F-Tile Architecture and PMA and FEC Direct PHY IP User Guide

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Date 7/08/2024
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Document Table of Contents
Document Table of Contents x
1. F-Tile Overview 2. F-Tile Architecture 3. Implementing the F-Tile PMA/FEC Direct PHY Intel® FPGA IP 4. Implementing the F-Tile Reference and System PLL Clocks Intel® FPGA IP 5. F-Tile PMA/FEC Direct PHY Design Implementation 6. Supported Tools 7. Debugging F-Tile Transceiver Links 8. F-Tile Architecture and PMA and FEC Direct PHY IP User Guide Archives 9. Document Revision History for the F-Tile Architecture and PMA and FEC Direct PHY IP User Guide A. Appendix
1. F-Tile Overview x
1.1. Device Family Support
2. F-Tile Architecture x
2.1. F-Tile Building Blocks 2.2. F-Tile Placement Rules 2.3. PMA Architecture 2.4. Clock Architecture
2.1. F-Tile Building Blocks x
2.1.1. FHT and FGT PMAs 2.1.2. 400G Hard IP and 200G Hard IP 2.1.3. PMA Data Rates 2.1.4. FEC Architecture 2.1.5. PCIe* Hard IP 2.1.6. Bonding Architecture 2.1.7. Deskew Logic 2.1.8. Embedded Multi-die Interconnect Bridge (EMIB) 2.1.9. IEEE 1588 Precision Time Protocol for Ethernet 2.1.10. Clock Networks 2.1.11. Reconfiguration Interfaces
2.2. F-Tile Placement Rules x
2.2.1. PMA-to-Fracture Mapping 2.2.2. Determining Which PMA to Map to Which Fracture 2.2.3. Hard IP Placement Rules 2.2.4. IEEE 1588 Precision Time Protocol Placement Rules 2.2.5. Topologies 2.2.6. FEC Placement Rules 2.2.7. Clock Rules and Restrictions 2.2.8. Bonding Placement Rules 2.2.9. Preserving Unused PMA Lanes
2.2.1. PMA-to-Fracture Mapping x
2.2.1.1. FHT-PMA-to-400G-Hard-IP-Fracture Mapping 2.2.1.2. FGT-PMA-to-400G-Hard-IP-Fracture Mapping 2.2.1.3. FGT-PMA-to-200G-Hard-IP-Fracture Mapping
2.2.2. Determining Which PMA to Map to Which Fracture x
2.2.2.1. Implementing One 200GbE-4 Interface with 400G Hard IP and FHT 2.2.2.2. Implementing One 200GbE-2 Interface with 400G Hard IP and FHT 2.2.2.3. Implementing One 100GbE-1 Interface with 400G Hard IP and FHT 2.2.2.4. Implementing One 100GbE-4 Interface with 400G Hard IP and FGT 2.2.2.5. Implementing One 10GbE-1 Interface with 200G Hard IP and FGT 2.2.2.6. Implementing Three 25GbE-1 Interfaces with 400G Hard IP and FHT 2.2.2.7. Implementing One 50GbE-1 and Two 25GbE-1 Interfaces with 400G Hard IP and FHT 2.2.2.8. Implementing One 100GbE-1 and Two 25GbE-1 Interfaces with 400G Hard IP and FHT 2.2.2.9. Implementing Two 100GbE-1 and One 25GbE-1 Interfaces with 400G Hard IP and FHT 2.2.2.10. Implementing 100GbE-1, 100GbE-2, and 50GbE-1 Interfaces with 400G Hard IP and FHT
2.2.5. Topologies x
2.2.5.1. Topology 5: 400G Hard IP (FHT) + 200G Hard IP (FGT) Example 2.2.5.2. Topology 6a: 400G Hard IP with Mixed Transceiver Mode Example 2.2.5.3. Topology 14: 1x PCIe x4 + 400G Hard IP (FGT) with PTP Example
2.2.8. Bonding Placement Rules x
2.2.8.1. Bonded Lanes Use Case 1 2.2.8.2. Bonded Lanes Use Case 2
2.3. PMA Architecture x
2.3.1. FHT PMA Architecture 2.3.2. FGT PMA Architecture
2.3.1. FHT PMA Architecture x
2.3.1.1. FHT Transmitter PMA Architecture 2.3.1.2. FHT Receiver PMA Architecture 2.3.1.3. FHT PMA Loopback Modes
2.3.1.1. FHT Transmitter PMA Architecture x
2.3.1.1.1. FHT Transmitter Buffer and Phase Generator 2.3.1.1.2. FHT Serializer 2.3.1.1.3. FHT Gray-Coder and Pre-Coder 2.3.1.1.4. FHT Data Pattern Generator and Verifier
2.3.1.2. FHT Receiver PMA Architecture x
2.3.1.2.1. FHT Receiver Buffer and Equalizer 2.3.1.2.2. CDR Block 2.3.1.2.3. FHT Deserializer
2.3.2. FGT PMA Architecture x
2.3.2.1. FGT Transmitter PMA Architecture 2.3.2.2. FGT Receiver PMA Architecture 2.3.2.3. FGT PMA Tuning 2.3.2.4. FGT PMA Loopback Modes
2.3.2.1. FGT Transmitter PMA Architecture x
2.3.2.1.1. FGT Transmitter Buffer and Phase Generator 2.3.2.1.2. FGT Serializer 2.3.2.1.3. FGT Gray-Coder and Pre-Coder 2.3.2.1.4. FGT Data Pattern Generator and Verifier
2.3.2.2. FGT Receiver PMA Architecture x
2.3.2.2.1. FGT Receiver Buffer and Equalizer 2.3.2.2.2. Control Unit 2.3.2.2.3. FGT Deserializer
2.4. Clock Architecture x
2.4.1. Reference Clock Network 2.4.2. Datapath Clock Network 2.4.3. System PLL 2.4.4. Datapath Clock Cadences
2.4.1. Reference Clock Network x
2.4.1.1. FHT Reference Clock Network 2.4.1.2. FGT and System PLL Reference Clock Network 2.4.1.3. FGT Primary PLL Configuration
2.4.1.2. FGT and System PLL Reference Clock Network x
2.4.1.2.1. FGT Reference Clock Receiver Analog Front End
3. Implementing the F-Tile PMA/FEC Direct PHY Intel® FPGA IP x
3.1. F-Tile PMA/FEC Direct PHY Intel® FPGA IP Overview 3.2. Designing with F-Tile PMA/FEC Direct PHY Intel® FPGA IP 3.3. Configuring the IP 3.4. Signal and Port Reference 3.5. Bit Mapping for PMA and FEC Mode PHY TX and RX Datapath 3.6. Clocking 3.7. Custom Cadence Generation Ports and Logic 3.8. Asserting Reset 3.9. Bonding Implementation 3.10. Independent Port Configurations 3.11. Configuration Registers 3.12. Configurable Quartus® Prime Software Settings 3.13. Configuring the F-Tile PMA/FEC Direct PHY Intel® FPGA IP for Hardware Testing 3.14. Hardware Configuration Using the Avalon® Memory-Mapped Interface
3.1. F-Tile PMA/FEC Direct PHY Intel® FPGA IP Overview x
3.1.1. PMA Direct Supported Modes 3.1.2. FEC Direct Supported Modes 3.1.3. Unsupported PMA/FEC Modes
3.2. Designing with F-Tile PMA/FEC Direct PHY Intel® FPGA IP x
3.2.1. Preset IP Parameter Settings
3.3. Configuring the IP x
3.3.1. General and Common Datapath Options 3.3.2. TX Datapath Options 3.3.3. RX Datapath Options 3.3.4. RS-FEC (Reed Solomon Forward Error Correction) Options 3.3.5. Avalon® Memory Mapped Interface Options 3.3.6. Register Map IP-XACT Support 3.3.7. Example Design Generation 3.3.8. Analog Parameter Options
3.3.1. General and Common Datapath Options x
3.3.1.1. FGT PMA Configuration Rules for SATA mode 3.3.1.2. FGT PMA Configuration Rules for GPON Mode
3.3.2. TX Datapath Options x
3.3.2.1. TX PMA interface Parameters
3.3.3. RX Datapath Options x
3.3.3.1. RX FGT PMA Interface Options
3.4. Signal and Port Reference x
3.4.1. TX and RX Parallel and Serial Interface Signals 3.4.2. TX and RX Reference Clock and Clock Output Interface Signals 3.4.3. Reset Signals 3.4.4. RS-FEC Signals 3.4.5. Custom Cadence Control and Status Signals 3.4.6. TX PMA Control Signals 3.4.7. RX PMA Status Signals 3.4.8. TX and RX PMA and Core Interface FIFO Signals 3.4.9. PMA Avalon® Memory Mapped Interface Signals 3.4.10. Datapath Avalon® Memory Mapped Interface Signals
3.4.10. Datapath Avalon® Memory Mapped Interface Signals x
3.4.10.1. Number of Datapath Memory Mapped Avalon® Interfaces and Additional Address Bits per Interface
3.5. Bit Mapping for PMA and FEC Mode PHY TX and RX Datapath x
Total tx_parallel_data or rx_parallel_data Bit Width Equation: Example 1: Total tx/rx_parallel_data Bit Width with 2 PMA Lanes (N=2) and 8-bit PMA Width (X=1) Example 2: Total tx/rx_parallel_data Bit Width with 4 PMA Lanes (N=4) and 64-bit PMA Width (X=2) Parallel Data Mapping information for TX and RX 3.5.1. Parallel Data Mapping Information 3.5.2. TX and RX Parallel Data Mapping Information for Different Configurations 3.5.3. Example of TX Parallel Data for PMA Width = 8, 10, 16, 20, 32 (X=1) 3.5.4. Example of TX Parallel Data for PMA width = 64 (X=2) 3.5.5. Example of TX Parallel Data for PMA width = 64 (X=2) for FEC Direct Mode
3.5.2. TX and RX Parallel Data Mapping Information for Different Configurations x
3.5.2.1. TX Parallel Data Mapping Information for SATA Protocol Mode for Different Configurations
3.6. Clocking x
3.6.1. Clock Ports 3.6.2. Recommended tx/rx_coreclkin Connection and tx/rx_clkout2 Source 3.6.3. Port Widths and Recommended Connections for tx/rx_coreclkin, tx/rx_clkout, and tx/rx_clkout2 3.6.4. FGT PMA Fractional Mode 3.6.5. FGT RX CDR Clock Output
3.6.5. FGT RX CDR Clock Output x
3.6.5.1. Dynamically Configure the FGT RX CDR Clock Output
3.7. Custom Cadence Generation Ports and Logic x
3.7.1. Enabling the tx_cadence_slow_clk_locked Port 3.7.2. Rate Match FIFO
3.8. Asserting Reset x
3.8.1. Reset Signal Requirements 3.8.2. Power On Reset Requirements 3.8.3. Reset Signals—Block Level 3.8.4. Reset Signals—Descriptions 3.8.5. Status Signals—Descriptions 3.8.6. Run-time Reset Sequence—TX 3.8.7. Run-time Reset Sequence—RX 3.8.8. Run-time Reset Sequence—TX + RX 3.8.9. Run-time Reset Sequence—TX with FEC
3.8.8. Run-time Reset Sequence—TX + RX x
3.8.8.1. Run-time Reset Sequence Approximate Time Durations
3.11. Configuration Registers x
3.11.1. PMA and FEC Direct PHY Soft CSR Register Map 3.11.2. FHT PMA Register Map 3.11.3. FGT PMA Register Map 3.11.4. FEC Register Map 3.11.5. Lane Offset Address 3.11.6. Accessing Configuration Registers
3.11.6. Accessing Configuration Registers x
3.11.6.1. Accessing PMA and FEC Direct PHY Soft CSR Registers 3.11.6.2. Accessing FHT PMA Registers 3.11.6.3. Accessing FGT PMA Registers
3.11.6.2. Accessing FHT PMA Registers x
3.11.6.2.1. FHT PMA Register Address Range 0x40000 to 0x48000 3.11.6.2.2. FHT PMA Register Address Range 0x60000 to 0xF0030 3.11.6.2.3. FHT PMA Register Address 0xFFFFC
3.11.6.3. Accessing FGT PMA Registers x
3.11.6.3.1. FGT PMA Register Address Range 0x40000 to 0x48000 3.11.6.3.2. FGT PMA Register Address Range 0x62000 to 0x62004 3.11.6.3.3. FGT PMA Register Address Range 0x9003C to 0xF0028 3.11.6.3.4. FGT PMA Register Address 0xFFFFC
3.12. Configurable Quartus® Prime Software Settings x
3.12.1. FHT PMA Settings 3.12.2. FGT PMA Settings
3.13. Configuring the F-Tile PMA/FEC Direct PHY Intel® FPGA IP for Hardware Testing x
3.13.1. Using Debug Endpoint Interface within the F-Tile PMA/FEC Direct PHY Intel® FPGA IP 3.13.2. Using JTAG to Avalon® Master Bridge Intel FPGA IP
3.13.1. Using Debug Endpoint Interface within the F-Tile PMA/FEC Direct PHY Intel® FPGA IP x
3.13.1.1. RTL Connection Example for Debug Endpoint Avalon® Interface
3.13.2. Using JTAG to Avalon® Master Bridge Intel FPGA IP x
3.13.2.1. RTL Connection Example for JTAG to Avalon® Master Bridge Intel IP
3.14. Hardware Configuration Using the Avalon® Memory-Mapped Interface x
3.14.1. FHT PMA 3.14.2. FGT PMA
3.14.1. FHT PMA x
3.14.1.1. Enabling Loopback 3.14.1.2. Enabling the PRBS Generator and Verifier 3.14.1.3. TX Equalizer Settings 3.14.1.4. TX Error Injection 3.14.1.5. RX Reconvergence 3.14.1.6. Preserving Unused Lanes
3.14.2. FGT PMA x
3.14.2.1. Direct Register Method 3.14.2.2. FGT Attribute Access Method
3.14.2.1. Direct Register Method x
3.14.2.1.1. Direct Register Method Examples
3.14.2.2. FGT Attribute Access Method x
3.14.2.2.1. FGT Attribute Access Method Example 1 3.14.2.2.2. FGT Attribute Access Method Example 2 3.14.2.2.3. FGT Attribute Access Method Example 3
4. Implementing the F-Tile Reference and System PLL Clocks Intel® FPGA IP x
4.1. IP Parameters 4.2. IP Port List 4.3. Mode of System PLL - System PLL Reference Clock and Output Frequencies 4.4. Guidelines for F-Tile Reference and System PLL Clocks Intel® FPGA IP Usage 4.5. Guidelines for Refclk #i is Active At and After Device Configuration
4.5. Guidelines for Refclk #i is Active At and After Device Configuration x
4.5.1. Guidelines for System PLL Reference Clock 4.5.2. Guidelines for FGT Reference Clock
5. F-Tile PMA/FEC Direct PHY Design Implementation x
5.1. Implementing the F-Tile PMA/FEC Direct PHY Design 5.2. Instantiating the F-Tile PMA/FEC Direct PHY Intel® FPGA IP 5.3. Implementing a RS-FEC Direct Design in the F-Tile PMA/FEC Direct PHY Intel® FPGA IP 5.4. Instantiating the F-Tile Reference and System PLL Clocks Intel® FPGA IP 5.5. Enabling Custom Cadence Generation Ports and Logic 5.6. Connecting the F-Tile PMA/FEC Direct PHY Design IP 5.7. Simulating the F-Tile PMA/FEC Direct PHY Design 5.8. F-Tile Interface Planning
5.2. Instantiating the F-Tile PMA/FEC Direct PHY Intel® FPGA IP x
5.2.1. Setting General and Common Datapath Options 5.2.2. Setting TX Datapath Options 5.2.3. Setting RX Datapath Options
5.7. Simulating the F-Tile PMA/FEC Direct PHY Design x
5.7.1. PAM4 Encoding Schemes in Simulation
5.8. F-Tile Interface Planning x
5.8.1. F-Tile Interface Planner Usage Example
6. Supported Tools x
6.1. F-Tile Channel Placement Tool 6.2. F-Tile PMA and FEC Direct Port Mapping Calculator 6.3. F-Tile Clocking and Datapath Tool 6.4. F-Tile TX Equalizer Tool
7. Debugging F-Tile Transceiver Links x
7.1. F-Tile Transceiver Toolkit GUI 7.2. F-Tile Transceiver Debugging Flow Walkthrough 7.3. Transceiver Toolkit Parameter Settings 7.4. Using F-Tile Multirate IPs with Transceiver Toolkit 7.5. Troubleshooting Common Errors 7.6. Transceiver Toolkit Scripts
7.1. F-Tile Transceiver Toolkit GUI x
7.1.1. Collection View
7.2. F-Tile Transceiver Debugging Flow Walkthrough x
7.2.1. Modifying the Design to Enable F-Tile Transceiver Debug 7.2.2. Programming the Design into an Intel FPGA 7.2.3. Loading the Design to the Transceiver Toolkit 7.2.4. Creating Transceiver Links 7.2.5. Running BER Tests 7.2.6. Running Eye Viewer Tests 7.2.7. Running Link Optimization Tests 7.2.8. Checking FEC Statistics 7.2.9. Vertical Bathtub Curve Measurements (VBCM) Data
7.3. Transceiver Toolkit Parameter Settings x
7.3.1. Dashboard
7.4. Using F-Tile Multirate IPs with Transceiver Toolkit x
7.4.1. F-Tile PMA/FEC Direct PHY Multirate Intel FPGA IP 7.4.2. F-Tile Ethernet Multirate Intel FPGA IP 7.4.3. Ethernet Subsystem Intel FPGA IP
7.6. Transceiver Toolkit Scripts x
7.6.1. Supported Transceiver Toolkit Scripts 7.6.2. Modifying the Scripts 7.6.3. Script Execution 7.6.4. Example of the Results in Tcl Console
A. Appendix x
A.1. F-Tile Production Revision OPNs A.2. OSC_CLK_1 QSF Assignment Requirement
1. F-Tile Overview
2. F-Tile Architecture
3. Implementing the F-Tile PMA/FEC Direct PHY Intel® FPGA IP
4. Implementing the F-Tile Reference and System PLL Clocks Intel® FPGA IP
5. F-Tile PMA/FEC Direct PHY Design Implementation
6. Supported Tools
7. Debugging F-Tile Transceiver Links
8. F-Tile Architecture and PMA and FEC Direct PHY IP User Guide Archives
9. Document Revision History for the F-Tile Architecture and PMA and FEC Direct PHY IP User Guide
A. Appendix

3.5. Bit Mapping for PMA and FEC Mode PHY TX and RX Datapath

The tx_parallel_data bit and rx_parallel_data bit width depends on the PMA width and Number of PMA lanes IP parameters. Use the following equation to determine the total tx_parallel_data or rx_parallel_data bit width:

29

Total tx_parallel_data or rx_parallel_data Bit Width Equation: 

tx/rx_parallel_data[(80*N*X)-1:0]

Where:

  • N = Number of PMA lanes value from 1 to 16.
  • X = Number of streams for the PMA configuration. Depending on PMA width, X can be 1, 2, or 4.

Refer to Variables Defining Bits for the Interfacing Ports in Port and Signal Reference for full variable definitions.

The tx/rx_parallel_data signals include the valid parallel data bits and other functionality bits, such as the data valid bit, the write enable for TX core interface FIFO in elastic mode bit, the RX deskew bit, and the alignment marker bits (for FEC mode). These signals travel to and from the FPGA fabric to the F-tile, and are clocked by the same parallel clock. This parallel clock can be a PMA clock or System PLL clock.

Example 1: Total tx/rx_parallel_data Bit Width with 2 PMA Lanes (N=2) and 8-bit PMA Width (X=1) 

tx_parallel_data [(80*2*1)-1:0] = tx_parallel_data [159:0]
rx_parallel_data [(80*2*1)-1:0] = rx_parallel_data [159:0]

Example 2: Total tx/rx_parallel_data Bit Width with 4 PMA Lanes (N=4) and 64-bit PMA Width (X=2) 

tx_parallel_data [(80*4*2)-1:0] = tx_parallel_data [639:0]
rx_parallel_data [(80*4*2)-1:0] = rx_parallel_data [639:0]

Parallel Data Mapping information for TX and RX

If the PMA width is less than or equal to 32, D=PMA width.

If the PMA width is 64 or 128, D=32.

The lower case x is defined as x=0 to X-1. For a given lane, n and given stream x, you can calculate the TX and RX parallel data information according to the following tables:

Table 58.  PMA Direct Mode TX Parallel Data Information Calculations (Enable Double width transfer = 1)
TX Parallel Data MSB LSB
Write Enable for TX Core FIFO in Elastic Mode 30 79 + (80 * x) +(80 *n * X)
TX Data (Upper Data bits) (40 + D-1) + (80 * x) + (80 *n * X) 40 + (80 * x) + (80 *n * X)
TX PMA Interface Data Valid Bit 31 32 38 + (80 * x) + (80 *n * X)
TX Data (Lower Data bits) D-1 + (80 * x) + (80 *n * X) 0 + (80 * x) +(80 *n * X)
Table 59.  PMA Direct Mode RX Parallel Data Information Calculations (Enable Double width transfer = 1)
RX Parallel Data MSB LSB
Data valid for RX Core FIFO in Elastic Mode 33 79 + (80 * x) + (80 *n * X)
RX Deskew 34 78 + (80 * x) + (80 *n * X)
RX Data (Upper Data bits) (40 + D-1) + (80 * x) + (80 *n * X ) 40 + (80 * x) + (80 *n * X)
RX PMA Interface Data Valid Bit 29 38 + (80 * x) + (80 *n * X)
RX Data (Lower Data bits) D-1 + (80 * x) + (80 *n * X) 0 + (80 * x) + (80 *n * X)
Table 60.  PMA Direct Mode TX Parallel Data Information Calculations (Enable Double width transfer = 0)
TX Parallel Data MSB LSB
Write Enable for TX Core FIFO in Elastic Mode 33 79 + (80 *n)
TX PMA Interface Data Valid Bit 29 30 38 + (80 *n)
TX Data D-1 + (80 *n) 0 + (80 *n)
Table 61.  PMA Direct Mode RX Parallel Data Information Calculations (Enable Double width transfer = 0)
RX Parallel Data MSB LSB
Data valid for RX Core FIFO in Elastic Mode 33 79 + (80 *n)
RX PMA Interface Data Valid Bit 29 38 + (80 *n)
RX Data D-1 + (80 *n) 0 + (80 *n)
Table 62.  FEC Direct Mode TX Parallel Data Information Calculations (Enable Double width transfer = 1)
TX Parallel Data MSB LSB
Alignment Marker 35 77 + (80 * x) +(80 *n * X)
TX Data (Upper 33 bits) 72 + (80 * x) + (80 *n * X) 40 + (80 * x) + (80 *n * X)
TX PMA Interface Data Valid Bit 29 30 38 + (80 * x) + (80 *n * X)
Alignment Marker 33 37 + (80 * x) + (80 *n * X)
TX Data (Lower 31 bits) 32 + (80 * x) + (80 *n * X) 2 + (80 * x) + (80 *n * X)
Sync Head 1 + (80 * x) + (80 *n * X) 0 + (80 * x) + (80 *n * X)
Table 63.  FEC Direct Mode RX Parallel Data Information Calculations (Enable Double width transfer = 1)
RX Parallel Data MSB LSB
RX Deskew 36 78 + (80 * x) + (80 *n * X)
RX Data (Upper 33 bits) 72 + (80 * x) + (80 *n * X) 40 + (80 * x) + (80 *n * X)
RX PMA Interface Data Valid Bit 29 37 38
Alignment Marker 32 37
RX Data (Lower 31 bits) 32 + (80 * x) + (80 *n * X) 2 + (80 * x) + (80 *n * X)
Sync Head 1 + (80 * x) + (80 *n * X) 0 + (80 * x) + (80 *n * X)

Section Content
Parallel Data Mapping Information
TX and RX Parallel Data Mapping Information for Different Configurations
Example of TX Parallel Data for PMA Width = 8, 10, 16, 20, 32 (X=1)
Example of TX Parallel Data for PMA width = 64 (X=2)
Example of TX Parallel Data for PMA width = 64 (X=2) for FEC Direct Mode

29 This section explains the bit mapping of TX and RX parallel data if the Provide separate interface for each PMA option is disabled. If the Provide separate interface for each PMA option is enabled, refer to the introduction of Signal and Port Reference to view the bit mapping differences.
30 Applicable only when using PMA clocking mode only and when TX/RX core FIFO is in elastic mode.
31 Applicable only when using System PLL clocking mode.
32 For all bonded configurations, all TX PMA Interface Data Valid bits must be asserted at the same cycle of tx_coreclkin clock.
33 Split Interface for datapath Memory mapped Avalon interface only supported for PMA Direct mode.
34 Applicable only when using PAM4 and X=2 or 4
35 The two alignment markers in this table must be driven together by the same signal.
36 Applicable only when using NRZ/PAM4 when X=2 or 4 or N > 1
37 Only one per system
Level Two Title