AN 846: Intel® Stratix® 10 Forward Error Correction

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ID 683805
Date 7/02/2018
Public
Document Table of Contents
Document Table of Contents x
1. Introduction 2. Necessity of Error Correction 3. FEC Selection 4. FEC in Intel® Stratix® 10 H-Tile Devices 5. FEC in Intel® Stratix® 10 E-Tile Devices 6. FEC Implementation Using the E-Tile Channel Placement Tool 7. FEC in Practical Application 8. Hardware Results 9. Document Revision History for AN 846: Intel® Stratix® 10 Forward Error Correction
2. Necessity of Error Correction x
2.1. Solutions to Transmission Errors 2.2. Error Correction Codes 2.3. What is FEC?
2.1. Solutions to Transmission Errors x
2.1.1. Parity and Cyclic Redundancy Check 2.1.2. Error Correction Code (ECC) Block Coding
2.3. What is FEC? x
2.3.1. FEC Definitions
3. FEC Selection x
3.1. Key Considerations when Choosing a FEC
4. FEC in Intel® Stratix® 10 H-Tile Devices x
4.1. Fire Code (802.3ap, 10GBASE-KR)
4.1. Fire Code (802.3ap, 10GBASE-KR) x
4.1.1. FEC Block Format 4.1.2. FEC Block Composition 4.1.3. FEC Sublayer for BASE-R PHYs 4.1.4. L-Tile/H-Tile Implementation
4.1.4. L-Tile/H-Tile Implementation x
4.1.4.1. Transcode Encoder 4.1.4.2. KR FEC Encoder 4.1.4.3. KR FEC Scrambler 4.1.4.4. KR FEC TX Gearbox 4.1.4.5. KR FEC RX Gearbox 4.1.4.6. Transcode Decoder
5. FEC in Intel® Stratix® 10 E-Tile Devices x
5.1. Types of RS-FEC 5.2. 100GBASE-KR4 5.3. 100GBASE-KP4 5.4. FEC Decoders 5.5. Specifications 5.6. Functions Within the RS-FEC Sublayer
5.1. Types of RS-FEC x
5.1.1. RS (528, 514, t = 7, m = 10) 5.1.2. RS (544, 514, t = 15, m = 10) 5.1.3. Supported RS-FEC Modes in E-Tile Devices
5.2. 100GBASE-KR4 x
5.2.1. 100GBASE-KR4 Mapping (IEEE802.3bj Clause 91)
5.3. 100GBASE-KP4 x
5.3.1. 100GBASE-KP4 Mapping (IEEE802.3bj Clause 91)
5.6. Functions Within the RS-FEC Sublayer x
5.6.1. Lane Block Synchronization 5.6.2. Alignment Lock and Deskew 5.6.3. Lane Re-order 5.6.4. Alignment Marker Removal 5.6.5. 64B/66B to 256B/257B Transcoder
7. FEC in Practical Application x
7.1. Datacenter Applications Scenario
8. Hardware Results x
8.1. Test Design 8.2. Test Setup 8.3. Insertion Loss Plots 8.4. FEC Statistics Tool 8.5. Hardware Data 8.6. Comparison to the Specification 8.7. References
1. Introduction
2. Necessity of Error Correction
3. FEC Selection
4. FEC in Intel® Stratix® 10 H-Tile Devices
5. FEC in Intel® Stratix® 10 E-Tile Devices
6. FEC Implementation Using the E-Tile Channel Placement Tool
7. FEC in Practical Application
8. Hardware Results
9. Document Revision History for AN 846: Intel® Stratix® 10 Forward Error Correction

5.5. Specifications

The IEEE802.3ap specification defines an insertion loss and return loss of 25 dB at 5.15625 GHz. The 1e-12 BER requirement is a system specification that is met with or without FEC.

The IEEE802.3bj specification specifies 100GBASE-KR4 for 100 Gbps operation using NRZ over four differential pairs where the insertion loss does not exceed 35 dB at 12.9 GHz. 100GBASE-KR4 uses:

  • The PCS defined in Clause 82
  • The RS-FEC defined in Clause 91
  • The PMA defined in Clause 83
  • The PMD defined in Clause 93

IEEE802.3bj also specifies 100GBASE-KP4 for 100 Gbps operation using PAM4 over two differential pairs where the insertion loss does not exceed 33 dB at 7 GHz. 100GBASE-KP4 uses:

  • The PCS defined in Clause 82
  • The RS-FEC defined in Clause 91
  • The PMA and PMD defined in Clause 94

The CEI 56G long reach (LR) specification discusses multiple FECs, but the standard is KP4 FEC with PAM4. The 1e-15 BER requirement is a system specification met with FEC.

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