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

7.3. RX MAC Avalon ST Aligned Client Interface

The F-Tile Ethernet Intel® FPGA Hard IP RX client interface in MAC+PCS variations employs the Avalon® streaming interface protocol. The Avalon® streaming interface protocol is a synchronous point-to-point, unidirectional interface that connects the producer of a data stream (source) to a consumer of data (sink). The key properties of this interface include:

  • Start of packet (SOP) and end of packet (EOP) signals delimit frame transfers.
  • The SOP must always be in the MSB, simplifying the interpretation and processing of data you receive on this interface.
  • A valid signal qualifies signals from source to sink.

The RX MAC acts as a source and the client acts as a sink in the receive direction.

Table 36.  Signals of the RX MAC Avalon ST Client InterfaceAll interface signals are clocked by the RX clock (i_clk_rx). The signal names are standard Avalon® streaming interface signals.

Name

Width

Description

o_rx_data[511:0]

o_rx_data[127:0]

o_rx_data[63:0]

512 bits (100GE)

128 bits (50GE/40GE)

64 bits (25GE/10GE)

Output data to the MAC when the rate is 10GE/25/40GE/50GE/100GE. Bits 0 is the LSB.

o_rx_valid

1 bit

When asserted, indicates that RX data is valid. Only valid between the SOP and EOP signals.

This signal might be deasserted between the assertion of the SOP and EOP signals.

o_rx_empty[5:0]

o_rx_empty[3:0]

o_rx_empty[2:0]

6 bits (100GE)

4 bits (50GE/40GE)

3 bits (10GE/25GE)

Indicates the number of empty bytes on the RX data signal when EOP signal is asserted, starting from the least significant byte (LSB).

o_rx_startofpacket

1 bit

When asserted, indicates that the RX data signal holds the first clock cycle of data in a packet (start of packet). The IP core asserts this signal for only a single clock cycle for each packet.

When the SOP signal is asserted, the MSB of the RX data signal drives the start of packet.

o_rx_endofpacket

1 bit

When asserted, indicates that the RX data signal holds the final clock cycle of data in a packet (end of packet). The IP core asserts this signal for only a single clock cycle for each packet.

In the case of an undersized frame or in the case of a frame that is exactly 64 bytes long, the SOP and EOP signals might be asserted in the same clock cycle.

o_rx_error[5:0]

6 bits Reports certain types of errors in the Ethernet frame whose contents are currently being transmitted on the client interface. This signal is valid in EOP cycles only.

The individual bits report different types of errors:

  • Bit [0]: Malformed packet error. If this bit has the value of 1, the packet is malformed. The IP core identifies a malformed packet when it receives a control character that is not a terminate character.
  • Bit [1]: CRC error. If this bit has the value of 1, the IP core detected a CRC error, error character in the frame, malformed, undersized, or truncated packets..
  • Bit [2]: undersized or oversized frame.

    The IP core does not recognize an incoming frame of size eight bytes or less as a frame, and those cases are not reported here. If the preamble-passthrough and CRC forwarding settings cause the RX MAC to strip out bytes such that only eight bytes or less remain in the frame, the IP core also does not recognize the frame, and those cases are not reported here. If the frame is malformed, the case is not reported here.

  • Bit [3]: Reserved.
  • Bit [4]: payload length error. If this bit has the value of 1, the payload received in the frame is shorter than the length field value, and the value in the length field is less than or equal 1500 bytes. If the frame is oversized or undersized, the case is not reported here. If the frame is malformed, the case is not reported here.
  • Bit [5]: Reserved.

o_rxstatus_valid

1 bit When asserted, indicates that o_rxstatus_data is driving valid data.

o_rxstatus_data[39:0]

40 bits

Specifies information about the received frame. The following fields are defined:

  • Bits [39:38]: Reserved.
  • Bit [37]: When asserted, indicates a BCAST/MCAST frame
  • Bit [36]: Reserved
  • Bit [35]: When asserted, indicates a PAUSE frame
  • Bit [34]: When asserted, indicates a Control (Type is 0x8808) frame
  • Bit[33]: When asserted, indicates a VLAN frame and a stacked VLAN frame
  • Bits[32:0]: Reserved

o_rx_preamble[63:0]

64 bits

Reads the preamble value of an RX frame. This signal is valid when the o_rx_valid and the o_rx_startofpacket signals are asserted.

This signal is available only available when you turn on Preamble Passthrough in the parameter editor for 40GE/50GE channels.
Note: For preamble passthrough with other rates, use the first eight bytes of the o_rx_data signal.
Figure 32. Receiving Data Using the RX MAC Avalon ST Client Interface

The figure above shows how to receive data using the RX MAC Avalon ST client interface. The interface complies with the Avalon® streaming interface specification.

  • Packets always start on the MSB of o_rx_data (SOP aligned).
  • When the frame ends, o_rx_empty is set to the number of unused bytes in o_rx_data, starting from the right (byte 0).
    • In this example, o_rx_data on the last cycle of the packet has 5 empty bytes.
    • The minimum number of bytes on the last cycle is 1.
  • The framing and data ports are only valid when o_rx_data is high.
Note: The interface does not take direct backpressure.
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