Low Latency 40G Ethernet IP User Guide: Agilex™ 5 FPGAs and SoCs

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ID 813652
Date 10/24/2025
Public
Document Table of Contents
Document Table of Contents x
1. About the Low Latency 40G Ethernet IP 2. Low Latency 40G Ethernet IP Parameters 3. Getting Started 4. Functional Description 5. Clocking and Reset Requirements 6. Interfaces and Signal Descriptions 7. Control, Status, and Statistics Register Descriptions 8. Comparison Between Various Low Latency 40G Ethernet IPs 9. Document Revision History for the Low Latency 40G Ethernet IP User Guide: Agilex™ 5 FPGAs and SoCs
1. About the Low Latency 40G Ethernet IP x
1.1. Low Latency 40G Ethernet IP Supported Features 1.2. Low Latency 40G Ethernet IP Device Family and Speed Grade Support 1.3. Resource Utilization 1.4. Release Information
1.2. Low Latency 40G Ethernet IP Device Family and Speed Grade Support x
1.2.1. Low Latency 40G Ethernet Device Family Support 1.2.2. Low Latency 40G Ethernet IP Device Speed Grade Support
3. Getting Started x
3.1. Introduction to Altera IP 3.2. Installing and Licensing IPs 3.3. Specifying the IP Parameters and Options 3.4. Simulating the IP 3.5. Generated File Structure 3.6. Integrating Your IP in Your Design 3.7. Testbench 3.8. Compiling the Full Design and Programming the FPGA
3.6. Integrating Your IP in Your Design x
3.6.1. Pin Assignments 3.6.2. Placement Settings
3.7. Testbench x
3.7.1. Understanding the Testbench Behavior
4. Functional Description x
4.1. Low Latency 40G Ethernet IP Functional Description 4.2. GTS Transceiver Configuration 4.3. Transmitter Datapath 4.4. Receiver Datapath 4.5. Flow Control 4.6. Link Fault Signaling Interface
4.3. Transmitter Datapath x
4.3.1. Transmitter MAC 4.3.2. Transmitter PCS 4.3.3. PMA
4.3.1. Transmitter MAC x
4.3.1.1. Preamble Insertion 4.3.1.2. Frame Padding 4.3.1.3. Inter-Packet Gap Generation and Insertion 4.3.1.4. Frame Check Sequence (CRC-32) Insertion 4.3.1.5. Transmitter Avalon® Streaming Filter
4.4. Receiver Datapath x
4.4.1. Receiver MAC 4.4.2. Receiver PCS
4.4.1. Receiver MAC x
4.4.1.1. IP Core Preamble Processing 4.4.1.2. IP Core CRC Checking and Dynamic Forwarding 4.4.1.3. IP Core Strict SFD Checking 4.4.1.4. Length/Type Field Processing
4.4.1.4. Length/Type Field Processing x
4.4.1.4.1. Frame Type Checking 4.4.1.4.2. Length Checking
4.5. Flow Control x
4.5.1. Transmitter Pause/PFC Flow Control Transmission 4.5.2. XON/XOFF Pause Frames
5. Clocking and Reset Requirements x
5.1. Clocks 5.2. Reset Requirements
6. Interfaces and Signal Descriptions x
6.1. Transmitter MAC Interface to User Logic 6.2. Receiver MAC Interface to User Logic 6.3. Transmitter PCS Interface to User Logic 6.4. Receiver PCS Interface to User Logic 6.5. GTS Transceivers Signals 6.6. GTS Transceiver Reconfiguration Signals 6.7. Avalon® Memory-Mapped Management Interface 6.8. Miscellaneous Status and Debug Signals 6.9. Reset Signals 6.10. Clocks 6.11. Flow Control Interface 6.12. GTS Reset Sequencer IP
7. Control, Status, and Statistics Register Descriptions x
7.1. PHY Registers 7.2. Transmitter MAC Registers 7.3. Receiver MAC Registers 7.4. Pause/PFC Flow Control 7.5. Statistics Counters 7.6. Shadow Register
1. About the Low Latency 40G Ethernet IP
2. Low Latency 40G Ethernet IP Parameters
3. Getting Started
4. Functional Description
5. Clocking and Reset Requirements
6. Interfaces and Signal Descriptions
7. Control, Status, and Statistics Register Descriptions
8. Comparison Between Various Low Latency 40G Ethernet IPs
9. Document Revision History for the Low Latency 40G Ethernet IP User Guide: Agilex™ 5 FPGAs and SoCs

4.1. Low Latency 40G Ethernet IP Functional Description

The Low Latency 40G Ethernet IP for Agilex™ 5 devices implements an Ethernet MAC in accordance with the IEEE 802.3 Ethernet Standard.

This section describes the Low Latency 40G Ethernet IP using Agilex™ 5 devices with GTS transceiver.
Figure 6.  Low Latency 40G Ethernet IP Block Diagram
The Low Latency 40G Ethernet IP supports the below variants:
  • MAC, PCS, and PMA mode: The Low Latency 40G Ethernet MAC is instantiated inside the IP along with the Soft PCS and the Hard PMA blocks. Provides the 128-bit (312.5 MHz) Avalon® streaming interface towards the client and XLAUI (4 lanes at 10.3125 Gbps) interface towards the network.
  • PCS and PMA mode: The Soft PCS and the Hard PMA is part of the IP, and the Low Latency 40G Ethernet MAC block are not instantiated inside the IP. Provides the 128-bit (312.5 MHz clock) XLGMII interface towards the client and XLAUI (4 lanes at 10.3125 Gbps) interface towards the network.

The IP supports either the Avalon® streaming interface or the XLGMII interface towards the client side based on the variant selected at GUI while generating the IP. You cannot switch the variant at runtime. In PCS and PMA mode, the MAC related CSR’s and parameters are not valid. The IP does not support the KR4, backplane feature.

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