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

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ID 813652
Date 11/25/2024
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Document Table of Contents
Document Table of Contents x
1. About the Low Latency 40G Ethernet Intel® FPGA IP 2. Low Latency 40G Ethernet Intel® FPGA 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 Intel® FPGA IPs 9. Document Revision History for the Low Latency 40G Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs
1. About the Low Latency 40G Ethernet Intel® FPGA IP x
1.1. Low Latency 40G Ethernet Intel® FPGA IP Supported Features 1.2. Low Latency 40G Ethernet Intel® FPGA IP Device Family and Speed Grade Support 1.3. Resource Utilization 1.4. Release Information
1.2. Low Latency 40G Ethernet Intel® FPGA IP Device Family and Speed Grade Support x
1.2.1. Low Latency 40G Ethernet Intel® FPGA IP Device Family Support 1.2.2. Low Latency 40G Ethernet Intel® FPGA IP Device Speed Grade Support
3. Getting Started x
3.1. Introduction to Intel® FPGA IP 3.2. Installing and Licensing Intel® FPGA 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 Intel® FPGA IP Functional Description 4.2. GTS Transceiver Configuration 4.3. TX Datapath 4.4. RX Datapath 4.5. Flow Control 4.6. Link Fault Signaling Interface
4.3. TX Datapath x
4.3.1. TX MAC 4.3.2. TX PCS 4.3.3. PMA
4.3.1. TX 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. TX Avalon® Streaming Filter
4.4. RX Datapath x
4.4.1. RX MAC 4.4.2. RX PCS
4.4.1. RX 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. TX 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. TX MAC Interface to User Logic 6.2. RX MAC Interface to User Logic 6.3. TX PCS Interface to User Logic 6.4. RX 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 Intel® FPGA IP
7. Control, Status, and Statistics Register Descriptions x
7.1. PHY Registers 7.2. TX MAC Registers 7.3. RX MAC Registers 7.4. Pause/PFC Flow Control 7.5. Statistics Counters 7.6. Shadow Register
1. About the Low Latency 40G Ethernet Intel® FPGA IP
2. Low Latency 40G Ethernet Intel® FPGA 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 Intel® FPGA IPs
9. Document Revision History for the Low Latency 40G Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

4.4.1.3. IP Core Strict SFD Checking

The Low Latency 40G Ethernet Intel® FPGA IP RX MAC checks all incoming packets for a correct Start byte (0xFB). If you turn on Enable Strict SFD check in the Low Latency 40G Ethernet Intel® FPGA IP parameter editor, you enable RX MAC to check the incoming preamble and SFD for the following values:

  • SFD = 0xD5
  • Preamble = 0x555555555555

The RX MAC checks one or both of these values depending on the values in bits [4:3] of the RXMAC_CONTROL register at offset 0x50A.

The function is illustrated in the table below.

Table 11.  Strict SFD/Preamble Checking
Enable Strict SFD check 0x50A[4]: Preamble Check 0x50A[3]: SFD Check Fields Checked Behavior if Check Fails
0 Don't Care Don't Care Nothing The IP passes the SOP EOP.
1 0 0 Nothing
0 1 SFD The IP drops the packet.
1 0 Preamble
1 1 Preamble and SFD
Level Two Title