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

4.8.2. XON/XOFF Pause Frames

The sender transmits a PFC frame with the specified PFC pause quanta value when it receives an XOFF request. If an enabled priority queue is in the XOFF condition, a new PFC frame is transmitted after the minimum time gap. You specify the minimum time gap in the per priority queue TX Flow Control Signal XOFF Request Hold Quanta register. The minimum time gap between two consecutive PFC frames is 1 pause quanta or 512-bit times. PFC frame transmission ends when none of the PFC interfaces of all enabled priority queues is requesting PFC frames.

A transition from XOFF to XON in any enabled priority queue triggers the IP core to transmit a PFC frame with pause quanta of 0 for the associated priority queue. The IP core sends a single XON flow control frame. In the rare case that the XON frame is lost or corrupted, the remote partner should still be able to resume transmission. The remote partner resumes transmission after the duration specified in the previous XOFF flow control frame expires.

In the case of standard flow control, the IP core transmits Pause frames instead of PFC frames. The transmission behavior is identical.

When the IP core is in standard flow control mode and receives a Pause frame, the IP core stops processing TX client data, either immediately or at the next frame boundary. Client data transmission resumes when all of the following conditions are true:

  • The time specified by the pause quanta has elapsed and there is no new quanta value
  • A valid pause frame with 0 pause duration has been received

A Pause frame has no effect if the associated TX Flow Control Enable register bit is set to disable XON and XOFF flow control.

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