrupts 6.1.2. MSI-X 6.1.3. Implementing MSI-X Interrupts 6.1.4. Legacy Interrupts
7. Error Handling x
7.1. Physical Layer Errors 7.2. Data Link Layer Errors 7.3. Transaction Layer Errors 7.4. Error Reporting and Data Poisoning 7.5. Uncorrectable and Correctable Error Status Bits
8. IP Core Architecture x
8.1. Top-Level Interfaces 8.2. Transaction Layer 8.3. Data Link Layer 8.4. Physical Layer 8.5. Multi-Function Support
8.1. Top-Level Interfaces x
8.1.1. Avalon-ST Interface 8.1.2. Clocks and Reset 8.1.3. Local Management Interface (LMI Interface) 8.1.4. Hard IP Reconfiguration 8.1.5. Transceiver Reconfiguration 8.1.6. Interrupts 8.1.7. PIPE
8.2. Transaction Layer x
8.2.1. Configuration Space
9. Transaction Layer Protocol (TLP) Details x
9.1. Supported Message Types 9.2. Transaction Layer Routing Rules 9.3. Receive Buffer Reordering
9.1. Supported Message Types x
9.1.1. INTX Messages 9.1.2. Power Management Messages 9.1.3. Error Signaling Messages 9.1.4. Locked Transaction Message 9.1.5. Slot Power Limit Message 9.1.6. Vendor-Defined Messages 9.1.7. Hot Plug Messages
9.3. Receive Buffer Reordering x
9.3.1. Using Relaxed Ordering
10. Throughput Optimization x
10.1. Throughput of Posted Writes 10.2. Throughput of Non-Posted Reads
11. Design Implementation x
11.1. Making Analog QSF Assignments Using the Assignment Editor 11.2. Making Pin Assignments to Assign I/O Standard to Serial Data Pins 11.3. Recommended Reset Sequence to Avoid Link Training Issues 11.4. SDC Timing Constraints
12. Additional Features x
12.1. Configuration over Protocol (CvP) 12.2. Autonomous Mode 12.3. ECRC
12.2. Autonomous Mode x
12.2.1. Enabling Autonomous Mode 12.2.2. Enabling CvP Initialization
12.3. ECRC x
12.3.1. ECRC on the RX Path 12.3.2. ECRC on the TX Path
14. Transceiver PHY IP Reconfiguration x
14.1. Connecting the Transceiver Reconfiguration Controller IP Core 14.2. Transceiver Reconfiguration Controller Connectivity for Designs Using CvP
15. Testbench and Design Example x
15.1. Endpoint Testbench 15.2. Root Port Testbench 15.3. Test Driver Module 15.4. Root Port Design Example 15.5. Root Port BFM Overview 15.6. BFM Procedures and Functions 15.7. Setting Up Simulation
15.1. Endpoint Testbench x
15.1.1. Endpoint Testbench for SR-IOV
15.5. Root Port BFM Overview x
15.5.1. BFM Memory Map 15.5.2. Configuration Space Bus and Device Numbering 15.5.3. Configuration of Root Port and Endpoint 15.5.4. Issuing Read and Write Transactions to the Application Layer
15.6. BFM Procedures and Functions x
15.6.1. ebfm_barwr Procedure 15.6.2. ebfm_barwr_imm Procedure 15.6.3. ebfm_barrd_wait Procedure 15.6.4. ebfm_barrd_nowt Procedure 15.6.5. ebfm_cfgwr_imm_wait Procedure 15.6.6. ebfm_cfgwr_imm_nowt Procedure 15.6.7. ebfm_cfgrd_wait Procedure 15.6.8. ebfm_cfgrd_nowt Procedure 15.6.9. BFM Configuration Procedures 15.6.10. BFM Shared Memory Access Procedures 15.6.11. BFM Log and Message Procedures 15.6.12. Verilog HDL Formatting Functions
15.6.9. BFM Configuration Procedures x
15.6.9.1. ebfm_cfg_rp_ep Procedure 15.6.9.2. ebfm_cfg_decode_bar Procedure
15.6.10. BFM Shared Memory Access Procedures x
15.6.10.1. Shared Memory Constants 15.6.10.2. shmem_write Task 15.6.10.3. shmem_read Function 15.6.10.4. shmem_display Verilog HDL Function 15.6.10.5. shmem_fill Procedure 15.6.10.6. shmem_chk_ok Function
15.6.11. BFM Log and Message Procedures x
15.6.11.1. ebfm_display Verilog HDL Function 15.6.11.2. ebfm_log_stop_sim Verilog HDL Function 15.6.11.3. ebfm_log_set_suppressed_msg_mask Task 15.6.11.4. ebfm_log_set_stop_on_msg_mask Verilog HDL Task 15.6.11.5. ebfm_log_open Verilog HDL Function 15.6.11.6. ebfm_log_close Verilog HDL Function
15.6.12. Verilog HDL Formatting Functions x
15.6.12.1. himage1 15.6.12.2. himage2 15.6.12.3. himage4 15.6.12.4. himage8 15.6.12.5. himage16 15.6.12.6. dimage1 15.6.12.7. dimage2 15.6.12.8. dimage3 15.6.12.9. dimage4 15.6.12.10. dimage5 15.6.12.11. dimage6 15.6.12.12. dimage7
15.7. Setting Up Simulation x
15.7.1. Changing Between Serial and PIPE Simulation 15.7.2. Using the PIPE Interface for Gen1 and Gen2 Variants 15.7.3. Viewing the Important PIPE Interface Signals 15.7.4. Disabling the Scrambler for Gen1 and Gen2 Simulations 15.7.5. Disabling 8B/10B Encoding and Decoding for Gen1 and Gen2 Simulations 15.7.6. Changing between the Hard and Soft Reset Controller
16. Debugging x
16.1. Hardware Bring-Up Issues 16.2. Link Training 16.3. Use Third-Party PCIe Analyzer 16.4. BIOS Enumeration Issues
16.2. Link Training x
16.2.1. Link Hangs in L0 State
C. Document Revision History x
C.1. Document Revision History of the Cyclone V Avalon® Streaming (Avalon-ST) Interface for PCIe* Solutions User Guide
1. Datasheet
2. Getting Started with the Cyclone V Hard IP for PCI Express
3. Parameter Settings
4. Interfaces and Signal Descriptions
5. Registers
6. Interrupts
7. Error Handling
8. IP Core Architecture
9. Transaction Layer Protocol (TLP) Details
10. Throughput Optimization
11. Design Implementation
12. Additional Features
13. Hard IP Reconfiguration
14. Transceiver PHY IP Reconfiguration
15. Testbench and Design Example
16. Debugging
A. Frequently Asked Questions for PCI Express
B. Lane Initialization and Reversal
C. Document Revision History

8.4. Physical Layer

The Physical Layer is the lowest level of the PCI Express protocol stack. It is the layer closest to the serial link. It encodes and transmits packets across a link and accepts and decodes received packets. The Physical Layer connects to the link through a high‑speed SERDES interface running at 2.5 Gbps for Gen1 implementations and at 2.5 or 5.0 Gbps for Gen2 implementations.

The Physical Layer is responsible for the following actions:

  • Training the link
  • Scrambling/descrambling and 8B/10B encoding/decoding for 2.5 Gbps (Gen1) and 5.0 Gbps (Gen2) per lane
  • Serializing and deserializing data
  • Operating the PIPE 3.0 Interface
  • Implementing auto speed negotiation (Gen2)
  • Transmitting and decoding the training sequence
  • Providing hardware autonomous speed control
  • Implementing auto lane reversal
Figure 40. Physical Layer Architecture

PHY Layer—The PHY layer includes the 8B/10B encode and decode functions for Gen1 and Gen2. The PHY also includes elastic buffering and serialization/deserialization functions.

The Physical Layer is subdivided by the PIPE Interface Specification into two layers (bracketed horizontally in above figure):

  • Media Access Controller (MAC) Layer—The MAC layer includes the LTSSM and the scrambling and descrambling and multilane deskew functions.
  • PHY Layer—The PHY layer includes the 8B/10B encode and decode functions for Gen1 and Gen2. The PHY also includes elastic buffering and serialization/deserialization functions.
The Physical Layer integrates both digital and analog elements. Intel designed the PIPE interface to separate the PHYMAC from the PHY. The Intel Hard IP for PCI Express complies with the PIPE interface specification.
Note: The internal PIPE interface is visible for simulation. It is not available for debugging in hardware using a logic analyzer such as Signal Tap. If you try to connect Signal Tap to this interface the design fails compilation.

The PHYMAC block comprises four main sub-blocks:

  • MAC Lane—Both the RX and the TX path use this block.
    • On the RX side, the block decodes the Physical Layer packet and reports to the LTSSM the type and number of TS1/TS2 ordered sets received.
    • On the TX side, the block multiplexes data from the DLL and the Ordered Set and SKP sub-block (LTSTX). It also adds lane specific information, including the lane number and the force PAD value when the LTSSM disables the lane during initialization.
  • LTSSM—This block implements the LTSSM and logic that tracks TX and RX training sequences on each lane.
  • For transmission, it interacts with each MAC lane sub-block and with the LTSTX sub-block by asserting both global and per-lane control bits to generate specific Physical Layer packets.
    • On the receive path, it receives the Physical Layer packets reported by each MAC lane sub-block. It also enables the multilane deskew block. This block reports the Physical Layer status to higher layers.
    • LTSTX (Ordered Set and SKP Generation)—This sub-block generates the Physical Layer packet. It receives control signals from the LTSSM block and generates Physical Layer packet for each lane. It generates the same Physical Layer Packet for all lanes and PAD symbols for the link or lane number in the corresponding TS1/TS2 fields. The block also handles the receiver detection operation to the PCS sub-layer by asserting predefined PIPE signals and waiting for the result. It also generates a SKP Ordered Set at every predefined timeslot and interacts with the TX alignment block to prevent the insertion of a SKP Ordered Set in the middle of packet.
    • Deskew—This sub-block performs the multilane deskew function and the RX alignment between the initialized lanes and the datapath. The multilane deskew implements an eight-word FIFO buffer for each lane to store symbols. Each symbol includes eight data bits, one disparity bit, and one control bit. The FIFO discards the FTS, COM, and SKP symbols and replaces PAD and IDL with D0.0 data. When all eight FIFOs contain data, a read can occur. When the multilane lane deskew block is first enabled, each FIFO begins writing after the first COM is detected. If all lanes have not detected a COM symbol after seven clock cycles, they are reset and the resynchronization process restarts, or else the RX alignment function recreates a 64-bit data word which is sent to the DLL.
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