MAX® 10 High-Speed LVDS I/O User Guide

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ID 683760
Date 3/10/2025
Public
Document Table of Contents
Document Table of Contents x
1. MAX® 10 High-Speed LVDS I/O Overview 2. MAX® 10 High-Speed LVDS Architecture and Features 3. MAX® 10 LVDS Transmitter Design 4. MAX® 10 LVDS Receiver Design 5. MAX® 10 LVDS Transmitter and Receiver Design 6. MAX® 10 High-Speed LVDS Board Design Considerations 7. Soft LVDS Intel® FPGA IP Core References 8. MAX® 10 High-Speed LVDS I/O User Guide Archives 9. Document Revision History for the MAX® 10 High-Speed LVDS I/O User Guide
1. MAX® 10 High-Speed LVDS I/O Overview x
1.1. Soft LVDS Implementation Overview
2. MAX® 10 High-Speed LVDS Architecture and Features x
2.1. MAX® 10 LVDS Channels Support 2.2. MAX® 10 LVDS SERDES I/O Standards Support 2.3. MAX® 10 High-Speed LVDS Circuitry 2.4. MAX® 10 High-Speed LVDS I/O Location 2.5. Differential I/O Pins in Low Speed Region
3. MAX® 10 LVDS Transmitter Design x
3.1. High-Speed I/O Transmitter Circuitry 3.2. LVDS Transmitter Programmable I/O Features 3.3. LVDS Transmitter I/O Termination Schemes 3.4. LVDS Transmitter FPGA Design Implementation 3.5. LVDS Transmitter Debug and Troubleshooting
3.2. LVDS Transmitter Programmable I/O Features x
3.2.1. Programmable Pre-Emphasis 3.2.2. Programmable Differential Output Voltage
3.3. LVDS Transmitter I/O Termination Schemes x
3.3.1. Emulated LVDS External Termination 3.3.2. Sub-LVDS Transmitter External Termination 3.3.3. SLVS Transmitter External Termination 3.3.4. Emulated RSDS, Emulated Mini-LVDS, and Emulated PPDS Transmitter External Termination
3.4. LVDS Transmitter FPGA Design Implementation x
3.4.1. Soft LVDS IP Core in Transmitter Mode 3.4.2. High-Speed I/O Timing Budget 3.4.3. Guidelines: LVDS Transmitter Channels Placement 3.4.4. Guidelines: LVDS Channels PLL Placement 3.4.5. Guidelines: LVDS Transmitter Logic Placement 3.4.6. Guidelines: Enable LVDS Pre-Emphasis for E144 Package
3.4.1. Soft LVDS IP Core in Transmitter Mode x
3.4.1.1. PLL Source Selection for Soft LVDS IP Core 3.4.1.2. Guidelines: LVDS TX Interface Using External PLL 3.4.1.3. Initializing the Soft LVDS IP Core
3.4.1.1. PLL Source Selection for Soft LVDS IP Core x
3.4.1.1.1. Instantiate Soft LVDS IP Core with Internal PLL 3.4.1.1.2. Instantiate Soft LVDS IP Core with External PLL
3.4.1.2. Guidelines: LVDS TX Interface Using External PLL x
3.4.1.2.1. ALTPLL Signal Interface with Soft LVDS Transmitter 3.4.1.2.2. Determining External PLL Clock Parameters for Soft LVDS Transmitter
3.4.2. High-Speed I/O Timing Budget x
3.4.2.1. Transmitter Channel-to-Channel Skew
3.5. LVDS Transmitter Debug and Troubleshooting x
3.5.1. Perform RTL Simulation Before Hardware Debug 3.5.2. Geometry-Based and Physics-Based I/O Rules
4. MAX® 10 LVDS Receiver Design x
4.1. High-Speed I/O Receiver Circuitry 4.2. LVDS Receiver I/O Termination Schemes 4.3. LVDS Receiver FPGA Design Implementation 4.4. LVDS Receiver Debug and Troubleshooting
4.1. High-Speed I/O Receiver Circuitry x
4.1.1. Soft Deserializer 4.1.2. Data Realignment Block (Bit Slip)
4.2. LVDS Receiver I/O Termination Schemes x
4.2.1. LVDS, 1.8 V LVDS, Mini-LVDS, and RSDS Receiver External Termination 4.2.2. SLVS Receiver External Termination 4.2.3. Sub-LVDS Receiver External Termination 4.2.4. TMDS Receiver External Termination 4.2.5. HiSpi Receiver External Termination 4.2.6. LVPECL External Termination
4.3. LVDS Receiver FPGA Design Implementation x
4.3.1. Soft LVDS IP Core in Receiver Mode 4.3.2. High-Speed I/O Timing Budget 4.3.3. Guidelines: Floating LVDS Input Pins 4.3.4. Guidelines: LVDS Receiver Channels Placement 4.3.5. Guidelines: LVDS Channels PLL Placement 4.3.6. Guidelines: LVDS Receiver Logic Placement
4.3.1. Soft LVDS IP Core in Receiver Mode x
4.3.1.1. PLL Source Selection for Soft LVDS IP Core 4.3.1.2. Guidelines: LVDS RX Interface Using External PLL 4.3.1.3. Initializing the Soft LVDS IP Core 4.3.1.4. Guidelines: Applying Input Delay Constraint for LVDS SERDES Receiver
4.3.1.1. PLL Source Selection for Soft LVDS IP Core x
4.3.1.1.1. Instantiate Soft LVDS IP Core with Internal PLL 4.3.1.1.2. Instantiate Soft LVDS IP Core with External PLL
4.3.1.2. Guidelines: LVDS RX Interface Using External PLL x
4.3.1.2.1. ALTPLL Signal Interface with Soft LVDS Receiver 4.3.1.2.2. Determining External PLL Clock Parameters for Soft LVDS Receiver
4.3.2. High-Speed I/O Timing Budget x
4.3.2.1. Receiver Input Skew Margin 4.3.2.2. Guidelines: LVDS Receiver Timing Constraints
4.3.2.1. Receiver Input Skew Margin x
4.3.2.1.1. RSKM Equation 4.3.2.1.2. Example: RSKM Calculation
4.4. LVDS Receiver Debug and Troubleshooting x
4.4.1. Perform RTL Simulation Before Hardware Debug 4.4.2. Geometry-Based and Physics-Based I/O Rules
5. MAX® 10 LVDS Transmitter and Receiver Design x
5.1. Transmitter–Receiver Interfacing 5.2. LVDS Transmitter and Receiver FPGA Design Implementation 5.3. LVDS Transmitter and Receiver Debug and Troubleshooting
5.2. LVDS Transmitter and Receiver FPGA Design Implementation x
5.2.1. LVDS Transmitter and Receiver PLL Sharing Implementation 5.2.2. Initializing the Soft LVDS IP Core
5.3. LVDS Transmitter and Receiver Debug and Troubleshooting x
5.3.1. Perform RTL Simulation Before Hardware Debug 5.3.2. Geometry-Based and Physics-Based I/O Rules
6. MAX® 10 High-Speed LVDS Board Design Considerations x
6.1. Guidelines: Improve Signal Quality 6.2. Guidelines: Control Channel-to-Channel Skew 6.3. Guidelines: Determine Board Design Constraints 6.4. Guidelines: Perform Board Level Simulations
7. Soft LVDS Intel® FPGA IP Core References x
7.1. Soft LVDS Intel® FPGA IP Parameter Settings 7.2. Soft LVDS Intel® FPGA IP Interface Signals
1. MAX® 10 High-Speed LVDS I/O Overview
2. MAX® 10 High-Speed LVDS Architecture and Features
3. MAX® 10 LVDS Transmitter Design
4. MAX® 10 LVDS Receiver Design
5. MAX® 10 LVDS Transmitter and Receiver Design
6. MAX® 10 High-Speed LVDS Board Design Considerations
7. Soft LVDS Intel® FPGA IP Core References
8. MAX® 10 High-Speed LVDS I/O User Guide Archives
9. Document Revision History for the MAX® 10 High-Speed LVDS I/O User Guide

3.2.1. Programmable Pre-Emphasis

The differential output voltage (VOD) setting and the output impedance of the driver set the output current limit of a high-speed transmission signal. At a high frequency, the slew rate may not be fast enough to reach the full VOD level before the next edge, producing pattern-dependent jitter. Pre-emphasis momentarily boosts the output current during switching to increase the output slew rate.

Pre-emphasis increases the amplitude of the high-frequency component of the output signal. This increase compensates for the frequency-dependent attenuation along the transmission line.

The overshoot introduced by the extra current occurs only during change of state switching. This overshoot increases the output slew rate but does not ring, unlike the overshoot caused by signal reflection. The amount of pre-emphasis required depends on the attenuation of the high-frequency component along the transmission line.

Figure 7. LVDS Output with Programmable Pre-Emphasis


Table 4.   Quartus® Prime Software Assignment for Programmable Pre-Emphasis
Field Assignment
To tx_out
Assignment name Programmable Pre-emphasis
Allowed values 0 (disabled), 1 (enabled). Default is 1.
Level Two Title