JESD204B Intel® FPGA IP User Guide

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ID 683442
Date 5/05/2023
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Document Table of Contents
Document Table of Contents x
1. JESD204B IP Quick Reference 2. About the JESD204B Intel® FPGA IP 3. Getting Started 4. JESD204B IP Functional Description 5. JESD204B IP Deterministic Latency Implementation Guidelines 6. JESD204B IP Debug Guidelines 7. JESD204B Intel® FPGA IP User Guide Archives 8. Document Revision History for the JESD204B Intel® FPGA IP User Guide
2. About the JESD204B Intel® FPGA IP x
2.1. Release Information 2.2. Device Family Support 2.3. Datapath Modes 2.4. IP Variation 2.5. JESD204B IP Configuration 2.6. Channel Bonding 2.7. Performance and Resource Utilization
2.5. JESD204B IP Configuration x
2.5.1. Run-Time Configuration
3. Getting Started x
3.1. Introduction to Intel® FPGA IP Cores 3.2. Installing and Licensing Intel® FPGA IP Cores 3.3. Intel® FPGA IP Evaluation Mode 3.4. Upgrading IP Cores 3.5. IP Catalog and Parameter Editor 3.6. Design Walkthrough 3.7. JESD204B Design Examples 3.8. JESD204B IP Design Considerations 3.9. JESD204B Intel® FPGA IP Parameters 3.10. JESD204B IP Component Files 3.11. JESD204B IP Testbench
3.6. Design Walkthrough x
3.6.1. Creating a New Intel® Quartus® Prime Project 3.6.2. Parameterizing and Generating the IP 3.6.3. Compiling the JESD204B IP Core Design 3.6.4. Programming an FPGA Device
3.8. JESD204B IP Design Considerations x
3.8.1. Integrating the JESD204B IP in Platform Designer 3.8.2. Pin Assignments 3.8.3. Adding External Transceiver PLLs 3.8.4. Timing Constraints For Input Clocks
3.11. JESD204B IP Testbench x
3.11.1. Generating and Simulating the IP Testbench 3.11.2. Testbench Simulation Flow
3.11.1. Generating and Simulating the IP Testbench x
3.11.1.1. Generating the Testbench Simulation Model 3.11.1.2. Simulating the IP Testbench
4. JESD204B IP Functional Description x
4.1. Transmitter 4.2. Receiver 4.3. Operation 4.4. Clocking Scheme 4.5. Reset Scheme 4.6. Signals 4.7. Registers
4.1. Transmitter x
4.1.1. TX Data Link Layer 4.1.2. TX PHY Layer
4.1.1. TX Data Link Layer x
4.1.1.1. TX CGS 4.1.1.2. TX ILAS 4.1.1.3. User Data Phase
4.2. Receiver x
4.2.1. RX Data Link Layer 4.2.2. RX PHY Layer
4.2.1. RX Data Link Layer x
4.2.1.1. RX CGS 4.2.1.2. Frame Synchronization 4.2.1.3. Frame Alignment 4.2.1.4. Lane Alignment 4.2.1.5. ILAS Data 4.2.1.6. Initial Lane Synchronization
4.3. Operation x
4.3.1. Operating Modes 4.3.2. Scrambler/Descrambler 4.3.3. SYNC_N Signal 4.3.4. Link Reinitialization 4.3.5. Link Startup Sequence 4.3.6. Error Reporting Through SYNC_N Signal
4.3.1. Operating Modes x
4.3.1.1. Subclass 0 Operating Mode 4.3.1.2. Subclass 1 Operating Mode 4.3.1.3. Subclass 2 Operating Mode
4.4. Clocking Scheme x
4.4.1. Device Clock 4.4.2. Link Clock 4.4.3. Local MultiFrame Clock 4.4.4. Clock Correlation 4.4.5. Transceiver Calibration Clock Source
4.5. Reset Scheme x
4.5.1. Reset Sequence 4.5.2. ADC–FPGA Subsystem Reset Sequence 4.5.3. FPGA–DAC Subsystem Reset Sequence
4.6. Signals x
4.6.1. Transmitter Signals 4.6.2. Receiver Signals
4.7. Registers x
4.7.1. Register Access Type Convention 4.7.2. Transmitter Registers 4.7.3. Receiver Registers
5. JESD204B IP Deterministic Latency Implementation Guidelines x
5.1. Constraining Incoming SYSREF Signal 5.2. Programmable RBD Offset 5.3. Programmable LMFC Offset 5.4. Maintaining Deterministic Latency during Link Reinitialization
6. JESD204B IP Debug Guidelines x
6.1. Clocking Scheme 6.2. JESD204B Parameters 6.3. SPI Programming 6.4. Converter and FPGA Operating Conditions 6.5. Signal Polarity and FPGA Pin Assignment 6.6. Creating a Signal Tap Debug File to Match Your Design Hierarchy 6.7. Debugging JESD204B Link Using System Console
6.6. Creating a Signal Tap Debug File to Match Your Design Hierarchy x
6.6.1. Removing Irrelevant Signals and Adding E-Tile PHY Signals
1. JESD204B IP Quick Reference
2. About the JESD204B Intel® FPGA IP
3. Getting Started
4. JESD204B IP Functional Description
5. JESD204B IP Deterministic Latency Implementation Guidelines
6. JESD204B IP Debug Guidelines
7. JESD204B Intel® FPGA IP User Guide Archives
8. Document Revision History for the JESD204B Intel® FPGA IP User Guide

4.4.3. Local MultiFrame Clock

The Local MultiFrame Clock (LMFC) is a counter generated from the link clock and depends on the F and K parameter.

The K parameter must be set between 1 to 32 and meet the requirement of at least a minimum of 17 octets and a maximum of 1024 octets in a single multiframe. In a 32-bit architecture, the K × F must also be in the order of four.

In a Subclass 1 deterministic latency system, the SYSREF frequency is distributed to the devices to align them in the system. The SYSREF resets the internal LMFC clock edge when the sampled SYSREF signal's rising edge transition from 0 to 1. Due to source synchronous signaling of SYSREF with respect to the device clock sampling (provided from the clock chip), the JESD204B IP core does not directly use the device clock to sample SYSREF but instead uses the link clock to sample SYSREF. Therefore, the Intel® FPGA PLL IP core that provides the link clock must to be in normal mode to phase-compensate the link clock to the device clock.

Based on hardware testing, to get a fixed latency, at least 32 octets are recommended in an LMFC period so that there is a margin to tune the RBD release opportunity to compensate any lane-to-lane deskew across multiple resets. If F = 1, then K = 32 is optimal as it provides enough margin for system latency variation. If F = 2, then K = 16 and above (18/20/22/24/26/28/30/32) is sufficient to compensate lane-to-lane deskew.

The JESD204B IP core implements the local multiframe clock as a counter that increments in link clock counts. The local multiframe clock counter is equal to (F × K/4) in link clock as units. The rising edge of SYSREF resets the local multiframe clock counter to 0. There are two CSR bits that controls SYSREF sampling.

  • csr_sysref_singledet—resets the local multiframe clock counter once and automatically cleared after SYSREF is sampled. This register also prevents CGS exit to bypass SYSREF sampling.
  • csr_sysref_alwayson—resets the local multiframe clock counter at every rising edge of SYSREF that it detects. This register also enables the SYSREF period checker. If the provided SYSREF period violates the F and K parameter, an interrupt is triggered. However, this register does not prevent CGS-SYSREF race condition.

The following conditions occur if both CSR bits are set:

  • resets the local multiframe clock counter at every rising edge of SYSREF.
  • prevents CGS-SYSREF race condition.
  • checks SYSREF period.
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