External Memory Interfaces (EMIF) IP User Guide: Agilex™ 5 FPGAs and SoCs

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ID 817467
Date 4/01/2024
Public
Document Table of Contents
Document Table of Contents x
1. About the External Memory Interfaces Agilex™ 5 FPGA IP 2. Agilex™ 5 FPGA EMIF IP – Introduction 3. Agilex™ 5 FPGA EMIF IP – Product Architecture 4. Agilex™ 5 FPGA EMIF IP – End-User Signals 5. Agilex™ 5 FPGA EMIF IP – Simulating Memory IP 6. Intel® Agilex™ 5 FPGA EMIF IP - DDR4 Support 7. Intel® Agilex™ 5 FPGA EMIF IP - LPDDR4 Support 8. Intel® Agilex™ 5 FPGA EMIF IP - LPDDR5 Support 9. Agilex™ 5 FPGA EMIF IP – Timing Closure 10. Agilex™ 5 FPGA EMIF IP – Controller Optimization 11. Agilex™ 5 FPGA EMIF IP – Debugging 12. Document Revision History for External Memory Interfaces (EMIF) IP User Guide
1. About the External Memory Interfaces Agilex™ 5 FPGA IP x
1.1. Release Information
2. Agilex™ 5 FPGA EMIF IP – Introduction x
2.1. Agilex™ 5 EMIF IP Protocol and Feature Support 2.2. Agilex™ 5 EMIF IP Design Flow
2.2. Agilex™ 5 EMIF IP Design Flow x
2.2.1. Agilex™ 5 EMIF IP Design Checklist
3. Agilex™ 5 FPGA EMIF IP – Product Architecture x
3.1. Agilex™ 5 EMIF Architecture: Protocol and Maximum Interface Width Support 3.2. Agilex™ 5 EMIF Architecture: Introduction 3.3. Agilex™ 5 EMIF Sequencer 3.4. Agilex™ 5 EMIF Controller 3.5. Agilex™ 5 EMIF IP for Hard Processor Subsystem (HPS)
3.2. Agilex™ 5 EMIF Architecture: Introduction x
3.2.1. Agilex™ 5 EMIF Architecture: I/O Subsystem 3.2.2. Agilex™ 5 EMIF Architecture: I/O SSM 3.2.3. Agilex™ 5 EMIF Architecture: HSIO Bank 3.2.4. Agilex™ 5 EMIF Architecture: I/O Lane 3.2.5. Agilex™ 5 EMIF Architecture: Input DQS Clock Tree 3.2.6. Agilex™ 5 EMIF Architecture: PHY Clock Tree 3.2.7. Agilex™ 5 EMIF Architecture: PLL Reference Clock Networks 3.2.8. Agilex™ 5 EMIF Architecture: Clock Phase Alignment 3.2.9. User Clock in Different Core Access Modes
3.2.3. Agilex™ 5 EMIF Architecture: HSIO Bank x
3.2.3.1. Pin Placement 3.2.3.2. HSIO Sub-Bank Usage
3.3. Agilex™ 5 EMIF Sequencer x
3.3.1. Agilex™ 5 Mailbox Structure and Register Definitions
3.3.1. Agilex™ 5 Mailbox Structure and Register Definitions x
3.3.1.1. Mailbox Supported Commands 3.3.1.2. Mailbox Command Definitions
3.4. Agilex™ 5 EMIF Controller x
3.4.1. Hard Memory Controller
3.4.1. Hard Memory Controller x
3.4.1.1. Hard Memory Controller Features
4. Agilex™ 5 FPGA EMIF IP – End-User Signals x
4.1. Agilex™ 5 FPGA EMIF IP Interfaces for DDR4 4.2. Agilex™ 5 FPGA EMIF IP Interfaces for LPDDR4 4.3. Agilex™ 5 FPGA EMIF IP Interfaces for LPDDR5 4.4. Agilex™ 5 FPGA EMIF IP Interfaces for EMIF Calibration Component
4.1. Agilex™ 5 FPGA EMIF IP Interfaces for DDR4 x
4.1.1. ref_clk for EMIF 4.1.2. core_init_n for EMIF 4.1.3. usr_async_clk for EMIF 4.1.4. usr_clk for EMIF 4.1.5. usr_rst_n for EMIF 4.1.6. s0_axi4 for EMIF 4.1.7. mem for EMIF 4.1.8. oct for EMIF
4.2. Agilex™ 5 FPGA EMIF IP Interfaces for LPDDR4 x
4.2.1. ref_clk for EMIF 4.2.2. core_init_n for EMIF 4.2.3. usr_async_clk for EMIF 4.2.4. usr_clk for EMIF 4.2.5. usr_rst_n for EMIF 4.2.6. s0_axi4 for EMIF 4.2.7. mem for EMIF 4.2.8. oct for EMIF
4.3. Agilex™ 5 FPGA EMIF IP Interfaces for LPDDR5 x
4.3.1. ref_clk for EMIF 4.3.2. core_init_n for EMIF 4.3.3. usr_async_clk for EMIF 4.3.4. usr_clk for EMIF 4.3.5. usr_rst_n for EMIF 4.3.6. s0_axi4 for EMIF 4.3.7. oct for EMIF
4.4. Agilex™ 5 FPGA EMIF IP Interfaces for EMIF Calibration Component x
4.4.1. s0_axi4lite_clk for EMIF 4.4.2. s0_axi4lite_rst_n for EMIF 4.4.3. s0_axil for EMIF
5. Agilex™ 5 FPGA EMIF IP – Simulating Memory IP x
5.1. Simulation Walkthrough
5.1. Simulation Walkthrough x
5.1.1. Calibration 5.1.2. Simulation Scripts 5.1.3. Functional Simulation with Verilog HDL 5.1.4. Simulating the Design Example
6. Intel® Agilex™ 5 FPGA EMIF IP - DDR4 Support x
6.1. Intel® Agilex™ 5 FPGA EMIF IP Parameters for DDR4 6.2. Agilex™ 5 FPGA EMIF IP Pin and Resource Planning 6.3. Agilex™ 5 EMIF Pin Swapping Guidelines 6.4. DDR4 Layout Design Guidelines
6.1. Intel® Agilex™ 5 FPGA EMIF IP Parameters for DDR4 x
6.1.1. Agilex™ 5 FPGA EMIF IP Parameter for DDR4 6.1.2. Intel Agilex 5 FPGA EMIF Memory Device Description IP (DDR4) Parameter Descriptions
6.2. Agilex™ 5 FPGA EMIF IP Pin and Resource Planning x
6.2.1. Intel® Agilex™ 5 FPGA EMIF IP Resources 6.2.2. Pin Guidelines for Intel® Agilex™ 5 FPGA EMIF IP 6.2.3. Pin Placements for Intel® Agilex™ 5 FPGA DDR4 EMIF IP
6.2.1. Intel® Agilex™ 5 FPGA EMIF IP Resources x
6.2.1.1. OCT 6.2.1.2. PLL
6.2.2. Pin Guidelines for Intel® Agilex™ 5 FPGA EMIF IP x
6.2.2.1. Intel® Agilex™ 5 FPGA EMIF IP Pin and Resource Planning
6.2.2.1. Intel® Agilex™ 5 FPGA EMIF IP Pin and Resource Planning x
6.2.2.1.1. Intel® Agilex™ 5 FPGA EMIF IP Interface Pins 6.2.2.1.2. Estimating Pin Requirements 6.2.2.1.3. Maximum Number of Interfaces
6.2.3. Pin Placements for Intel® Agilex™ 5 FPGA DDR4 EMIF IP x
6.2.3.1. Address and Command Pin Placement for DDR4 6.2.3.2. DDR4 Data Width Mapping 6.2.3.3. General Guidelines 6.2.3.4. Specific Pin Connection Requirements 6.2.3.5. Command and Address Signals 6.2.3.6. Clock Signals 6.2.3.7. Data, Data Strobes, DM/DBI, and Optional ECC Signals
6.3. Agilex™ 5 EMIF Pin Swapping Guidelines x
6.3.1. DDR4 Byte Lane Swapping 6.3.2. DDR4 Address and Command and CLK Lane 6.3.3. DDR4 Interface x8 Data Lane 6.3.4. DDR4 Interface x4 Data Lane
6.4. DDR4 Layout Design Guidelines x
6.4.1. DDR4 PCB Stackup and Design Considerations 6.4.2. DDR4 General Design Considerations 6.4.3. DDR4 Routing Guidelines - Memory-Down (Discrete) Topologies
6.4.3. DDR4 Routing Guidelines - Memory-Down (Discrete) Topologies x
6.4.3.1. 1 Rank x 8 Discrete (Memory Down) Topology 6.4.3.2. 1 Rank x 16 Discrete (Memory Down) Topology 6.4.3.3. VREF_CA/RESET Signal Routing Guidelines for 1 Rank x 8 and 1 Rank x 16 Discrete (Memory Down) Topology 6.4.3.4. Skew Matching Guidelines for DDR4 (Memory Down) Discrete Configurations 6.4.3.5. Power Delivery Recommendation for DDR4 Discrete Configurations 6.4.3.6. DDR4 Simulation Strategy
7. Intel® Agilex™ 5 FPGA EMIF IP - LPDDR4 Support x
7.1. Intel® Agilex™ 5 FPGA EMIF IP Parameters for LPDDR4 7.2. Intel® Agilex™ 5 FPGA EMIF IP Pin and Resource Planning 7.3. LPDDR4 Layout Design Guidelines
7.1. Intel® Agilex™ 5 FPGA EMIF IP Parameters for LPDDR4 x
7.1.1. Agilex™ 5 FPGA EMIF IP Parameter for LPDDR4 7.1.2. Intel Agilex 5 FPGA EMIF Memory Device Description IP (LPDDR4) Parameter Descriptions
7.2. Intel® Agilex™ 5 FPGA EMIF IP Pin and Resource Planning x
7.2.1. Intel® Agilex™ 5 FPGA EMIF IP Interface Pins 7.2.2. Intel® Agilex™ 5 FPGA EMIF IP Resources 7.2.3. Pin Guidelines for Intel® Agilex™ 5 FPGA EMIF IP
7.2.1. Intel® Agilex™ 5 FPGA EMIF IP Interface Pins x
7.2.1.1. Estimating Pin Requirements 7.2.1.2. LPDDR4 Component Options 7.2.1.3. Maximum Number of Interfaces
7.2.2. Intel® Agilex™ 5 FPGA EMIF IP Resources x
7.2.2.1. OCT 7.2.2.2. PLL
7.2.3. Pin Guidelines for Intel® Agilex™ 5 FPGA EMIF IP x
7.2.3.1. General Guidelines 7.2.3.2. Specific Pin Connection Requirements 7.2.3.3. Command and Address Signals 7.2.3.4. Clock Signals 7.2.3.5. Address and Command Pin Placement for LPDDR4 7.2.3.6. Pin Placements for Agilex™ 5 FPGA EMIF IP for LPDDR4 7.2.3.7. Pin Swapping Guidelines
7.3. LPDDR4 Layout Design Guidelines x
7.3.1. LPDDR4 PCB Stackup and Design Considerations 7.3.2. LPDDR4 General Design Considerations 7.3.3. LPDDR4 Interface Design Guidelines
7.3.3. LPDDR4 Interface Design Guidelines x
7.3.3.1. LPDDR4 Discrete Component/Memory Down Topology (up to 32 bits interface) 7.3.3.2. LPDDR4 Simulation Strategy
8. Intel® Agilex™ 5 FPGA EMIF IP - LPDDR5 Support x
8.1. Intel Agilex 5 FPGA EMIF IP Parameters for LPDDR5 8.2. Agilex™ 5 FPGA EMIF IP Pin and Resource Planning 8.3. LPDDR5 Layout Design Guidelines
8.1. Intel Agilex 5 FPGA EMIF IP Parameters for LPDDR5 x
8.1.1. Agilex™ 5 FPGA EMIF IP Parameter for LPDDR5 8.1.2. Intel Agilex 5 FPGA EMIF Memory Device Description IP (LPDDR5) Parameter Descriptions
8.2. Agilex™ 5 FPGA EMIF IP Pin and Resource Planning x
8.2.1. Agilex™ 5 FPGA EMIF IP Interface Pins 8.2.2. Agilex™ 5 FPGA EMIF IP Resources 8.2.3. Pin Guidelines for Agilex™ 5 FPGA EMIF IP 8.2.4. Pin Placements for Intel Agilex 5 FPGA LPDDR5 EMIF IP
8.2.1. Agilex™ 5 FPGA EMIF IP Interface Pins x
8.2.1.1. Estimating Pin Requirements 8.2.1.2. LPDDR5 Component Options 8.2.1.3. Maximum Number of Interfaces
8.2.2. Agilex™ 5 FPGA EMIF IP Resources x
8.2.2.1. OCT 8.2.2.2. PLL
8.2.3. Pin Guidelines for Agilex™ 5 FPGA EMIF IP x
8.2.3.1. General Guidelines - LPDDR5 8.2.3.2. Specific Pin Connection Requirements 8.2.3.3. Command and Address Signals 8.2.3.4. Clock Signals
8.2.4. Pin Placements for Intel Agilex 5 FPGA LPDDR5 EMIF IP x
8.2.4.1. Address and Command Pin Placement for LPDDR5 8.2.4.2. LPDDR5 Data Width Mapping 8.2.4.3. LPDDR5 Byte Lane Swapping
8.3. LPDDR5 Layout Design Guidelines x
8.3.1. LPDDR5 PCB Stackup and Design Considerations 8.3.2. LPDDR5 General Design Considerations General DDR Signal Routing Guideline on PCB DDR FPGA Break Out Routing DDR Differential Signals Routing Ground Plane and Return Path DRAM Break Out in Layout Guideline 8.3.3. LPDDR5 Interface Design Guidelines
8.3.3. LPDDR5 Interface Design Guidelines x
8.3.3.1. LPDDR5 Discrete Component/Memory Down Topology (Single Rank or Dual-Rank) 8.3.3.2. Example of an LPDDR5 Layout on an Intel FPGA Platform Board 8.3.3.3. LPDDR5 Simulation Strategy
9. Agilex™ 5 FPGA EMIF IP – Timing Closure x
9.1. Timing Closure 9.2. Optimizing Timing
9.1. Timing Closure x
9.1.1. Timing Analysis
9.1.1. Timing Analysis x
9.1.1.1. PHY or Core
10. Agilex™ 5 FPGA EMIF IP – Controller Optimization x
10.1. Interface Standard 10.2. Bank Management Efficiency 10.3. Data Transfer 10.4. Improving Controller Efficiency
10.4. Improving Controller Efficiency x
10.4.1. Frequency of Operation 10.4.2. Series of Reads or Writes
11. Agilex™ 5 FPGA EMIF IP – Debugging x
11.1. Interface Configuration Performance Issues 11.2. Functional Issue Evaluation 11.3. Timing Issue Characteristics 11.4. Verifying Memory IP Using the Signal Tap Logic Analyzer 11.5. Generating Traffic with the Test Engine IP 11.6. Guidelines for Developing HDL for Traffic Generator 11.7. Hardware Debugging Guidelines 11.8. Create a Simplified Design that Demonstrates the Same Issue 11.9. Measure Power Distribution Network 11.10. Measure Signal Integrity and Setup and Hold Margin 11.11. Vary Voltage 11.12. Operate at a Lower Speed 11.13. Determine Whether the Issue Exists in Previous Versions of Software 11.14. Determine Whether the Issue Exists in the Current Version of Software 11.15. Try A Different PCB 11.16. Try Other Configurations 11.17. Debugging Checklist 11.18. Categorizing Hardware Issues 11.19. Signal Integrity Issues 11.20. Characteristics of Signal Integrity Issues 11.21. Evaluating Signal Integrity Issues 11.22. Skew 11.23. Crosstalk 11.24. Power System 11.25. Clock Signals 11.26. Address and Command Signals 11.27. Read Data Valid Window and Eye Diagram 11.28. Write Data Valid Window and Eye Diagram 11.29. Hardware and Calibration Issues 11.30. Memory Timing Parameter Evaluation 11.31. Verify that the Board Has the Correct Memory Component or DIMM Installed
11.1. Interface Configuration Performance Issues x
11.1.1. Interface Configuration Bottleneck and Efficiency Issues
11.2. Functional Issue Evaluation x
11.2.1. Intel® IP Memory Model 11.2.2. Vendor Memory Model 11.2.3. Transcript Window Messages
11.3. Timing Issue Characteristics x
11.3.1. Evaluating FPGA Timing Issues 11.3.2. Evaluating External Memory Interface Timing Issues
1. About the External Memory Interfaces Agilex™ 5 FPGA IP
2. Agilex™ 5 FPGA EMIF IP – Introduction
3. Agilex™ 5 FPGA EMIF IP – Product Architecture
4. Agilex™ 5 FPGA EMIF IP – End-User Signals
5. Agilex™ 5 FPGA EMIF IP – Simulating Memory IP
6. Intel® Agilex™ 5 FPGA EMIF IP - DDR4 Support
7. Intel® Agilex™ 5 FPGA EMIF IP - LPDDR4 Support
8. Intel® Agilex™ 5 FPGA EMIF IP - LPDDR5 Support
9. Agilex™ 5 FPGA EMIF IP – Timing Closure
10. Agilex™ 5 FPGA EMIF IP – Controller Optimization
11. Agilex™ 5 FPGA EMIF IP – Debugging
12. Document Revision History for External Memory Interfaces (EMIF) IP User Guide

8.3.2. LPDDR5 General Design Considerations

General DDR Signal Routing Guideline on PCB

Intel recommends to route all data signals within a specific group on the same layer.

The figure below illustrates a routing example for a type-III PCB board for a DDR4, LPDDR4, or LPDDR5 design. Data Group signals such as DQ, DM and DQS signals should be routed on shallow layers as stripline with the least Z-height via transition to avoid vertical crosstalk to achieve high performance.

For example, the recommended routing layers for data group on a 20-layers board and using PTH via will be on the top half of the PCB such as L3, L5 and L7. Other signals such as CA, CTRL and clock signals can be routed with longer Z-height via transition on the bottom half of the PCB such as L14, L16 and L18.

Minimal stub effect or back drill is recommended, but not required, to avoid high reflection for maximum data rate performance. Long via stubs will affect the ISI of channel but the impact of ISI is less than impact of crosstalk for the max data rate performance.

Figure 49. Case A Routing is Suggested for Data Group Signals Over Case B

To minimize crosstalk horizontally between signals on the same layer, PCB designers must maintain adequate signal trace-to-trace (edge to edge) space, with a minimum spacing of 3xH separation distance, where H is the dielectric thickness to the closest reference plane as illustrated in the figure below.

Figure 50. Minimum Trace-to-Trace Separation Distance

DDR FPGA Break Out Routing

Agilex™ 5 devices come with various pitch sizes for different FPGA pins. The GPIO pin pitch is very small, the device BGA pad stack is also very small, therefore, it is highly recommended to use a dog bone configuration for inner GPIO pins fanout along with stripline routing; however, for the GPIO pins on the edge of device, it is recommended to use microstrip routing. Both microstrip and stripline routing guidelines are presented in this document for all supported EMIF interfaces and topologies.

DDR Differential Signals Routing

DQS and CLK signals in the DDR interface are differential signals and must be routed on PCB as differential signals unless there is a limitation for PCB routing such as having a very small pitch at DRAM area.

Intel recommends a symmetrical fan-out routing at the FPGA pin field. Non-symmetrical routing for differential signals will cause shifting on common-mode voltage and contributes to reduced timing margins at the receiver. The following figures show the recommended differential routing at the FPGA pin field for DQS/CLK signals.

The figure below shows the symmetrical routing of differential signals (DQS/CLK) at FPGA pin field along with length/skew matching between P/N lanes right after FPGA device edge.

Figure 51. Symmetrical Routing of Differential Signals (DQS/CLK) at FPGA Pin Field

The figure below shows the single-ended routing for differential signals (DQS/CLK) at DRAM pin field if the pitch is very small along with skew matching right at edge of DRAM pin field.

Figure 52. Single-ended Routing for Differential Signals (DQS/CLK) at DRAM

Intel recommends to implement length/skew matching for differential signals (if there is) right after FPGA device to avoid additional shifting on differential signals common mode voltage.

In case of having limitation for implementing symmetrical routing at DRAM pin field for differential signals due to very small pitch, Intel recommends to route the differential signals as single-ended signals within the DRAM pin field, ensuring to keep the same impedance while changing from differential to single-ended configuration. Designers must also keep the same length of routing for each P and N single-ended lane within the DRAM pin field. The skew matching between P/N lanes must be applied before reaching the DRAM pin field.

Ground Plane and Return Path

A continuous and solid ground reference plane is crucial for data lines to ensure good signal integrity performance. Low impedance ground return path from the FPGA to DRAM devices should be provisioned. In addition, it is desirable to keep ground stitching vias within 80 mils from signal transition for better return path on signal via and better signal integrity performance.

DRAM Break Out in Layout Guideline

For discrete DRAM components on PCB, you can either use the dog-bone or via in pad at DRAM for the signal transition from inner layer to DRAM. If dog-bone via transition is used, it is recommended to separate them with larger pitch to avoid crosstalk between signal vias.

Figure 53. Data Signal Group Routing on PCB for Memory Down Configuration
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