Low Latency Ethernet 10G MAC IP User Guide: Agilex™ 3 and Agilex™ 5 FPGAs and SoCs
ID
813663
Date
9/01/2025
Public
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
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
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
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
3.4.7. Unidirectional Feature
The MAC TX implements the unidirectional feature as specified by clause 66 in the IEEE802.3 specification. This is an optional feature supported only in 10G, 1G/10G, and 1G/2.5G/10G core variants. When you enable this feature, output ports—unidirectional_en, unidirectional_remote_fault_dis— and register fields—UniDir_En (Bit 0), UniDirRmtFault_Dis (Bit 1)— are accessible to control the TX XGMII interface.
Bit 0 Register Field | Bit 1 Register Field | Link Status | TX XGMII Interface Behavior |
---|---|---|---|
Don't care | Don't care | No link fault | Continue to allow normal packet transmission. |
0 | Don't care | Local fault | Immediately override the current content with remote fault sequence. |
1 | 0 | Local fault | Continue to send packet if there is one. Otherwise, override the IPG/IDLE bytes with remote fault sequence.1 |
1 | 1 | Local fault | Continue to allow normal packet transmission (similar to no link fault). |
0 | Don't care | Remote fault | Immediately override the current content with IDLE control characters. |
1 | Don't care | Remote fault | Continue to allow normal packet transmission (similar to no link fault). |
1 At least a full column of IDLE (four IDLE characters) must precede the remote fault sequence.