Cyclone® V Avalon® Memory-Mapped (Avalon-MM) Interface for PCI Express* Solutions User Guide

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ID 683494
Date 10/24/2024
Public
Document Table of Contents
Document Table of Contents x
1. Datasheet 2. Getting Started with the Avalon-MM Cyclone V Hard IP for PCI Express 3. Parameter Settings 4. Interfaces and Signal Descriptions 5. Registers 6. Reset and Clocks 7. Interrupts for Endpoints 8. Error Handling A. PCI Express Protocol Stack 9. Design Implementation 10. Additional Features 11. Transceiver PHY IP Reconfiguration 12. Debugging B. Frequently Asked Questions for PCI Express C. Lane Initialization and Reversal D. Document Revision History
1. Datasheet x
1.1. Avalon-MM 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. IP Core Verification 1.8. Performance and Resource Utilization 1.9. Recommended Speed Grades 1.10. Creating a Design for PCI Express
1.7. IP Core Verification x
1.7.1. Compatibility Testing Environment
2. Getting Started with the Avalon-MM Cyclone V Hard IP for PCI Express x
2.1. Running Platform Designer 2.2. Generating the Example Design 2.3. Running a Gate-Level Simulation 2.4. Simulating the Single DWord Design 2.5. Understanding Channel Placement Guidelines 2.6. Generating Synthesis Files 2.7. Compiling the Design in the Quartus® Prime Software 2.8. Programming a Device
3. Parameter Settings x
3.1. Avalon-MM System Settings 3.2. Base Address Register (BAR) Settings 3.3. Device Identification Registers 3.4. Device Capabilities 3.5. Error Reporting 3.6. Link Capabilities 3.7. MSI and MSI-X Capabilities 3.8. Power Management 3.9. Avalon Memory‑Mapped System Settings
4. Interfaces and Signal Descriptions x
4.1. 64- or 128-Bit Avalon-MM Interface to the Endpoint Application Layer 4.2. Clock Signals 4.3. Reset Signals 4.4. Hard IP Status 4.5. Interrupts for Endpoints when Multiple MSI/MSI-X Support Is Enabled 4.6. Physical Layer Interface Signals
4.1. 64- or 128-Bit Avalon-MM Interface to the Endpoint Application Layer x
4.1.1. 32-Bit Non-Bursting Avalon-MM Control Register Access (CRA) Slave Signals 4.1.2. Bursting and Non-Bursting Avalon® -MM Module Signals 4.1.3. 64- or 128-Bit Bursting TX Avalon-MM Slave Signals
4.6. Physical Layer Interface Signals x
4.6.1. Transceiver Reconfiguration 4.6.2. Hard IP Status Extension 4.6.3. Serial Interface Signals 4.6.4. PIPE Interface Signals 4.6.5. Test Signals
4.6.2. Hard IP Status Extension x
4.6.2.1. Configuration Space Register Access 4.6.2.2. Configuration Space Register Access Timing
4.6.3. Serial Interface Signals x
4.6.3.1. Physical Layout of Hard IP in Cyclone V Devices 4.6.3.2. 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. CvP Registers 5.7. 64- or 128-Bit Avalon-MM Bridge Register Descriptions 5.8. Programming Model for Avalon-MM Root Port 5.9. Uncorrectable Internal Error Mask Register 5.10. Uncorrectable Internal Error Status Register 5.11. Correctable Internal Error Mask Register 5.12. Correctable Internal Error Status Register
5.7. 64- or 128-Bit Avalon-MM Bridge Register Descriptions x
5.7.1. Avalon-MM to PCI Express Interrupt Registers
5.7.1. Avalon-MM to PCI Express Interrupt Registers x
5.7.1.1. Avalon-MM to PCI Express Interrupt Status Registers 5.7.1.2. Avalon-MM to PCI Express Interrupt Enable Registers 5.7.1.3. PCI Express Mailbox Registers 5.7.1.4. Avalon-MM-to-PCI Express Address Translation Table 5.7.1.5. PCI Express to Avalon-MM Interrupt Status and Enable Registers for Endpoints 5.7.1.6. Avalon-MM Mailbox Registers 5.7.1.7. Control Register Access (CRA) Avalon-MM Slave Port
5.8. Programming Model for Avalon-MM Root Port x
5.8.1. Sending a Write TLP 5.8.2. Sending a Read TLP or Receiving a Non-Posted Completion TLP 5.8.3. Examples of Reading and Writing BAR0 Using the CRA Interface 5.8.4. PCI Express to Avalon-MM Interrupt Status and Enable Registers for Root Ports 5.8.5. Root Port TLP Data Registers
6. Reset and Clocks x
6.1. Reset Sequence for Hard IP for PCI Express IP Core and Application Layer 6.2. Clocks
6.2. Clocks x
6.2.1. Clock Domains 6.2.2. Clock Summary
6.2.1. Clock Domains x
6.2.1.1. pclk 6.2.1.2. coreclkout_hip 6.2.1.3. pld_clk
7. Interrupts for Endpoints x
7.1. Enabling MSI or Legacy Interrupts 7.2. Generation of Avalon-MM Interrupts 7.3. Interrupts for Endpoints Using the Avalon-MM Interface with Multiple MSI/MSI-X Support
8. Error Handling x
8.1. Physical Layer Errors 8.2. Data Link Layer Errors 8.3. Transaction Layer Errors 8.4. Error Reporting and Data Poisoning 8.5. Uncorrectable and Correctable Error Status Bits
A. PCI Express Protocol Stack x
A.1. Top-Level Interfaces A.2. Data Link Layer A.3. Physical Layer A.4. 32-Bit PCI Express Avalon-MM Bridge A.5. Completer Only Single Dword Endpoint
A.1. Top-Level Interfaces x
A.1.1. Avalon-MM Interface A.1.2. Clocks and Reset A.1.3. Transceiver Reconfiguration A.1.4. Interrupts A.1.5. PIPE
A.4. 32-Bit PCI Express Avalon-MM Bridge x
A.4.1. Avalon‑MM Bridge TLPs A.4.2. Avalon-MM-to-PCI Express Write Requests A.4.3. Avalon-MM-to-PCI Express Upstream Read Requests A.4.4. PCI Express-to-Avalon-MM Read Completions A.4.5. PCI Express-to-Avalon-MM Downstream Write Requests A.4.6. PCI Express-to-Avalon-MM Downstream Read Requests A.4.7. Avalon-MM-to-PCI Express Read Completions A.4.8. PCI Express-to-Avalon-MM Address Translation for 32-Bit Bridge A.4.9. Minimizing BAR Sizes and the PCIe Address Space A.4.10. Avalon® -MM-to-PCI Express Address Translation Algorithm for 32-Bit Addressing
A.5. Completer Only Single Dword Endpoint x
A.5.1. RX Block A.5.2. Avalon-MM RX Master Block A.5.3. TX Block A.5.4. Interrupt Handler Block
9. Design Implementation x
9.1. Making Analog QSF Assignments Using the Assignment Editor 9.2. Making Pin Assignments 9.3. Recommended Reset Sequence to Avoid Link Training Issues
10. Additional Features x
10.1. Configuration over Protocol (CvP) 10.2. Autonomous Mode 10.3. ECRC
10.2. Autonomous Mode x
10.2.1. Enabling Autonomous Mode 10.2.2. Enabling CvP Initialization
10.3. ECRC x
10.3.1. ECRC on the RX Path 10.3.2. ECRC on the TX Path
11. Transceiver PHY IP Reconfiguration x
11.1. Connecting the Transceiver Reconfiguration Controller IP Core 11.2. Transceiver Reconfiguration Controller Connectivity for Designs Using CvP
12. Debugging x
12.1. Hardware Bring-Up Issues 12.2. Link Training 12.3. Use Third-Party PCIe Analyzer 12.4. BIOS Enumeration Issues
D. Document Revision History x
D.1. Arria® V and Cyclone® V Avalon® Memory Mapped (Avalon-MM) Interface for PCIe* Solutions User Guide Revision History
1. Datasheet
2. Getting Started with the Avalon-MM Cyclone V Hard IP for PCI Express
3. Parameter Settings
4. Interfaces and Signal Descriptions
5. Registers
6. Reset and Clocks
7. Interrupts for Endpoints
8. Error Handling
A. PCI Express Protocol Stack
9. Design Implementation
10. Additional Features
11. Transceiver PHY IP Reconfiguration
12. Debugging
B. Frequently Asked Questions for PCI Express
C. Lane Initialization and Reversal
D. Document Revision History

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 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 36. 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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