L-Tile and H-Tile Avalon® Memory-mapped Intel® FPGA IP for PCI Express* User Guide

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ID 683667
Date 9/13/2024
Public
Document Table of Contents
Document Table of Contents x
1. Introduction 2. Quick Start Guide 3. Interface Overview 4. Parameters 5. Designing with the IP Core 6. Block Descriptions 7. Registers 8. Programming Model for the DMA Descriptor Controller 9. Programming Model for the Avalon® -MM Root Port 10. Avalon-MM Testbench and Design Example 11. Document Revision History A. PCI Express Core Architecture B. Root Port Enumeration C. Troubleshooting and Observing the Link Status
1. Introduction x
1.1. Avalon-MM Interface for PCIe 1.2. Features 1.3. Release Information 1.4. Device Family Support 1.5. Recommended Fabric Speed Grades 1.6. Performance and Resource Utilization 1.7. Transceiver Tiles 1.8. PCI Express IP Core Package Layout 1.9. Channel Availability
2. Quick Start Guide x
2.1. Design Components 2.2. Hardware and Software Requirements 2.3. Directory Structure 2.4. Generating the Design Example 2.5. Simulating the Design Example 2.6. Compiling the Design Example and Programming the Device 2.7. Installing the Linux Kernel Driver 2.8. Running the Design Example Application
3. Interface Overview x
3.1. Avalon-MM DMA Interfaces when Descriptor Controller Is Internally Instantiated 3.2. Avalon-MM DMA Interfaces when Descriptor Controller is Externally Instantiated 3.3. Other Avalon-MM Interfaces 3.4. Clocks and Reset 3.5. System Interfaces
3.3. Other Avalon-MM Interfaces x
3.3.1. Avalon-MM Master Interfaces 3.3.2. Avalon-MM Slave Interfaces 3.3.3. Control Register Access (CRA) Avalon-MM Slave
4. Parameters x
4.1. Avalon-MM Settings 4.2. Base Address Registers 4.3. Device Identification Registers 4.4. PCI Express and PCI Capabilities Parameters 4.5. Configuration, Debug and Extension Options 4.6. PHY Characteristics 4.7. Example Designs
4.4. PCI Express and PCI Capabilities Parameters x
4.4.1. Device Capabilities 4.4.2. Link Capabilities 4.4.3. MSI and MSI-X Capabilities 4.4.4. Slot Capabilities 4.4.5. Power Management 4.4.6. Vendor Specific Extended Capability (VSEC)
5. Designing with the IP Core x
5.1. Generation 5.2. Simulation 5.3. IP Core Generation Output ( Quartus® Prime Pro Edition) 5.4. Channel Layout and PLL Usage
6. Block Descriptions x
6.1. Interfaces
6.1. Interfaces x
6.1.1. Stratix® 10 DMA Avalon-MM DMA Interface to the Application Layer 6.1.2. Avalon-MM Interface to the Application Layer 6.1.3. Clocks and Reset 6.1.4. Interrupts 6.1.5. Flush Requests 6.1.6. Serial Data, PIPE, Status, Reconfiguration, and Test Interfaces
6.1.1. Stratix® 10 DMA Avalon-MM DMA Interface to the Application Layer x
6.1.1.1. Descriptor Controller Interfaces when Instantiated Internally 6.1.1.2. Write DMA Avalon-MM Master Port 6.1.1.3. Descriptor Controller Interfaces when Instantiated Externally
6.1.1.1. Descriptor Controller Interfaces when Instantiated Internally x
6.1.1.1.1. Read Data Mover 6.1.1.1.2. Read Descriptor Controller Avalon-MM Master interface 6.1.1.1.3. Write Descriptor Controller Avalon-MM Master Interface 6.1.1.1.4. Read Descriptor Table Avalon-MM Slave Interface 6.1.1.1.5. Write Descriptor Table Avalon-MM Slave Interface
6.1.1.3. Descriptor Controller Interfaces when Instantiated Externally x
6.1.1.3.1. Avalon® -ST Descriptor Source
6.1.2. Avalon-MM Interface to the Application Layer x
6.1.2.1. Bursting and Non-Bursting Avalon® -MM Module Signals 6.1.2.2. Non-Bursing Slave Module 6.1.2.3. 32-Bit Control Register Access (CRA) Slave Signals 6.1.2.4. Bursting Slave Module
6.1.3. Clocks and Reset x
6.1.3.1. Clocks 6.1.3.2. Resets
6.1.4. Interrupts x
6.1.4.1. MSI Interrupts for Endpoints 6.1.4.2. Legacy Interrupts
6.1.6. Serial Data, PIPE, Status, Reconfiguration, and Test Interfaces x
6.1.6.1. Serial Data Interface 6.1.6.2. PIPE Interface 6.1.6.3. Hard IP Status Interface 6.1.6.4. Hard IP Reconfiguration 6.1.6.5. Test Interface
7. Registers x
7.1. Configuration Space Registers 7.2. Avalon-MM DMA Bridge Registers
7.1. Configuration Space Registers x
7.1.1. Register Access Definitions 7.1.2. PCI Configuration Header Registers 7.1.3. PCI Express Capability Structures 7.1.4. Intel Defined VSEC Capability Header 7.1.5. Uncorrectable Internal Error Status Register 7.1.6. Uncorrectable Internal Error Mask Register 7.1.7. Correctable Internal Error Status Register 7.1.8. Correctable Internal Error Mask Register
7.1.4. Intel Defined VSEC Capability Header x
7.1.4.1. Intel Defined Vendor Specific Header 7.1.4.2. Intel Marker 7.1.4.3. JTAG Silicon ID 7.1.4.4. User Configurable Device and Board ID
7.2. Avalon-MM DMA Bridge Registers x
7.2.1. PCI Express Avalon-MM Bridge Register Address Map 7.2.2. DMA Descriptor Controller Registers
7.2.1. PCI Express Avalon-MM Bridge Register Address Map x
7.2.1.1. Avalon-MM to PCI Express Interrupt Status Registers 7.2.1.2. Avalon-MM to PCI Express Interrupt Enable Registers 7.2.1.3. Address Mapping for High-Performance Avalon-MM 32-Bit Slave Modules 7.2.1.4. PCI Express to Avalon-MM Interrupt Status and Enable Registers for Endpoints 7.2.1.5. PCI Express Configuration Information Registers
7.2.2. DMA Descriptor Controller Registers x
7.2.2.1. Read DMA Internal Descriptor Controller Registers 7.2.2.2. Write DMA Internal Descriptor Controller Registers
8. Programming Model for the DMA Descriptor Controller x
8.1. Read DMA Example 8.2. Write DMA Example 8.3. Software Program for Simultaneous Read and Write DMA 8.4. Read DMA and Write DMA Descriptor Format
9. Programming Model for the Avalon® -MM Root Port x
9.1. Root Port TLP Data Control and Status Registers 9.2. Sending a TLP 9.3. Receiving a Non-Posted Completion TLP 9.4. Example of Reading and Writing BAR0 Using the CRA Interface
10. Avalon-MM Testbench and Design Example x
10.1. Avalon-MM Endpoint Testbench 10.2. Endpoint Design Example 10.3. Avalon® -MM Test Driver Module 10.4. Root Port BFM 10.5. BFM Procedures and Functions
10.2. Endpoint Design Example x
10.2.1. BAR Setup
10.4. Root Port BFM x
10.4.1. Overview 10.4.2. Issuing Read and Write Transactions to the Application Layer 10.4.3. Configuration of Root Port and Endpoint 10.4.4. Configuration Space Bus and Device Numbering 10.4.5. BFM Memory Map
10.5. BFM Procedures and Functions x
10.5.1. ebfm_barwr Procedure 10.5.2. ebfm_barwr_imm Procedure 10.5.3. ebfm_barrd_wait Procedure 10.5.4. ebfm_barrd_nowt Procedure 10.5.5. ebfm_cfgwr_imm_wait Procedure 10.5.6. ebfm_cfgwr_imm_nowt Procedure 10.5.7. ebfm_cfgrd_wait Procedure 10.5.8. ebfm_cfgrd_nowt Procedure 10.5.9. BFM Configuration Procedures 10.5.10. BFM Shared Memory Access Procedures 10.5.11. BFM Log and Message Procedures 10.5.12. Verilog HDL Formatting Functions
10.5.9. BFM Configuration Procedures x
10.5.9.1. ebfm_cfg_rp_ep Procedure 10.5.9.2. ebfm_cfg_decode_bar Procedure
10.5.10. BFM Shared Memory Access Procedures x
10.5.10.1. Shared Memory Constants 10.5.10.2. shmem_write Task 10.5.10.3. shmem_read Function 10.5.10.4. shmem_display Verilog HDL Function 10.5.10.5. shmem_fill Procedure 10.5.10.6. shmem_chk_ok Function
10.5.11. BFM Log and Message Procedures x
10.5.11.1. ebfm_display Verilog HDL Function 10.5.11.2. ebfm_log_stop_sim Verilog HDL Function 10.5.11.3. ebfm_log_set_suppressed_msg_mask Task 10.5.11.4. ebfm_log_set_stop_on_msg_mask Verilog HDL Task 10.5.11.5. ebfm_log_open Verilog HDL Function 10.5.11.6. ebfm_log_close Verilog HDL Function
10.5.12. Verilog HDL Formatting Functions x
10.5.12.1. himage1 10.5.12.2. himage2 10.5.12.3. himage4 10.5.12.4. himage8 10.5.12.5. himage16 10.5.12.6. dimage1 10.5.12.7. dimage2 10.5.12.8. dimage3 10.5.12.9. dimage4 10.5.12.10. dimage5 10.5.12.11. dimage6 10.5.12.12. dimage7
11. Document Revision History x
11.1. Document Revision History for the L-Tile and H-Tile Avalon® Memory-mapped Intel® FPGA IP for PCI Express* User Guide
A. PCI Express Core Architecture x
A.1. Transaction Layer A.2. Data Link Layer A.3. Physical Layer
C. Troubleshooting and Observing the Link Status x
C.1. Troubleshooting C.2. PCIe Link Inspector Overview
C.1. Troubleshooting x
C.1.1. Simulation Fails To Progress Beyond Polling.Active State C.1.2. Hardware Bring-Up Issues C.1.3. Link Training C.1.4. Use Third-Party PCIe Analyzer
C.2. PCIe Link Inspector Overview x
C.2.1. PCIe* Link Inspector Hardware
C.2.1. PCIe* Link Inspector Hardware x
C.2.1.1. Enabling the PCIe* Link Inspector C.2.1.2. Launching the PCIe* Link Inspector C.2.1.3. The PCIe* Link Inspector LTSSM Monitor C.2.1.4. Accessing the Configuration Space and Transceiver Registers C.2.1.5. Additional Status Commands
C.2.1.3. The PCIe* Link Inspector LTSSM Monitor x
C.2.1.3.1. LTSSM Monitor Registers C.2.1.3.2. ltssm_save2file <file_name> C.2.1.3.3. ltssm_file2console C.2.1.3.4. ltssm_debug_check C.2.1.3.5. ltssm_display <num_states> C.2.1.3.6. ltssm_save_oldstates
C.2.1.4. Accessing the Configuration Space and Transceiver Registers x
C.2.1.4.1. PCIe* Link Inspector Commands C.2.1.4.2. NPDME PLL and Channel Commands C.2.1.4.3. Register Address Map
C.2.1.5. Additional Status Commands x
C.2.1.5.1. Displaying PLL Lock and Calibration Status Registers
1. Introduction
2. Quick Start Guide
3. Interface Overview
4. Parameters
5. Designing with the IP Core
6. Block Descriptions
7. Registers
8. Programming Model for the DMA Descriptor Controller
9. Programming Model for the Avalon® -MM Root Port
10. Avalon-MM Testbench and Design Example
11. Document Revision History
A. PCI Express Core Architecture
B. Root Port Enumeration
C. Troubleshooting and Observing the Link Status

A.3. 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, at 2.5 or 5.0 Gbps for Gen2 implementations, and at 2.5, 5.0 or 8.0 Gbps for Gen3 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), 5.0 Gbps (Gen2), or 128b/130b encoding/decoding of 8.0 Gbps (Gen3) per lane
  • Serializing and deserializing data
  • Equalization (Gen3)
  • Operating the PIPE 3.0 Interface
  • Implementing auto speed negotiation (Gen2 and Gen3)
  • Transmitting and decoding the training sequence
  • Providing hardware autonomous speed control
  • Implementing auto lane reversal

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

  • PHYMAC—The MAC layer includes the LTSSM and the scrambling/descrambling. byte reordering, and multilane deskew functions.
  • PHY Layer—The PHY layer includes the 8B/10B encode and decode functions for Gen1 and Gen2. It includes 128b/130b encode and decode functions for Gen3. 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.
Figure 76. Physical Layer Architecture

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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