Triple-Speed Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

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ID 813669
Date 4/01/2024
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Document Table of Contents
Document Table of Contents x
1. About Triple-Speed Ethernet Intel® FPGA IP for Agilex™ 5 devices 2. Getting Started 3. Parameter Settings 4. Functional Description 5. Configuration Register Space 6. Interface Signals 7. Design Considerations 8. Timing Constraints 9. Testbench 10. Document Revision History for the Triple-Speed Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs A. Ethernet Frame Format B. Simulation Parameters
1. About Triple-Speed Ethernet Intel® FPGA IP for Agilex™ 5 devices x
1.1. Release Information 1.2. Device Family Support 1.3. Features 1.4. 10/100/1000 Ethernet MAC Versus Small MAC 1.5. High-Level Block Diagrams 1.6. Performance and Resource Utilization
2. Getting Started x
2.1. Introduction to Intel® FPGA IP Cores 2.2. Installing and Licensing Intel® FPGA IPs 2.3. Specifying the IP Core Parameters and Options 2.4. IP Core Generation Output 2.5. Simulating Intel® FPGA IP Cores
2.2. Installing and Licensing Intel® FPGA IPs x
2.2.1. Intel® FPGA IP Evaluation Mode
2.4. IP Core Generation Output x
2.4.1. Design Constraint File
3. Parameter Settings x
3.1. Core Configuration 3.2. Ethernet MAC Options 3.3. FIFO Options 3.4. PCS/Transceiver Options
4. Functional Description x
4.1. 10/100/1000 Ethernet MAC 4.2. 1000BASE-X/SGMII PCS With Optional Embedded PMA (GTS)
4.1. 10/100/1000 Ethernet MAC x
4.1.1. MAC Architecture 4.1.2. MAC Interfaces 4.1.3. MAC Transmit Datapath 4.1.4. MAC Receive Datapath 4.1.5. MAC Transmit and Receive Latencies 4.1.6. FIFO Buffer Thresholds 4.1.7. Congestion and Flow Control 4.1.8. Magic Packets 4.1.9. MAC Local Loopback 4.1.10. MAC Reset 4.1.11. PHY Management (MDIO) 4.1.12. Connecting MAC to External PHYs
4.1.3. MAC Transmit Datapath x
4.1.3.1. IP Payload Re-alignment 4.1.3.2. Address Insertion 4.1.3.3. Frame Payload Padding 4.1.3.4. CRC-32 Generation 4.1.3.5. Interpacket Gap Insertion 4.1.3.6. Collision Detection in Half-Duplex Mode
4.1.4. MAC Receive Datapath x
4.1.4.1. Preamble Processing 4.1.4.2. Collision Detection in Half-Duplex Mode 4.1.4.3. Address Checking 4.1.4.4. Frame Type Validation 4.1.4.5. Payload Pad Removal 4.1.4.6. CRC Checking 4.1.4.7. Length Checking 4.1.4.8. Frame Writing 4.1.4.9. IP Payload Alignment
4.1.4.3. Address Checking x
4.1.4.3.1. Unicast Address Checking 4.1.4.3.2. Multicast Address Resolution
4.1.6. FIFO Buffer Thresholds x
4.1.6.1. Receive Thresholds 4.1.6.2. Transmit Thresholds 4.1.6.3. Transmit FIFO Buffer Underflow
4.1.7. Congestion and Flow Control x
4.1.7.1. Remote Device Congestion 4.1.7.2. Receive FIFO Buffer and Local Device Congestion
4.1.8. Magic Packets x
4.1.8.1. Sleep Mode 4.1.8.2. Magic Packet Detection
4.1.11. PHY Management (MDIO) x
4.1.11.1. MDIO Connection 4.1.11.2. MDIO Frame Format
4.1.12. Connecting MAC to External PHYs x
4.1.12.1. Gigabit Ethernet 4.1.12.2. Programmable 10/100 Ethernet 4.1.12.3. Programmable 10/100/1000 Ethernet Operation
4.2. 1000BASE-X/SGMII PCS With Optional Embedded PMA (GTS) x
4.2.1. 1000BASE-X/SGMII PCS Architecture 4.2.2. Transmit Operation 4.2.3. Receive Operation 4.2.4. Transmit and Receive Latencies 4.2.5. GMII Converter 4.2.6. SGMII Converter 4.2.7. Auto-Negotiation 4.2.8. Ten-bit Interface 4.2.9. 1000BASE-X/SGMII PCS Reset
4.2.2. Transmit Operation x
4.2.2.1. Frame Encapsulation 4.2.2.2. 8b/10b Encoding
4.2.3. Receive Operation x
4.2.3.1. Comma Detection 4.2.3.2. 8b/10b Decoding 4.2.3.3. Frame De-encapsulation 4.2.3.4. Synchronization 4.2.3.5. Carrier Sense 4.2.3.6. Collision Detection
4.2.6. SGMII Converter x
4.2.6.1. Transmit 4.2.6.2. Receive
4.2.7. Auto-Negotiation x
4.2.7.1. 1000BASE-X Auto-Negotiation 4.2.7.2. SGMII Auto-Negotiation
5. Configuration Register Space x
5.1. MAC Configuration Register Space 5.2. PCS Configuration Register Space 5.3. Register Initialization
5.1. MAC Configuration Register Space x
5.1.1. Base Configuration Registers (Dword Offset 0x00 – 0x17) 5.1.2. Statistics Counters (Dword Offset 0x18 – 0x38) 5.1.3. Transmit and Receive Command Registers (Dword Offset 0x3A – 0x3B) 5.1.4. Supplementary Address (Dword Offset 0xC0 – 0xC7)
5.1.1. Base Configuration Registers (Dword Offset 0x00 – 0x17) x
5.1.1.1. Command_Config Register (Dword Offset 0x02)
5.2. PCS Configuration Register Space x
5.2.1. Control Register (Word Offset 0x00) 5.2.2. Status Register (Word Offset 0x01) 5.2.3. Dev_Ability and Partner_Ability Registers (Word Offset 0x04 – 0x05) 5.2.4. An_Expansion Register (Word Offset 0x06) 5.2.5. If_Mode Register (Word Offset 0x14)
5.2.3. Dev_Ability and Partner_Ability Registers (Word Offset 0x04 – 0x05) x
5.2.3.1. 1000BASE-X 5.2.3.2. SGMII MAC Mode Auto Negotiation 5.2.3.3. SGMII PHY Mode Auto Negotiation
5.3. Register Initialization x
5.3.1. Triple-Speed Ethernet System with MII/GMII or RGMII 5.3.2. Triple-Speed Ethernet System with SGMII 5.3.3. Triple-Speed Ethernet System with 1000BASE-X Interface
6. Interface Signals x
6.1. Interface Signals 6.2. Timing
6.1. Interface Signals x
6.1.1. 10/100/1000 Ethernet MAC Signals 6.1.2. 10/100/1000 Multiport Ethernet MAC Signals 6.1.3. 10/100/1000 Ethernet MAC with 1000BASE-X/SGMII PCS Signals 6.1.4. 10/100/1000 Ethernet MAC with Internal FIFO Buffers, and 1000BASE-X/SGMII 2XTBI PCS with Embedded PMA (GTS) Signals 6.1.5. 10/100/1000 Multiport Ethernet MAC with 1000BASE-X/SGMII PCS Signals 6.1.6. 1000BASE-X/SGMII PCS Signals 6.1.7. 1000BASE-X/SGMII 2XTBI PCS Signals
6.1.1. 10/100/1000 Ethernet MAC Signals x
6.1.1.1. Clock and Reset Signals 6.1.1.2. Clock Enabler Signals 6.1.1.3. MAC Control Interface Signals 6.1.1.4. MAC Status Signals 6.1.1.5. MAC Receive Interface Signals 6.1.1.6. MAC Transmit Interface Signals 6.1.1.7. Pause and Magic Packet Signals 6.1.1.8. MII/GMII/RGMII Signals 6.1.1.9. PHY Management Signals
6.1.2. 10/100/1000 Multiport Ethernet MAC Signals x
6.1.2.1. Multiport MAC Clock and Reset Signals 6.1.2.2. Multiport MAC Receive Interface Signals 6.1.2.3. Multiport MAC Transmit Interface Signals 6.1.2.4. Multiport MAC Packet Classification Signals 6.1.2.5. Multiport MAC FIFO Status Signals
6.1.3. 10/100/1000 Ethernet MAC with 1000BASE-X/SGMII PCS Signals x
6.1.3.1. TBI Interface Signals 6.1.3.2. Status LED Control Signals 6.1.3.3. SERDES Control Signals
6.1.4. 10/100/1000 Ethernet MAC with Internal FIFO Buffers, and 1000BASE-X/SGMII 2XTBI PCS with Embedded PMA (GTS) Signals x
6.1.4.1. GMII Clock Signals 6.1.4.2. GTS Transceiver Direct PHY Signals 6.1.4.3. GTS Reset Sequencer Signals
6.1.6. 1000BASE-X/SGMII PCS Signals x
6.1.6.1. PCS Control Interface Signals 6.1.6.2. PCS Reset Signals 6.1.6.3. MII/GMII Clocks and Clock Enablers 6.1.6.4. GMII 6.1.6.5. MII 6.1.6.6. SGMII Status Signals
6.1.7. 1000BASE-X/SGMII 2XTBI PCS Signals x
6.1.7.1. Clock Enablers 6.1.7.2. PCS Reset Signals 6.1.7.3. TBI Interface Signals
6.2. Timing x
6.2.1. Avalon Streaming Receive Interface 6.2.2. Avalon Streaming Transmit Interface 6.2.3. GMII Transmit 6.2.4. GMII Receive 6.2.5. RGMII Transmit 6.2.6. RGMII Receive 6.2.7. MII Transmit 6.2.8. MII Receive
7. Design Considerations x
7.1. Exposed Ports in the New User Interface 7.2. Clocking Scheme of MAC with 2XTBI PCS and Embedded PMA (GTS)
8. Timing Constraints x
8.1. Creating Clock Constraints 8.2. Recommended Clock Frequency
9. Testbench x
9.1. Triple-Speed Ethernet Testbench Architecture 9.2. Testbench Components 9.3. Testbench Verification 9.4. Testbench Configuration 9.5. Test Flow 9.6. Simulation Model
9.6. Simulation Model x
9.6.1. Generate the Simulation Model 9.6.2. Simulate the IP 9.6.3. Simulation Model Files
A. Ethernet Frame Format x
A.1. Basic Frame Format A.2. VLAN and Stacked VLAN Frame Format A.3. Pause Frame Format
A.3. Pause Frame Format x
A.3.1. Pause Frame Generation
B. Simulation Parameters x
B.1. Functionality Configuration Parameters B.2. Test Configuration Parameters
1. About Triple-Speed Ethernet Intel® FPGA IP for Agilex™ 5 devices
2. Getting Started
3. Parameter Settings
4. Functional Description
5. Configuration Register Space
6. Interface Signals
7. Design Considerations
8. Timing Constraints
9. Testbench
10. Document Revision History for the Triple-Speed Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs
A. Ethernet Frame Format
B. Simulation Parameters

4.1.3.6. Collision Detection in Half-Duplex Mode

Collision occurs only in a half-duplex network. It occurs when two or more nodes transmit concurrently. The PHY device asserts the m_rx_col signal to indicate collision.

When the MAC function detects collision during transmission, it stops the transmission and sends a 32-bit jam pattern instead. A jam pattern is a fixed pattern, 0x648532A6, and is not compared to the CRC of the frame. The probability of a jam pattern being identical to the CRC is very low, 0.532%.

If the MAC function detects a collision while transmitting the preamble or start frame delimiter (SFD) field, it sends the jam pattern only after transmitting the SFD field, which subsequently results in a minimum of a 96-bit fragment.

If the MAC function detects a collision while transmitting the first 64 bytes, including the preamble and SFD fields, the MAC function waits for an interval equal to the backoff period and then retransmits the frame. The frame is stored in a 64-byte retransmit buffer. The backoff period is generated from a pseudo-random process, truncated binary exponential backoff.

Figure 13. Frame Retransmission


The backoff time is a multiple of slot times. One slot is equal to a 512 bit times period. The number of the delay slot times, before the Nth retransmission attempt, is chosen as a uniformly distributed random integer (r) in the following range:

0 ≤ r < 2k

k = min( n , N ), where n is the number of retransmissions and N = 10.

For example, after the first collision, the backoff period, in slot time, is 0 or 1. If a collision occurs during the first retransmission, the backoff period, in slot time, is 0, 1, 2, or 3.

The maximum backoff time, in 512 bit times slots, is limited by N set to 10 as specified in the IEEE Standard 802.3.

If a collision occurs after 16 consecutive retransmissions, the MAC function reports an excessive collision condition by setting the EXCESS_COL bit in the command_config register to 1, and discards the current frame from the transmit FIFO buffer.

In networks that violate standard requirements, collision may occur after the transmission of the first 64 bytes. If this happens, the MAC function stops transmitting the current frame, discards the rest of the frame from the transmit FIFO buffer, and resumes transmitting the next available frame. You can check the LATE_COL register (command_config [12]) to verify if the MAC has discarded any frame due to a collision.

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