Low Latency Ethernet 10G MAC IP User Guide: Agilex™ 3 and Agilex™ 5 FPGAs and SoCs

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ID 813663
Date 9/01/2025
Public
Document Table of Contents
Document Table of Contents x
1. Low Latency Ethernet 10G MAC IP Overview 2. Getting Started 3. Functional Description 4. Parameter Settings for the Low Latency Ethernet 10G MAC IP Core 5. Interface Signals 6. Configuration Registers 7. Debug Checklist 8. Low Latency Ethernet 10G MAC IP User Guide: Agilex™ 3 and Agilex™ 5 FPGAs and SoCs Archives 9. Document Revision History for the Low Latency Ethernet 10G MAC IP User Guide: Agilex™ 3 and Agilex™ 5 FPGAs and SoCs
1. Low Latency Ethernet 10G MAC IP Overview x
1.1. Features 1.2. Release Information 1.3. Low Latency Ethernet 10G MAC Operating Modes 1.4. Device Family Support 1.5. Performance and Resource Utilization
1.5. Performance and Resource Utilization x
1.5.1. Resource Utilization 1.5.2. TX and RX Latency
2. Getting Started x
2.1. Introduction to Altera IP Cores 2.2. Installing and Licensing IP Cores 2.3. Specifying the IP Parameters and Options ( Quartus® Prime Pro Edition) 2.4. Generated File Structure 2.5. Simulating IP Cores 2.6. Upgrading the Low Latency Ethernet 10G MAC IP Core 2.7. Low Latency Ethernet 10G MAC IP Design Examples
2.6. Upgrading the Low Latency Ethernet 10G MAC IP Core x
2.6.1. Design Considerations
2.6.1. Design Considerations x
2.6.1.1. Timing Constraints
2.6.1.1. Timing Constraints x
2.6.1.1.1. Pseudo-Static CSR Fields 2.6.1.1.2. Clock Crosser 2.6.1.1.3. Dual Clock FIFO
2.7. Low Latency Ethernet 10G MAC IP Design Examples x
2.7.1. Low Latency Ethernet 10G MAC IP Design Example for Agilex™ 3 and Agilex™ 5 Devices
3. Functional Description x
3.1. Architecture 3.2. Interfaces 3.3. Frame Types 3.4. TX Datapath 3.5. RX Datapath 3.6. Flow Control 3.7. Reset Requirements 3.8. XGMII Error Handling (Link Fault) 3.9. IEEE 1588v2
3.4. TX Datapath x
3.4.1. Padding Bytes Insertion 3.4.2. Address Insertion 3.4.3. CRC-32 Insertion 3.4.4. XGMII Encapsulation 3.4.5. Inter-Packet Gap Generation and Insertion 3.4.6. XGMII Transmission 3.4.7. Unidirectional Feature 3.4.8. TX Promiscuous (Transparent) Mode 3.4.9. TX Timing Diagrams
3.5. RX Datapath x
3.5.1. XGMII Decapsulation 3.5.2. CRC Checking 3.5.3. Address Checking 3.5.4. Frame Type Checking 3.5.5. Length Checking 3.5.6. CRC and Padding Bytes Removal 3.5.7. Overflow Handling 3.5.8. RX Promiscuous (Transparent) Mode 3.5.9. RX Timing Diagrams
3.5.5. Length Checking x
3.5.5.1. Frame Length 3.5.5.2. Payload Length
3.6. Flow Control x
3.6.1. IEEE 802.3 Flow Control 3.6.2. Priority-Based Flow Control
3.6.1. IEEE 802.3 Flow Control x
3.6.1.1. Pause Frame Reception 3.6.1.2. Pause Frame Transmission
3.6.2. Priority-Based Flow Control x
3.6.2.1. PFC Frame Reception 3.6.2.2. PFC Frame Transmission
3.9. IEEE 1588v2 x
3.9.1. Architecture 3.9.2. TX Datapath 3.9.3. RX Datapath 3.9.4. Frame Format
3.9.4. Frame Format x
3.9.4.1. PTP Packet in IEEE 802.3 3.9.4.2. PTP Packet over UDP/IPv4 3.9.4.3. PTP Packet over UDP/IPv6
5. Interface Signals x
5.1. Clock and Reset Signals 5.2. Speed Selection Signal 5.3. Error Correction Signals 5.4. Unidirectional Signals 5.5. Avalon® Memory-Mapped Interface Programming Signals 5.6. Avalon® Streaming Data Interfaces 5.7. Avalon® Streaming Flow Control Signals 5.8. Avalon® Streaming Status Interface 5.9. PHY-side Interfaces 5.10. IEEE 1588v2 Interfaces
5.6. Avalon® Streaming Data Interfaces x
5.6.1. Avalon® Streaming TX Data Interface Signals 5.6.2. Avalon® Streaming RX Data Interface Signals 5.6.3. Avalon® Streaming Data Interface Clocks
5.8. Avalon® Streaming Status Interface x
5.8.1. Avalon® Streaming Interface TX Status Signals 5.8.2. Avalon® Streaming Interface RX Status Signals
5.9. PHY-side Interfaces x
5.9.1. XGMII TX Signals 5.9.2. XGMII RX Signals 5.9.3. GMII TX Signals 5.9.4. GMII RX Signals 5.9.5. MII TX Signals 5.9.6. MII RX Signals
5.10. IEEE 1588v2 Interfaces x
5.10.1. IEEE 1588v2 Egress TX Signals 5.10.2. IEEE 1588v2 Ingress RX Signals 5.10.3. IEEE 1588v2 Interface Clocks
6. Configuration Registers x
6.1. Register Map 6.2. Register Access Definition 6.3. Primary MAC Address 6.4. MAC Reset Control Register 6.5. TX Configuration and Status Registers 6.6. Flow Control Registers 6.7. Unidirectional Control Registers 6.8. RX Configuration and Status Registers 6.9. ECC Registers 6.10. Statistics Registers 6.11. Timestamp Registers
6.11. Timestamp Registers x
6.11.1. Calculating PHY Total Latency 6.11.2. Calculating Deterministic Latency 6.11.3. PTP Register Configuration
7. Debug Checklist x
7.1. Pre-Debugging Process 7.2. Clock Frequency 7.3. Recommended Reset Handling 7.4. Recommended Signals for Signal Tap
1. Low Latency Ethernet 10G MAC IP Overview
2. Getting Started
3. Functional Description
4. Parameter Settings for the Low Latency Ethernet 10G MAC IP Core
5. Interface Signals
6. Configuration Registers
7. Debug Checklist
8. Low Latency Ethernet 10G MAC IP User Guide: Agilex™ 3 and Agilex™ 5 FPGAs and SoCs Archives
9. Document Revision History for the Low Latency Ethernet 10G MAC IP User Guide: Agilex™ 3 and Agilex™ 5 FPGAs and SoCs

3.6.1.2. Pause Frame Transmission

Use one of the following methods to trigger pause frame transmission:

  • avalon_st_pause_data signal (tx_pauseframe_enable[2:1] set to 0)—You can connect this 2-bit signal to a FIFO buffer or a client. Bit setting:
    • avalon_st_pause_data[1]: 1—triggers the transmission of XOFF pause frames.
    • avalon_st_pause_data[0]: 1—triggers the transmission of XON pause frames. The transmission of XON pause frames only trigger for one time after XOFF pause frames regardless of how long the avalon_st_pause_data[0] signal is asserted.
    If pause frame transmission is triggered when the MAC is generating a pause frame, the MAC ignores the incoming request and completes the generation of the pause frame. Upon completion, if the avalon_st_pause_data signal remains asserted, the MAC generates a new pause frame and continues to do so until the signal is deasserted. You can also configure the gap between successive XOFF requests for using the tx_pauseframe_quanta register. XON pause frames will only be generated if the MAC generates XOFF pause frames.
  • tx_pauseframe_control register (tx_pauseframe_enable[2:0] set to 0x1)—A host (software) can set this register to trigger pause frames transmission. Setting tx_pauseframe_control[1] to 1 triggers the transmission of XOFF pause frames; setting tx_pauseframe_control[0] to 1 triggers the transmission of XON pause frames. The register clears itself after the request is executed.

You can configure the pause quanta in the tx_pauseframe_quanta register. The MAC sets the pause quanta field in XOFF pause frames to this register value.

Note: The new register field determines which pause interface takes effect.

The following figure shows the transmission of an XON pause frame. The MAC sets the destination address field to the global multicast address, 01-80-C2-00-00-01 (0x010000c28001) and the source address to the MAC primary address configured in the tx_addrins_macaddr0 and tx_addrins_madaddr1 registers.

Figure 23. XON Pause Frame Transmission
Level Two Title