Low Latency 40- and 100-Gbps Ethernet MAC and PHY MegaCore Function User Guide

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ID 683628
Date 12/28/2017
Public
Document Table of Contents
Document Table of Contents x
1. About the Low Latency 40- and 100-Gbps Ethernet MAC and PHY IP Core 2. Getting Started 3. Functional Description 4. Debugging the Link A. Arria 10 10GBASE-KR Registers B. Differences Between Low Latency 40-100GbE IP Core and 40-100GbE IP Core v15.1 C. Additional Information
1. About the Low Latency 40- and 100-Gbps Ethernet MAC and PHY IP Core x
1.1. Low Latency 40- and 100-Gbps Ethernet MAC and PHY IP Core Supported Features 1.2. Low Latency 40-100GbE IP Core Device Family and Speed Grade Support 1.3. IP Core Verification 1.4. Performance and Resource Utilization 1.5. Release Information
1.2. Low Latency 40-100GbE IP Core Device Family and Speed Grade Support x
1.2.1. Device Family Support 1.2.2. Low Latency 40-100GbE IP Core Device Speed Grade Support
1.3. IP Core Verification x
1.3.1. Simulation Environment 1.3.2. Compilation Checking 1.3.3. Hardware Testing
1.4. Performance and Resource Utilization x
1.4.1. Stratix V Resource Utilization for Low Latency 40-100GbE IP Cores 1.4.2. Arria 10 Resource Utilization for Low Latency 40-100GbE IP Cores
2. Getting Started x
2.1. Installation and Licensing for LL 40-100GbE IP Core for Stratix V Devices 2.2. Licensing IP Cores 2.3. Specifying the Low Latency 40-100GbE IP Core Parameters and Options 2.4. IP Core Parameters 2.5. Files Generated for Stratix V Variations 2.6. Files Generated for Arria 10 Variations 2.7. Integrating Your IP Core in Your Design 2.8. Low Latency 40-100GbE IP Core Testbenches 2.9. Simulating the Low Latency 40‑100GbE IP Core With the Testbenches 2.10. Compiling the Full Design and Programming the FPGA 2.11. Initializing the IP Core
2.2. Licensing IP Cores x
2.2.1. OpenCore Plus IP Evaluation
2.7. Integrating Your IP Core in Your Design x
2.7.1. Pin Assignments 2.7.2. External Transceiver Reconfiguration Controller Required in Stratix V Designs 2.7.3. Transceiver PLL Required in Arria 10 Designs 2.7.4. External Time-of-Day Module for Variations with 1588 PTP Feature 2.7.5. Clock Requirements for 40GBASE-KR4 Variations 2.7.6. External TX MAC PLL 2.7.7. Placement Settings for the Low Latency 40-100GbE IP Core
2.8. Low Latency 40-100GbE IP Core Testbenches x
2.8.1. Low Latency 40-100GbE IP Core Testbench Overview 2.8.2. Understanding the Testbench Behavior
2.9. Simulating the Low Latency 40‑100GbE IP Core With the Testbenches x
2.9.1. Generating the Low Latency 40-100GbE Testbench 2.9.2. Optimizing the Low Latency 40‑100GbE IP Core Simulation With the Testbenches 2.9.3. Simulating with the Modelsim Simulator 2.9.4. Simulating with the NCSim Simulator 2.9.5. Simulating with the VCS Simulator 2.9.6. Testbench Output Example: Low Latency 40-100GbE IP Core
3. Functional Description x
3.1. High Level System Overview 3.2. Low Latency 40-100GbE MAC and PHY Functional Description 3.3. Signals 3.4. Software Interface: Registers 3.5. Ethernet Glossary
3.2. Low Latency 40-100GbE MAC and PHY Functional Description x
3.2.1. Low Latency 40-100GbE IP Core TX Datapath 3.2.2. Low Latency 40-100GbE IP Core TX Data Bus Interfaces 3.2.3. Low Latency 40-100GbE IP Core RX Datapath 3.2.4. Low Latency 40-100GbE IP Core RX Data Bus Interface 3.2.5. Low Latency 100GbE CAUI–4 PHY 3.2.6. External Reconfiguration Controller 3.2.7. External Transceiver PLL 3.2.8. External TX MAC PLL 3.2.9. Congestion and Flow Control Using Pause Frames 3.2.10. Pause Control and Generation Interface 3.2.11. Pause Control Frame Filtering 3.2.12. Link Fault Signaling Interface 3.2.13. Statistics Counters Interface 3.2.14. 1588 Precision Time Protocol Interfaces 3.2.15. PHY Status Interface 3.2.16. Transceiver PHY Serial Data Interface 3.2.17. Low Latency 40GBASE-KR4 IP Core Variations 3.2.18. Control and Status Interface 3.2.19. Arria 10 Transceiver Reconfiguration Interface 3.2.20. Clocks 3.2.21. Resets
3.2.1. Low Latency 40-100GbE IP Core TX Datapath x
3.2.1.1. Preamble, Start, and SFD Insertion 3.2.1.2. Address Insertion 3.2.1.3. Length/Type Field Processing 3.2.1.4. Frame Padding 3.2.1.5. Frame Check Sequence (CRC-32) Insertion 3.2.1.6. Inter‑Packet Gap Generation and Insertion 3.2.1.7. Error Insertion Test and Debug Feature
3.2.2. Low Latency 40-100GbE IP Core TX Data Bus Interfaces x
3.2.2.1. Low Latency 40-100GbE IP Core User Interface Data Bus 3.2.2.2. Low Latency 40-100GbE IP Core TX Data Bus with Adapters (Avalon-ST Interface) 3.2.2.3. Low Latency 40-100GbE IP Core TX Data Bus Without Adapters (Custom Streaming Interface) 3.2.2.4. Bus Quantization Effects With Adapters 3.2.2.5. User Interface to Ethernet Transmission
3.2.2.5. User Interface to Ethernet Transmission x
3.2.2.5.1. Order of Transmission
3.2.3. Low Latency 40-100GbE IP Core RX Datapath x
3.2.3.1. Low Latency 40-100GbE IP Core RX Filtering 3.2.3.2. 40-100GbE IP Core Preamble Processing 3.2.3.3. 40-100GbE IP Core FCS (CRC-32) Removal 3.2.3.4. 40-100GbE IP Core CRC Checking 3.2.3.5. LL 40-100GbE IP Core Malformed Packet Handling 3.2.3.6. RX CRC Forwarding 3.2.3.7. Inter-Packet Gap 3.2.3.8. Pause Ignore 3.2.3.9. Control Frame Identification
3.2.4. Low Latency 40-100GbE IP Core RX Data Bus Interface x
3.2.4.1. Low Latency 40-100GbE IP Core User Interface Data Bus 3.2.4.2. Low Latency 40-100GbE IP Core RX Data Bus 3.2.4.3. Low Latency 40-100GbE IP Core RX Data Bus Without Adapters (Custom Streaming Interface)
3.2.9. Congestion and Flow Control Using Pause Frames x
3.2.9.1. Conditions Triggering XOFF Frame Transmission 3.2.9.2. Conditions Triggering XON Frame Transmission
3.2.13. Statistics Counters Interface x
3.2.13.1. OctetOK Count Interface
3.2.14. 1588 Precision Time Protocol Interfaces x
3.2.14.1. Implementing a 1588 System That Includes a LL 40-100GbE IP Core 3.2.14.2. PTP Receive Functionality 3.2.14.3. PTP Transmit Functionality 3.2.14.4. External Time-of-Day Module for 1588 PTP Variations 3.2.14.5. PTP Timestamp and TOD Formats 3.2.14.6. 1588 PTP Interface Signals
3.3. Signals x
3.3.1. Low Latency 40-100GbE IP Core Signals
3.4. Software Interface: Registers x
3.4.1. Low Latency 40-100GbE IP Core Registers 3.4.2. LL 40‑100GbE Hardware Design Example Registers
3.4.1. Low Latency 40-100GbE IP Core Registers x
3.4.1.1. PHY Registers 3.4.1.2. Link Fault Signaling Registers 3.4.1.3. LL 40GBASE-KR4 Registers 3.4.1.4. Low Latency 40-100GbE IP Core MAC Configuration Registers 3.4.1.5. Pause Registers 3.4.1.6. TX Statistics Registers 3.4.1.7. RX Statistics Registers 3.4.1.8. 1588 PTP Registers
3.4.2. LL 40‑100GbE Hardware Design Example Registers x
3.4.2.1. Packet Client Registers
4. Debugging the Link x
4.1. Creating a SignalTap II Debug File to Match Your Design Hierarchy
A. Arria 10 10GBASE-KR Registers x
A.1. 10GBASE-KR PHY Register Definitions
C. Additional Information x
C.1. Low Latency 40- and 100-Gbps Ethernet MAC and PHY MegaCore Function User Guide Archives C.2. Low Latency 40- and 100-Gbps Ethernet MAC and PHY MegaCore Function User Guide Revision History C.3. How to Contact Altera C.4. Typographic Conventions
1. About the Low Latency 40- and 100-Gbps Ethernet MAC and PHY IP Core
2. Getting Started
3. Functional Description
4. Debugging the Link
A. Arria 10 10GBASE-KR Registers
B. Differences Between Low Latency 40-100GbE IP Core and 40-100GbE IP Core v15.1
C. Additional Information

3.2.2.4. Bus Quantization Effects With Adapters

The TX custom streaming interface allows a packet to start at any of two or four positions to maximize utilization of the link bandwidth. The TX Avalon-ST interface only allows start of packet (SOP) to be placed at the most significant position. If the SOP were restricted to the most significant position in the client logic data bus in the custom streaming interface, bus bandwidth would be reduced.

Figure 16. Reduced Bandwidth With Left-Aligned SOP Requirement Illustrates the reduction of bandwidth that would be caused by left‑aligning the SOP for the 100GbE IP core.

The example shows a nine-word packet, which is the worst case for bandwidth utilization. Assuming another packet is waiting for transmission, the effective ingress bandwidth is reduced by 25%. Running the MAC portion of the logic slightly faster than is required can mitigate this loss of bandwidth. Additional increases in the MAC frequency can provide further mitigation, although increases in frequency make timing closure more difficult. The wider data bus for the Avalon-ST interface also helps to compensate for the Avalon-ST left‑aligned SOP requirement.

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