Low Latency 50G Ethernet Intel® FPGA IP User Guide: Stratix® 10 Devices

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ID 683675
Date 4/09/2024
Public
Document Table of Contents
Document Table of Contents x
1. About the Low Latency 50G Ethernet IP Core 2. Getting Started 3. Low Latency 50G Ethernet Intel® FPGA IP Parameters 4. Functional Description 5. Interfaces and Signal Descriptions 6. IP Core Register Descriptions 7. Document Revision History for the Low Latency 50G Ethernet Intel® FPGA IP User Guide: Stratix® 10 Devices
1. About the Low Latency 50G Ethernet IP Core x
1.1. Release Information 1.2. Supported Features 1.3. Device Family Support 1.4. Device Speed Grade Support 1.5. IP Core Verification 1.6. Performance and Resource Utilization
1.5. IP Core Verification x
1.5.1. Simulation Environment 1.5.2. Compilation Checking 1.5.3. Hardware Testing
2. Getting Started x
2.1. Installing and Licensing Intel® FPGA IP Cores 2.2. Specifying the Low Latency 50G Ethernet IP Core Parameters and Options 2.3. Simulating the IP Core 2.4. Generated File Structure 2.5. Integrating Your IP Core in Your Design 2.6. Compiling the Full Design and Programming the FPGA
2.1. Installing and Licensing Intel® FPGA IP Cores x
2.1.1. Intel® FPGA IP Evaluation Mode
2.5. Integrating Your IP Core in Your Design x
2.5.1. Pin Assignments 2.5.2. Adding the Transceiver PLL 2.5.3. Placement Settings for the Low Latency 50G Ethernet IP Core
4. Functional Description x
4.1. TX MAC Datapath 4.2. TX PCS 4.3. RX MAC Datapath 4.4. RX PCS 4.5. Link Fault Signaling Interface 4.6. User Interface to Ethernet Transmission 4.7. Auto Negotiation and Link Training 4.8. Flow Control 4.9. Reset
4.1. TX MAC Datapath x
4.1.1. Frame Padding 4.1.2. Preamble Insertion 4.1.3. Inter-Packet Gap Generation and Insertion
4.3. RX MAC Datapath x
4.3.1. IP Core Preamble Processing 4.3.2. IP Core Strict SFD Checking 4.3.3. IP Core Malformed Packet Handling 4.3.4. Length/Type Field Processing 4.3.5. RX CRC Checking and Dynamic Forwarding
4.3.4. Length/Type Field Processing x
4.3.4.1. Length Checking
4.6. User Interface to Ethernet Transmission x
4.6.1. Order of Transmission 4.6.2. Bit Order For TX and RX Datapaths
4.8. Flow Control x
4.8.1. TX Pause/PFC Flow Control Transmission 4.8.2. XON/XOFF Pause Frames
5. Interfaces and Signal Descriptions x
5.1. TX MAC Interface to User Logic 5.2. RX MAC Interface to User Logic 5.3. Transceivers 5.4. Transceiver Reconfiguration Signals 5.5. Avalon® Memory-Mapped Management Interface 5.6. Miscellaneous Status and Debug Signals 5.7. Reset Signals 5.8. Flow Control Interface
5.4. Transceiver Reconfiguration Signals x
5.4.1. Disabling Background Calibration
6. IP Core Register Descriptions x
6.1. PHY Registers 6.2. TX MAC Registers 6.3. RX MAC Registers 6.4. Flow Control Registers 6.5. Statistics Registers 6.6. Auto-Negotiation and Link Training Registers
6.5. Statistics Registers x
6.5.1. TX Statistics Registers 6.5.2. RX Statistics Registers
6.6. Auto-Negotiation and Link Training Registers x
6.6.1. AN/LT Sequencer Config 6.6.2. AN/LT Sequencer Status 6.6.3. Auto Negotiation Config Register 1 6.6.4. Auto Negotiation Config Register 2 6.6.5. Auto Negotiation Status Register 6.6.6. Auto Negotiation Config Register 3 6.6.7. Auto Negotiation Config Register 4 6.6.8. Auto Negotiation Config Register 5 6.6.9. Auto Negotiation Config Register 6 6.6.10. Auto Negotiation Status Register 1 6.6.11. Auto Negotiation Status Register 2 6.6.12. Auto Negotiation Status Register 3 6.6.13. Auto Negotiation Status Register 4 6.6.14. Auto Negotiation Status Register 5 6.6.15. Link Training Config Register 1 6.6.16. Link Training Config Register 2 6.6.17. Link Training Status Register 1 6.6.18. Link Training Config Register for Lane 0 6.6.19. Link Training Frame Contents for Lane 0 6.6.20. Local Transceiver TX EQ 1 Settings for Lane 0 6.6.21. Local Transceiver TX EQ 2 Settings for Lane 0 6.6.22. Local Link Training Parameters 6.6.23. Link Training Config Register for Lane 1 6.6.24. Link Training Frame Contents for Lane 1 6.6.25. Local Transceiver TX EQ 1 Settings for Lane 1 6.6.26. Local Transceiver TX EQ 2 Settings for Lane 1 6.6.27. Link Training Config Register for Lane 2 6.6.28. Link Training Frame Contents for Lane 2 6.6.29. Local Transceiver TX EQ 1 Settings for Lane 2 6.6.30. Local Transceiver TX EQ 2 Settings for Lane 2 6.6.31. Link Training Config Register for Lane 3 6.6.32. Link Training Frame Contents for Lane 3 6.6.33. Local Transceiver TX EQ 1 Settings for Lane 3 6.6.34. Local Transceiver TX EQ 2 Settings for Lane 3
1. About the Low Latency 50G Ethernet IP Core
2. Getting Started
3. Low Latency 50G Ethernet Intel® FPGA IP Parameters
4. Functional Description
5. Interfaces and Signal Descriptions
6. IP Core Register Descriptions
7. Document Revision History for the Low Latency 50G Ethernet Intel® FPGA IP User Guide: Stratix® 10 Devices

4.3.4.1. Length Checking

The MAC function checks the frame and payload lengths of basic, VLAN tagged, and stacked VLAN tagged frames.

The IP core checks that the frame length is valid—is neither undersized nor oversized. A valid frame length is at least 64 (0x40) bytes and does not exceed the following maximum value for the different frame types:

  • Basic frames—The number of bytes specified in the MAX_RX_SIZE_CONFIG register.
  • VLAN tagged frames—The value specified in the MAX_RX_SIZE_CONFIG register plus four bytes.
  • Stacked VLAN tagged frames—The value specified in the MAX_RX_SIZE_CONFIG register plus eight bytes.

If the length/type field in a basic MAC frame or the client length/type field in a VLAN tagged frame has a value less than 0x600, the IP core also checks the payload length. The IP core keeps track of the payload length as it receives a frame, and checks the length against the relevant frame field. The payload length is valid if it satisfies the following conditions:

  • The actual payload length matches the value in the length/type or client length/type field.
  • Normal frames:
    • Basic frames—the payload length is between 46 (0x2E)and 1536 (0x0600) bytes, excluding 1536.
    • VLAN tagged frames—the payload length is between 42 (0x2A)and 1536 (0x0600), excluding 1536.
    • Stacked VLAN tagged frames—the payload length is between 38 (0x26) and 1536 (0x0600), excluding 1536.
  • Jumbo frames:
    • Jumbo basic frames—the payload length is between 46 (0x2E) and the value specified in the MAX_RX_SIZE_CONFIG register minus 18 bytes.
    • Jumbo VLAN tagged frames—the payload length is between 42 (0x2A) and the value specified in the MAX_RX_SIZE_CONFIG register minus 22 bytes.
    • Jumbo stacked VLAN tagged frames—the payload length is between 38 (0x26) and the value specified in the MAX_RX_SIZE_CONFIG register minus 26 bytes.

The RX MAC does not drop frames with invalid length or invalid payload length. If the frame or payload length is not valid, the MAC function asserts output error bits.

  • l2_rx_error[2]—Undersized frame.
  • l2_rx_error[3]—Oversized frame.
  • l2_rx_error[4]—Payload length error.

If the length field value is greater than the actual payload length, the IP core asserts l2_rx_error[4]. If the length field value is less than the actual payload length, the MAC RX considers the frame to have excessive padding and does not assert l2_rx_error[4].

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