Low Latency Ethernet 10G MAC Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

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ID 813663
Date 10/07/2024
Public
Document Table of Contents
Document Table of Contents x
1. Low Latency Ethernet 10G MAC Intel® FPGA IP Overview 2. Getting Started 3. Functional Description 4. Parameter Settings for the Low Latency Ethernet 10G MAC Intel® FPGA IP Core 5. Interface Signals 6. Configuration Registers 7. Low Latency Ethernet 10G MAC Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs Archives 8. Document Revision History for the Low Latency Ethernet 10G MAC Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs
1. Low Latency Ethernet 10G MAC Intel® FPGA IP Overview x
1.1. Features 1.2. Release Information 1.3. Low Latency Ethernet 10G MAC Operating Modes 1.4. Device Family Support 1.5. Performance and Resource Utilization
1.5. Performance and Resource Utilization x
1.5.1. Resource Utilization 1.5.2. TX and RX Latency
2. Getting Started x
2.1. Introduction to Intel® FPGA IP Cores 2.2. Installing and Licensing Intel® FPGA IP Cores 2.3. Specifying the IP Parameters and Options ( Quartus® Prime Pro Edition) 2.4. Generated File Structure 2.5. Simulating Intel® FPGA IP Cores 2.6. Upgrading the Low Latency Ethernet 10G MAC Intel® FPGA IP Core 2.7. Low Latency Ethernet 10G MAC Intel® FPGA IP Design Examples
2.6. Upgrading the Low Latency Ethernet 10G MAC Intel® FPGA IP Core x
2.6.1. Design Considerations
2.6.1. Design Considerations x
2.6.1.1. Timing Constraints
2.6.1.1. Timing Constraints x
2.6.1.1.1. Pseudo-Static CSR Fields 2.6.1.1.2. Clock Crosser 2.6.1.1.3. Dual Clock FIFO
2.7. Low Latency Ethernet 10G MAC Intel® FPGA IP Design Examples x
2.7.1. Low Latency Ethernet 10G MAC Intel® FPGA IP Design Example for Agilex™ 5 Devices
3. Functional Description x
3.1. Architecture 3.2. Interfaces 3.3. Frame Types 3.4. TX Datapath 3.5. RX Datapath 3.6. Flow Control 3.7. Reset Requirements 3.8. XGMII Error Handling (Link Fault) 3.9. IEEE 1588v2
3.4. TX Datapath x
3.4.1. Padding Bytes Insertion 3.4.2. Address Insertion 3.4.3. CRC-32 Insertion 3.4.4. XGMII Encapsulation 3.4.5. Inter-Packet Gap Generation and Insertion 3.4.6. XGMII Transmission 3.4.7. TX Promiscuous (Transparent) Mode 3.4.8. TX Timing Diagrams
3.5. RX Datapath x
3.5.1. XGMII Decapsulation 3.5.2. CRC Checking 3.5.3. Address Checking 3.5.4. Frame Type Checking 3.5.5. Length Checking 3.5.6. CRC and Padding Bytes Removal 3.5.7. Overflow Handling 3.5.8. RX Promiscuous (Transparent) Mode 3.5.9. RX Timing Diagrams
3.5.5. Length Checking x
3.5.5.1. Frame Length 3.5.5.2. Payload Length
3.6. Flow Control x
3.6.1. IEEE 802.3 Flow Control 3.6.2. Priority-Based Flow Control
3.6.1. IEEE 802.3 Flow Control x
3.6.1.1. Pause Frame Reception 3.6.1.2. Pause Frame Transmission
3.6.2. Priority-Based Flow Control x
3.6.2.1. PFC Frame Reception 3.6.2.2. PFC Frame Transmission
3.9. IEEE 1588v2 x
3.9.1. Architecture 3.9.2. TX Datapath 3.9.3. RX Datapath 3.9.4. Frame Format
3.9.4. Frame Format x
3.9.4.1. PTP Packet in IEEE 802.3 3.9.4.2. PTP Packet over UDP/IPv4 3.9.4.3. PTP Packet over UDP/IPv6
5. Interface Signals x
5.1. Clock and Reset Signals 5.2. Speed Selection Signal 5.3. Error Correction Signals 5.4. Avalon® Memory-Mapped Interface Programming Signals 5.5. Avalon® Streaming Data Interfaces 5.6. Avalon® Streaming Flow Control Signals 5.7. Avalon® Streaming Status Interface 5.8. PHY-side Interfaces 5.9. IEEE 1588v2 Interfaces
5.5. Avalon® Streaming Data Interfaces x
5.5.1. Avalon® Streaming TX Data Interface Signals 5.5.2. Avalon® Streaming RX Data Interface Signals 5.5.3. Avalon® Streaming Data Interface Clocks
5.7. Avalon® Streaming Status Interface x
5.7.1. Avalon® Streaming Interface TX Status Signals 5.7.2. Avalon® Streaming Interface RX Status Signals
5.8. PHY-side Interfaces x
5.8.1. XGMII TX Signals 5.8.2. XGMII RX Signals 5.8.3. GMII TX Signals 5.8.4. GMII RX Signals 5.8.5. Clock Enable Signals
5.9. IEEE 1588v2 Interfaces x
5.9.1. IEEE 1588v2 Egress TX Signals 5.9.2. IEEE 1588v2 Ingress RX Signals 5.9.3. IEEE 1588v2 Interface Clocks
6. Configuration Registers x
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. RX Configuration and Status Registers 6.8. ECC Registers 6.9. Statistics Registers 6.10. Timestamp Registers
6.10. Timestamp Registers x
6.10.1. Calculating PHY Total Latency 6.10.2. Calculating Deterministic Latency 6.10.3. PTP Register Configuration
1. Low Latency Ethernet 10G MAC Intel® FPGA IP Overview
2. Getting Started
3. Functional Description
4. Parameter Settings for the Low Latency Ethernet 10G MAC Intel® FPGA IP Core
5. Interface Signals
6. Configuration Registers
7. Low Latency Ethernet 10G MAC Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs Archives
8. Document Revision History for the Low Latency Ethernet 10G MAC Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

6.10.2. Calculating Deterministic Latency

Note: Please refer to the configuration registers of Multirate PHY IP for more information on the registers used in the Deterministic Latency calculation.
Table 43.  Deterministic Latency Parameter Description
Item Value Description
sampling_clk_period

4.375ns (1G/2.5G (MGBASE))

6.5ns (1G/2.5G/5G/10G/10M/100M (USXGMII))

Period for sampling clock of 228.571 MHz for 1G/2.5G (MGBASE) and 153.846 MHz for 1G/2.5G/5G/10G/10M/100M (USXGMII).
UI period
  • 0.8ns (1G)
  • 0.32ns (2.5G (MGBASE))
  • 0.09696ns (1G/2.5G/5G/10G/10M/100M/ (USXGMII))

Period for unit interval
bitslip_cnt Read from pcs_bitslip_cnt[6:0] Read from the Ethernet Reconfiguration Interface register (pcs_bitslip_cnt) at base 0x60000, register offset 0x110.

Applicable for 10M/100M/1G/2.5G/5G/10G (USXGMII) only.
dlpulse_alignment Read from pcs_bitslip_cnt[7] Read from the Ethernet Reconfiguration Interface register (pcs_bitslip_cnt) at base 0x60000, register offset 0x110.

Applicable for 10M/100M/1G/2.5G/5G/10G (USXGMII) only.
tx_delay (TxDL)

For 1G/2.5G (MGBASE):

Read from EFIFO-DL registers

[0x19:0x18] – [20:0]

For 10M/100M/1G/2.5G/5G/10G (USXGMII):

Read from PTP_DL_TX register

0x421[20:0]

TX delay value in sampling_clk cycles, fixed point format Q13.8.

Bit [20:8] is integer, bit [7:0] is fractional.

Example: tx_delay = 0x27F4,

Bit [20:8] = 0x27 = 39,

Bit [7:0] = 0xF4 = 244/2^8 = 0.953125,

Hence, tx_delay = 39.953125 clock cycles.

rx_delay (RxDL)

For 1G/2.5G (MGBASE):

Read from EFIFO-DL register

[0x1B:0x1A] – [20:0]

For 10M/100M/1G/2.5G/5G/10G (USXGMII):

Read from PTP_DL_RX register

0x422[20:0]

RX delay value in sampling_clk cycles, fixed point format Q13.8.

Bit [20:8] is integer, bit [7:0] is fractional.

Example: rx_delay = 0x27F4,

Bit [20:8] = 0x27 = 39,

Bit [7:0] = 0xF4 = 244/2^8 = 0.953125,

Hence, rx_delay = 39.953125 clock cycles.

TX PMA Delay
  • For 1G/2.5G (MGBASE):

    Simulation: 49

    Hardware: 49

  • For 10M/100M/1G/2.5G/5G/10G (USXGMII):

    Simulation: 79

    Hardware: 80

TX PMA delay in the number of UI. Multiply by UI period to convert to nanoseconds and fractional nanoseconds format.
RX PMA Delay
  • For 1G/2.5G (MGBASE):

    Simulation: 67.5

    Hardware: 67.5

  • For 10M/100M/1G/2.5G/5G/10G (USXGMII):

    Simulation: 88

    Hardware: 88

RX PMA delay in the number of UI. Multiply by UI period to convert to nanoseconds and fractional nanoseconds format.

To calculate the TX and RX latency:

For 1G/2.5G (MGBASE): 
TX Latency = TxDL * (sampling_clock_period in ns)
RX Latency = RxDL * (sampling_clock_period in ns)

For 10M/100M/1G/2.5G/5G/10G (USXGMII): 
TX Latency = TxDL * (sampling_clock_period in ns)
RX Latency = RxDL * (sampling_clock_period in ns) + (- bitslip_cnt - 33 * dlpulse_alignment) * (UI period in ns)
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