F-Tile Ethernet Intel® FPGA Hard IP User Guide

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ID 683023
Date 10/04/2021
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Document Table of Contents
Document Table of Contents x
1. Overview 2. Getting Started 3. F-Tile Ethernet Intel® FPGA Hard IP Parameters 4. Functional Description 5. Clocks 6. Resets 7. Interface Overview 8. Configuration Registers 9. Supported Modules and IPs 10. Supported Tools 11. F-Tile Ethernet Intel® FPGA Hard IP User Guide Archives 12. Document Revision History
1. Overview x
1.1. Ethernet System in F-Tile Overview 1.2. F-Tile Ethernet Intel® FPGA Hard IP Overview
1.2. F-Tile Ethernet Intel® FPGA Hard IP Overview x
1.2.1. Device Family Support 1.2.2. Resource Utilization 1.2.3. Release Information
2. Getting Started x
2.1. Installing and Licensing F-Tile Ethernet Intel® FPGA Hard IP Cores 2.2. Specifying the IP Core Parameters and Options 2.3. Reference and System PLL Clock for your IP Design 2.4. Generated File Structure 2.5. Generating Tile Files 2.6. IP Core Testbenches
4. Functional Description x
4.1. Datapath Description 4.2. F-Tile Ethernet Intel® FPGA Hard IP MAC 4.3. PCS, OTN, and FlexE Modes 4.4. Precision Time Protocol 4.5. Auto-Negotiation and Link Training
4.2. F-Tile Ethernet Intel® FPGA Hard IP MAC x
4.2.1. MAC TX Datapath 4.2.2. MAC RX Datapath 4.2.3. Congestion and Flow Control Using PAUSE or Priority Flow Control (PFC) 4.2.4. Link Fault Signaling 4.2.5. Order of Ethernet Transmission
4.2.1. MAC TX Datapath x
4.2.1.1. TX Preamble, Start, and SFD Insertion 4.2.1.2. Source Address Insertion 4.2.1.3. Length/Type Field Processing 4.2.1.4. Frame Padding 4.2.1.5. Frame Check Sequence (CRC-32) Insertion 4.2.1.6. Inter-Packet Gap Generation and Insertion
4.2.2. MAC RX Datapath x
4.2.2.1. RX Preamble Processing 4.2.2.2. RX Strict SFD Checking 4.2.2.3. RX FCS Checking 4.2.2.4. RX Malformed Packet Handling 4.2.2.5. Removing PAD Bytes and FCS Bytes from RX Frames 4.2.2.6. RX Undersized Frames, Oversized Frames, and Frames with Length Errors 4.2.2.7. Inter-Packet Gap
4.2.3. Congestion and Flow Control Using PAUSE or Priority Flow Control (PFC) x
4.2.3.1. Conditions Triggering XOFF Frame Transmission 4.2.3.2. Conditions Triggering XON Frame Transmission 4.2.3.3. Pause Control and Generation Interface 4.2.3.4. Pause Control Frame Filtering
4.3. PCS, OTN, and FlexE Modes x
4.3.1. PCS Mode 4.3.2. OTN Mode 4.3.3. FlexE Mode
4.4. Precision Time Protocol x
4.4.1. Features 4.4.2. PTP Timestamp Accuracy 4.4.3. PTP Client Flow 4.4.4. RX Virtual Lane Offset Calculation for No FEC Variants 4.4.5. Virtual Lane Order and Offset Values 4.4.6. UI Adjustment 4.4.7. Reference Time Interval 4.4.8. Minimum and Maximum Reference Time (TAM) Interval for UI Measurement (Hardware) 4.4.9. UI Value and PMA Delay 4.4.10. Routing Delay Adjustment for Advanced Timestamp Accuracy Mode
4.4.3. PTP Client Flow x
4.4.3.1. PTP TX Client Flow 4.4.3.2. PTP RX Client Flow
4.4.6. UI Adjustment x
4.4.6.1. TX UI Adjustment 4.4.6.2. RX UI Adjustment
5. Clocks x
5.1. Clock Connections in Single Instance Operation 5.2. Clock Connections in Multiple Instance Operation 5.3. Clock Connections in MAC Asynchronous FIFO Operation 5.4. Clock Connections in PTP-Based Synchronous and Asynchronous Operation 5.5. Clock Connections in Synchronous Ethernet Operation 5.6. Custom Cadence
6. Resets x
6.1. Reset Signals 6.2. Reset Sequence
7. Interface Overview x
7.1. Status Interface 7.2. TX MAC Avalon ST Client Interface 7.3. RX MAC Avalon ST Aligned Client Interface 7.4. TX MAC Segmented Client Interface 7.5. RX MAC Segmented Client Interface 7.6. MAC Flow Control Interface 7.7. PCS Mode TX Interface 7.8. PCS Mode RX Interface 7.9. FlexE and OTN Mode TX Interface 7.10. FlexE and OTN Mode RX Interface 7.11. Custom Rate Interface 7.12. Reconfiguration Interfaces 7.13. Precision Time Protocol Interface
7.2. TX MAC Avalon ST Client Interface x
7.2.1. TX MAC Avalon ST Client Interface with Disabled Preamble Passthrough 7.2.2. TX MAC Avalon ST Client Interface with Enabled Preamble Passthrough 7.2.3. Using MAC Avalon ST skip_crc Signal to Control Source Address, PAD, and CRC Insertion 7.2.4. Using MAC Avalon ST i_tx_error Signal to Mark Packets Invalid
7.3. RX MAC Avalon ST Aligned Client Interface x
7.3.1. RX MAC Avalon ST Client Interface with Disabled Preamble Passthrough 7.3.2. RX MAC Avalon ST Client Interface with Enabled Passthrough and RX CRC Forwarding 7.3.3. RX MAC Adapter Limitations 7.3.4. RX MAC Avalon ST Client Interface Status
7.4. TX MAC Segmented Client Interface x
7.4.1. TX MAC Segmented Client Interface with Disabled Preamble Passthrough 7.4.2. TX MAC Segmented Client Interface with Enabled Preamble Passthrough 7.4.3. Using MAC Segmented skip_crc Signal to Control Source Address, PAD, and CRC Insertion 7.4.4. Using MAC Segmented i_tx_mac_error to Mark Packets Invalid
7.5. RX MAC Segmented Client Interface x
7.5.1. RX MAC Segmented Client Interface with Disabled Preamble Passthrough 7.5.2. RX MAC Segmented Client Interface with Enabled Passthrough and RX CRC Forwarding 7.5.3. RX MAC Segmented Client Interface Status and Errors
7.12. Reconfiguration Interfaces x
7.12.1. Ethernet Reconfiguration Interfaces 7.12.2. Transceiver Reconfiguration Interfaces
7.13. Precision Time Protocol Interface x
7.13.1. Time-of-Day Interface 7.13.2. TX 2-Step Timestamp Interface 7.13.3. TX 1-Step Timestamp Interface 7.13.4. RX Timestamp Interface 7.13.5. PTP Status Interface 7.13.6. PTP Tile Interface
7.13.3. TX 1-Step Timestamp Interface x
7.13.3.1. PTP Field Offset for 1-Step Operation
8. Configuration Registers x
8.1. Ethernet Avalon® Memory-Mapped Interface Address Space 8.2. Transceiver Avalon® Memory-Mapped Interface Address Space
8.1. Ethernet Avalon® Memory-Mapped Interface Address Space x
8.1.1. Ethernet Hard IP Core CSRs 8.1.2. FEC and Transceiver Control and Status Registers
9. Supported Modules and IPs x
9.1. F-Tile Auto-Negotiation and Link Training For Ethernet Intel® FPGA IP 9.2. PTP Tile Adapter
9.1. F-Tile Auto-Negotiation and Link Training For Ethernet Intel® FPGA IP x
9.1.1. Overview 9.1.2. Release Information 9.1.3. Functional Description 9.1.4. Parameters 9.1.5. Clocks and Resets 9.1.6. Registers
9.2. PTP Tile Adapter x
9.2.1. Overview 9.2.2. Clocks, Reset, and Interface Ports 9.2.3. PTP Asymmetry Delay Reconfiguration Interface 9.2.4. PTP Peer-to-Peer MeanPathDelay Reconfiguration Interface
10. Supported Tools x
10.1. F-Tile Channel Placement Tool 10.2. Ethernet Toolkit Overview
10.2. Ethernet Toolkit Overview x
10.2.1. Features
1. Overview
2. Getting Started
3. F-Tile Ethernet Intel® FPGA Hard IP Parameters
4. Functional Description
5. Clocks
6. Resets
7. Interface Overview
8. Configuration Registers
9. Supported Modules and IPs
10. Supported Tools
11. F-Tile Ethernet Intel® FPGA Hard IP User Guide Archives
12. Document Revision History

7.7. PCS Mode TX Interface

The F-Tile Ethernet Intel® FPGA Hard IP TX client interface in PCS variations employs the Media Independent Interface (MII) protocol.

The client acts as a source and the TX PCS acts as a sink in the transmit direction.

Table 45.  Signals of the MII TX Client InterfaceAll interface signals are clocked by the TX clock. The signal names are standard Avalon® streaming interface signals.

Signal Name

Width

Description

i_tx_mii_d[1023:0]

i_tx_mii_d[511:0]

i_tx_mii_d[255:0]

i_tx_mii_d[127:0]

i_tx_mii_d[63:0]

1024 bits (400GE)

512 bits (200GE)

256 bits (100GE)

128 bits (40GE/50GE)

64 bits(10GE/25GE)

TX MII data. Data must be in MII encoding. i_tx_mii_d[7:0] holds the first byte the IP core transmits on the Ethernet link. i_tx_mii_d[0] holds the first bit the IP core transmits on the Ethernet link.

While the TX MII valid signal has the value of 0 or the alignment marker insertion bit signal has the value of 1, and for one additional clock cycle, you must hold the value of this signal stable, a behavior called freezing the signal value.

i_tx_mii_c[127:0]

i_tx_mii_c[63:0]

i_tx_mii_c[31:0]

i_tx_mii_c[15:0]

i_tx_mii_c[7:0]

128 bits (400GE)

64 bits (200GE)

32 bits (100GE)

16 bits (40GE/50GE)

8 bits(10GE/25GE)

 TX MII control bits. Each bit corresponds to a byte of the TX MII data signal. For example, i_tx_mii_c[0] corresponds to i_tx_mii_d[7:0], i_tx_mii_c[1] corresponds to i_tx_mii_d[15:8], and so on.

If the value of a bit is 1, the corresponding data byte is a control byte. If the value of a bit is 0, the corresponding data byte is data.

i_tx_mii_valid

1 bit Indicates that the TX MII data signal is valid.

You must assert this signal a fixed number of clock cycles after the IP core raises ready signal, and must deassert this signal the same number of clock cycles after the IP core deasserts the ready signal. The number must be in the range of 1–6 clock cycles.

o_tx_mii_ready

1 bit Indicates the PCS is ready to receive new data.

i_tx_mii_am

1 bit Alignment marker insertion bit.
Figure 37. Transmitting Data Using the PCS Mode TX Interface

The figure above shows how to write packets directly to the PCS mode TX interface.

  • The packets are written using MII.
    • Each byte in i_tx_mii_d has a corresponding bit in i_tx_mii_c that indicates whether the byte is a control byte or a data byte; for example, i_tx_mii_c[1] is the control bit for i_tx_mii_d[15:8].
  • i_tx_mii_valid should conform to these conditions:
    • Assert the valid signal only when the ready signal is asserted, and deassert only when the ready signal is deasserted.
    • The two signals can be spaced by a fixed latency between 1 and 6 cycles.
    • When the valid signal deasserts, i_tx_mii_d and i_tx_mii_c must be paused.
  • The byte order for the PCS mode TX interface is opposite of the byte order for the MAC Avalon® streaming interface. Bytes flow from LSB to MSB; the first byte to be transmitted from the interface is i_tx_mii_d[7:0].
  • The bit order for the PCS mode TX interface is the same as the bit order of the MAC client. The first bit to be transmitted from the interface is i_tx_mii_d[0].
Note: The PCS mode TX interface is not SOP aligned. Any legal ordering of packets in MII format is accepted.
Table 46.  Writing a Start Packet Block with Preamble to the PCS Mode TX Interface
MII Data MII Control Ethernet Packet Byte
i_tx_mii_d[7:0] 0xFB i_tx_mii_c[0] 1 Start of Packet
i_tx_mii_d[15:8] 0x55 i_tx_mii_c[1] 0 Preamble
i_tx_mii_d[23:16] 0x55 i_tx_mii_c[2] 0 Preamble
i_tx_mii_d[31:24] 0x55 i_tx_mii_c[3] 0 Preamble
i_tx_mii_d[39:32] 0x55 i_tx_mii_c[4] 0 Preamble
i_tx_mii_d[47:40] 0x55 i_tx_mii_c[5] 0 Preamble
i_tx_mii_d[55:48] 0x55 i_tx_mii_c[6] 0 Preamble
i_tx_mii_d[63:56] 0xD5 i_tx_mii_c[7] 0 SFD
Figure 38. Inserting Alignment Markers

The fabric controls the timing of alignment marker insertion. Alignment markers cannot be delayed without disrupting the Ethernet link. Use valid cycles to count the alignment markers. When i_tx_mii_valid is low, the alignment marker counters and input must freeze.

For alignment marker counts, you only use valid cycles. When i_tx_mii_valid is low, the alignment marker counters and input data must freeze.

The number of cycles for i_tx_mii_am to remain high depends on the rate of the interface.

  • 400GE: 2 cycles
  • 200GE: 2 cycles
  • 100GE: 5 cycles
  • 50GEx2 with RS-FEC or 50GEx1: 2 cycles
  • 50GEx2 without RS-FEC or 40GE: 2 cycles
  • 25GE with RS-FEC: 4 cycles)

The number of cycles for am period depends on the rate of the interface and whether in simulation or hardware.

  • In simulation, it is common to use a reduced am period for both sides of the link to increase lock-time speed.
    • 400GE: 640
    • 200GE: 640
    • 100GE: 1280
    • 50GEx2 with RS-FEC: 512
    • 50GEx2 without RS-FEC or 50GE: 640
    • 40GE: 128
    • 25GE with RS-FEC: 1280
  • In hardware.
    • 400GE: 2560
    • 200GE: 2560
    • 100GE: 2560
    • 50GEx2 with ETC RS(272,258) or 50GEx1: 2560
    • 25GE with RS-FEC: 2560

For proper operation, program the MAC, PCS, and optional FEC to use the same am period.

In FEC modes, the TX datapath does not come completely out of reset until at least 2 alignment marker periods passed. You must start driving i_tx_mii_am at the proper interval before o_tx_pll_lanes_stable goes high. You may drive the signal as soon as o_tx_pll_locked has gone high and o_tx_mii_ready starts toggling. When the external custom rate interface is enabled, you must start driving i_custom_cadence. For more information, refer to the Custom Rate Interface.

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