External Memory Interfaces Agilex™ 7 M-Series FPGA IP User Guide

Download PDF
ID 772538
Date 11/18/2024
Public
Document Table of Contents
Document Table of Contents x
1. About the External Memory Interfaces Agilex™ 7 M-Series FPGA IP 2. Agilex™ 7 M-Series FPGA EMIF IP – Introduction 3. Agilex™ 7 M-Series FPGA EMIF IP – Product Architecture 4. Agilex™ 7 M-Series FPGA EMIF IP – End-User Signals 5. Agilex™ 7 M-Series FPGA EMIF IP – Simulating Memory IP 6. Agilex™ 7 M-Series FPGA EMIF IP – DDR4 Support 7. Agilex™ 7 M-Series FPGA EMIF IP – DDR5 Support 8. Agilex™ 7 M-Series FPGA EMIF IP – LPDDR5 Support 9. Agilex™ 7 M-Series FPGA EMIF IP – Timing Closure 10. Agilex™ 7 M-Series FPGA EMIF IP – Controller Optimization 11. Agilex™ 7 M-Series FPGA EMIF IP – Debugging 12. Agilex™ 7 FPGA EMIF IP - Mailbox Support 13. Document Revision History for External Memory Interfaces Agilex™ 7 M-Series FPGA IP User Guide
1. About the External Memory Interfaces Agilex™ 7 M-Series FPGA IP x
1.1. Release Information
2. Agilex™ 7 M-Series FPGA EMIF IP – Introduction x
2.1. Agilex™ 7 M-Series EMIF IP Protocol and Feature Support 2.2. Agilex™ 7 M-Series EMIF IP Design Flow 2.3. Agilex™ 7 M-Series EMIF IP Design Checklist
3. Agilex™ 7 M-Series FPGA EMIF IP – Product Architecture x
3.1. Agilex™ 7 M-Series EMIF Architecture: Introduction 3.2. Agilex™ 7 M-Series EMIF Sequencer 3.3. Agilex™ 7 M-Series EMIF Controller 3.4. Agilex™ 7 M-Series EMIF IP for Hard Processor Subsystem (HPS)
3.1. Agilex™ 7 M-Series EMIF Architecture: Introduction x
3.1.1. Agilex™ 7 M-Series EMIF Architecture: I/O Subsystem 3.1.2. Agilex™ 7 M-Series EMIF Architecture: I/O SSM 3.1.3. Agilex™ 7 M-Series EMIF Architecture: I/O Bank 3.1.4. Agilex™ 7 M-Series EMIF Architecture: I/O Lane 3.1.5. Agilex™ 7 M-Series EMIF Architecture: Input DQS Clock Tree 3.1.6. Agilex™ 7 M-Series EMIF Architecture: PHY Clock Tree 3.1.7. Agilex™ 7 M-Series EMIF Architecture: PLL Reference Clock Networks 3.1.8. Agilex™ 7 M-Series EMIF Architecture: Clock Phase Alignment 3.1.9. User Clock in Different Core Access Modes
3.1.3. Agilex™ 7 M-Series EMIF Architecture: I/O Bank x
3.1.3.1. Lockstep Configuration 3.1.3.2. DDR4 Pin Placement 3.1.3.3. DDR5 Pin Placement 3.1.3.4. LPDDR5 Pin Placement 3.1.3.5. I/O Sub-Bank Usage
3.3. Agilex™ 7 M-Series EMIF Controller x
3.3.1. Hard Memory Controller
3.3.1. Hard Memory Controller x
3.3.1.1. Hard Memory Controller Features
4. Agilex™ 7 M-Series FPGA EMIF IP – End-User Signals x
4.1. IP Interfaces for External Memory Interfaces (EMIF) IP - DDR4 Component 4.2. IP Interfaces for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.3. IP Interfaces for External Memory Interfaces (EMIF) IP - DDR5 Component 4.4. IP Interfaces for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.5. IP Interfaces for External Memory Interfaces (EMIF) IP - LPDDR5
4.1. IP Interfaces for External Memory Interfaces (EMIF) IP - DDR4 Component x
4.1.1. s0_axi4_clock_in for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.2. s0_axi4_ctrl_ready for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.3. core_init_n for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.4. s0_axi4 for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.5. s0_axi4lite_clock for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.6. s0_axi4lite_reset_n for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.7. s0_axi4lite for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.8. mem_0 for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.9. mem_ck_0 for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.10. mem_reset_n for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.11. oct_0 for External Memory Interfaces (EMIF) IP - DDR4 Component 4.1.12. ref_clk for External Memory Interfaces (EMIF) IP - DDR4 Component
4.2. IP Interfaces for External Memory Interfaces (EMIF) IP - DDR4 DIMM x
4.2.1. s0_axi4_clock_out for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.2. s0_axi4_ctrl_ready for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.3. core_init_n for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.4. s0_axi4 for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.5. s0_axi4lite_clock for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.6. s0_axi4lite_reset_n for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.7. s0_axi4lite for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.8. mem_0 for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.9. mem_ck_0 for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.10. mem_reset_n for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.11. oct_0 for External Memory Interfaces (EMIF) IP - DDR4 DIMM 4.2.12. ref_clk for External Memory Interfaces (EMIF) IP - DDR4 DIMM
4.3. IP Interfaces for External Memory Interfaces (EMIF) IP - DDR5 Component x
4.3.1. s0_axi4_clock_in for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.2. s0_axi4_ctrl_ready for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.3. core_init_n for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.4. s0_axi4 for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.5. s0_axi4lite_clock for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.6. s0_axi4lite_reset_n for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.7. s0_axi4lite for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.8. mem_0 for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.9. mem_ck_0 for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.10. mem_reset_n_0 for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.11. oct_0 for External Memory Interfaces (EMIF) IP - DDR5 Component 4.3.12. ref_clk for External Memory Interfaces (EMIF) IP - DDR5 Component
4.4. IP Interfaces for External Memory Interfaces (EMIF) IP - DDR5 DIMM x
4.4.1. s0_axi4_ctrl_ready for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.2. s1_axi4_ctrl_ready for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.3. s0_axi4_clock_in for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.4. core_init_n for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.5. s0_axi4 for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.6. s1_axi4 for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.7. s0_axi4lite_clock for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.8. s0_axi4lite_reset_n for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.9. s0_axi4lite for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.10. s1_axi4lite_clock for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.11. s1_axi4lite_reset_n for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.12. s1_axi4lite for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.13. mem_0 for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.14. mem_1 for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.15. mem_reset_n for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.16. mem_ck_0 for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.17. mem_ck_1 for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.18. mem_i3c for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.19. oct_0 for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.20. oct_1 for External Memory Interfaces (EMIF) IP - DDR5 DIMM 4.4.21. ref_clk for External Memory Interfaces (EMIF) IP - DDR5 DIMM
4.5. IP Interfaces for External Memory Interfaces (EMIF) IP - LPDDR5 x
4.5.1. s0_axi4_clock_in for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.2. core_init_n for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.3. s0_axi4_ctrl_ready for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.4. s0_axi4 for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.5. s1_axi4 for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.6. s0_axi4lite_clock for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.7. s0_axi4lite_reset_n for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.8. s0_axi4lite for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.9. mem_0 for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.10. mem_ck_0 for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.11. mem_1 for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.12. mem_ck_1 for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.13. mem_reset_n for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.14. oct_0 for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.15. oct_1 for External Memory Interfaces (EMIF) IP - LPDDR5 4.5.16. ref_clk for External Memory Interfaces (EMIF) IP - LPDDR5
5. Agilex™ 7 M-Series 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. Agilex™ 7 M-Series FPGA EMIF IP – DDR4 Support x
6.1. External Memory Interfaces (EMIF) IP - DDR4 Component Parameter Descriptions 6.2. External Memory Interfaces (EMIF) IP - DDR4 DIMM Parameter Descriptions 6.3. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning 6.4. DDR4 Board Design Guidelines
6.3. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning x
6.3.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins 6.3.2. Agilex™ 7 M-Series FPGA EMIF IP Resources 6.3.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP 6.3.4. Pin Placements for Agilex™ 7 M-Series FPGA DDR4 EMIF IP
6.3.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins x
6.3.1.1. Estimating Pin Requirements 6.3.1.2. DIMM Options 6.3.1.3. Maximum Number of Interfaces
6.3.2. Agilex™ 7 M-Series FPGA EMIF IP Resources x
6.3.2.1. OCT 6.3.2.2. PLL
6.3.4. Pin Placements for Agilex™ 7 M-Series FPGA DDR4 EMIF IP x
6.3.4.1. Address and Command Pin Placement for DDR4 6.3.4.2. DDR4 Data Width Mapping 6.3.4.3. General Guidelines - DDR4 6.3.4.4. x4 DIMM Implementation 6.3.4.5. Specific Pin Connection Requirements 6.3.4.6. Command and Address Signals 6.3.4.7. Clock Signals 6.3.4.8. Data, Data Strobes, DM/DBI, and Optional ECC Signals
6.4. DDR4 Board Design Guidelines x
6.4.1. Terminations for DDR4 with Agilex™ 7 M-Series Devices 6.4.2. General Layout Routing Guidelines 6.4.3. Reference Stackup 6.4.4. Agilex™ 7 M-Series EMIF-Specific Routing Guidelines for Various DDR4 Topologies 6.4.5. DDR4 Routing Guidelines: Discrete (Component) Topologies
6.4.1. Terminations for DDR4 with Agilex™ 7 M-Series Devices x
6.4.1.1. Dynamic On-Chip Termination (OCT) 6.4.1.2. Dynamic On-Die Termination (ODT) in DDR4 6.4.1.3. Choosing Terminations on Agilex™ 7 M-Series FPGA Devices 6.4.1.4. On-Chip Termination Recommendations for Agilex™ 7 M-Series FPGA Devices
6.4.4. Agilex™ 7 M-Series EMIF-Specific Routing Guidelines for Various DDR4 Topologies x
6.4.4.1. One DIMM per Channel (1DPC) for UDIMM, RDIMM, and SODIMM DDR4 Topologies 6.4.4.2. Skew Matching Guidelines for DIMM Configurations 6.4.4.3. Power Delivery Recommendations for the Memory / DIMM Side
6.4.5. DDR4 Routing Guidelines: Discrete (Component) Topologies x
6.4.5.1. Single Rank and Dual Rank x 8 Discrete (Component) Topology 6.4.5.2. Single Rank x16 and Dual Rank x16 Discrete (Component) Topology 6.4.5.3. ADDR/CMD Reference Voltage/RESET Signal Routing Guidelines for Single Rank x 8 and Single Rank x 16 Discrete (Component) Topologies 6.4.5.4. Skew Matching Guidelines for DDR4 Discrete Configurations 6.4.5.5. Power Delivery Recommendations for DDR4 Discrete Configurations 6.4.5.6. Agilex™ 7 M-Series EMIF Pin Swapping Guidelines
6.4.5.6. Agilex™ 7 M-Series EMIF Pin Swapping Guidelines x
6.4.5.6.1. DDR4 Byte Lane Swapping 6.4.5.6.2. DDR4 Address and Command and CLK Lane 6.4.5.6.3. DDR4 Interface x8 Data Lane 6.4.5.6.4. DDR4 Interface x4 Data Lane 6.4.5.6.5. Pin Swizzling
7. Agilex™ 7 M-Series FPGA EMIF IP – DDR5 Support x
7.1. External Memory Interfaces (EMIF) IP - DDR5 Component Parameter Descriptions 7.2. External Memory Interfaces (EMIF) IP - DDR5 DIMM Parameter Descriptions 7.3. PHY DFE Tap Bias Values for DDR5 7.4. MEM DFE Tap Bias Values for DDR5 7.5. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning 7.6. DDR5 Board Design Guidelines
7.5. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning x
7.5.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins 7.5.2. Agilex™ 7 M-Series FPGA EMIF IP Resources 7.5.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP 7.5.4. Pin Placements for Agilex™ 7 M-Series FPGA DDR5 EMIF IP 7.5.5. Agilex™ 7 M-Series EMIF Pin Swapping Guidelines
7.5.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins x
7.5.1.1. Estimating Pin Requirements 7.5.1.2. DIMM Options 7.5.1.3. Maximum Number of Interfaces
7.5.2. Agilex™ 7 M-Series FPGA EMIF IP Resources x
7.5.2.1. OCT 7.5.2.2. PLL
7.5.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP x
7.5.3.1. General Guidelines - DDR5 7.5.3.2. x4 DIMM Implementation 7.5.3.3. Specific Pin Connection Requirements 7.5.3.4. Command and Address Signals 7.5.3.5. Clock Signals 7.5.3.6. Data, Data Strobes, DM, and Optional ECC Signals
7.5.4. Pin Placements for Agilex™ 7 M-Series FPGA DDR5 EMIF IP x
7.5.4.1. Address and Command Pin Placement for DDR5 7.5.4.2. DDR5 Data Width Mapping
7.5.5. Agilex™ 7 M-Series EMIF Pin Swapping Guidelines x
7.5.5.1. DDR5 Byte Lane Swapping 7.5.5.2. DDR5 Address and Command and CLK Lane 7.5.5.3. DDR5 Interface x8 Data Lane 7.5.5.4. DDR5 Interface x4 Data Lane 7.5.5.5. Pin Swizzling
7.6. DDR5 Board Design Guidelines x
7.6.1. PCB Stack-up and Design Considerations 7.6.2. General Design Considerations 7.6.3. DDR Differential Signals Routing 7.6.4. Ground Plane and Return Path 7.6.5. RDIMM, UDIMM, and SODIMM Break-in Layout Guidelines 7.6.6. DRAM Break-in Layout Guidelines 7.6.7. General Notes for EMIF Routing Guidelines Tables 7.6.8. DDR5 PCB Layout Guidelines 7.6.9. DDR5 RDIMM Power Management IC 7.6.10. DDR5 Simulation Strategy
7.6.8. DDR5 PCB Layout Guidelines x
7.6.8.1. DDR5 Discrete Component/Memory Down Topology: Single Rank x8 or x16, Dual Rank x8 or x16 7.6.8.2. Routing Guidelines for DDR5 Memory Down: Single Rank or Dual Rank (x8 bit or x16 bit) Configurations 7.6.8.3. Routing Guidelines for DDR5 RDIMM, UDIMM, and SODIMM Configurations 7.6.8.4. Example of a DDR5 layout on an Altera FPGA Platform Board
8. Agilex™ 7 M-Series FPGA EMIF IP – LPDDR5 Support x
8.1. External Memory Interfaces (EMIF) IP - LPDDR5 Parameter Descriptions 8.2. PHY DFE Tap Bias Values for LPDDR5 8.3. MEM DFE Tap Bias Values for LPDDR5 8.4. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning 8.5. LPDDR5 Board Design Guidelines
8.4. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning x
8.4.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins 8.4.2. Agilex™ 7 M-Series FPGA EMIF IP Resources 8.4.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP 8.4.4. Pin Placements for Agilex™ 7 M-Series FPGA LPDDR5 EMIF IP
8.4.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins x
8.4.1.1. Estimating Pin Requirements 8.4.1.2. LPDDR5 Component Options 8.4.1.3. Maximum Number of Interfaces
8.4.2. Agilex™ 7 M-Series FPGA EMIF IP Resources x
8.4.2.1. OCT 8.4.2.2. PLL
8.4.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP x
8.4.3.1. General Guidelines - LPDDR5 8.4.3.2. Specific Pin Connection Requirements 8.4.3.3. Command and Address Signals 8.4.3.4. Clock Signals
8.4.4. Pin Placements for Agilex™ 7 M-Series FPGA LPDDR5 EMIF IP x
8.4.4.1. Address and Command Pin Placement for LPDDR5 8.4.4.2. LPDDR5 Data Width Mapping 8.4.4.3. LPDDR5 Byte Lane Swapping
8.5. LPDDR5 Board Design Guidelines x
8.5.1. PCB Stack-up and Design Considerations 8.5.2. General Design Considerations 8.5.3. DDR Differential Signals Routing 8.5.4. Ground Plane and Return Path 8.5.5. DRAM Break-in Layout Guidelines 8.5.6. General Notes for EMIF Routing Guidelines Tables 8.5.7. LPDDR5 PCB Layout Guidelines 8.5.8. LPDDR5 Simulation Strategy
8.5.7. LPDDR5 PCB Layout Guidelines x
8.5.7.1. LPDDR5 Discrete Component/Memory Down Topology, Single Rank or Dual Rank 8.5.7.2. Routing Guidelines for LPDDR5 Memory Down Topology 8.5.7.3. Example of an LPDDR5 Layout on an Altera® FPGA Platform Board
9. Agilex™ 7 M-Series 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™ 7 M-Series 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 10.4.3. AXI to Memory Mapping
11. Agilex™ 7 M-Series 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. Debugging with the External Memory Interface Debug Toolkit 11.6. Generating Traffic with the Test Engine IP 11.7. Guidelines for Developing HDL for Traffic Generator 11.8. Guidelines for Traffic Generator Status Check
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. Altera 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
11.5. Debugging with the External Memory Interface Debug Toolkit x
11.5.1. Prerequisites for Using the EMIF Debug Toolkit 11.5.2. Configuring Your Design to Use the EMIF Debug Toolkit 11.5.3. Launching the EMIF Debug Toolkit 11.5.4. Using the EMIF Debug Toolkit
11.5.4. Using the EMIF Debug Toolkit x
11.5.4.1. Rerunning Calibration 11.5.4.2. Rerunning the Test Engine 11.5.4.3. Saving Debug Print 11.5.4.4. Calibration Reports 11.5.4.5. Driver Margining Tab 11.5.4.6. Pin Delay Settings Tab
11.8. Guidelines for Traffic Generator Status Check x
11.8.1. Status Check Using the Signal Tap Logic Analyzer 11.8.2. Exporting the Status Interface to the Top-Level Design
12. Agilex™ 7 FPGA EMIF IP - Mailbox Support x
12.1. Agilex™ 7 Mailbox Structure and Register Definitions 12.2. Sending a Mailbox Command
12.1. Agilex™ 7 Mailbox Structure and Register Definitions x
12.1.1. Mailbox Supported Commands 12.1.2. Mailbox Command Definitions 12.1.3. ECC Syndrome Codes
12.2. Sending a Mailbox Command x
12.2.1. Example 1: Reading IP_TYPE and IP_INSTANCE_ID of All the Interfaces in the IO96B Using Mailbox 12.2.2. Example 2: Reading the Memory Clock Frequency for an Interface 12.2.3. Example 3: Sending Recalibration Request and Reading Calibration Status Using the Mailbox
1. About the External Memory Interfaces Agilex™ 7 M-Series FPGA IP
2. Agilex™ 7 M-Series FPGA EMIF IP – Introduction
3. Agilex™ 7 M-Series FPGA EMIF IP – Product Architecture
4. Agilex™ 7 M-Series FPGA EMIF IP – End-User Signals
5. Agilex™ 7 M-Series FPGA EMIF IP – Simulating Memory IP
6. Agilex™ 7 M-Series FPGA EMIF IP – DDR4 Support
7. Agilex™ 7 M-Series FPGA EMIF IP – DDR5 Support
8. Agilex™ 7 M-Series FPGA EMIF IP – LPDDR5 Support
9. Agilex™ 7 M-Series FPGA EMIF IP – Timing Closure
10. Agilex™ 7 M-Series FPGA EMIF IP – Controller Optimization
11. Agilex™ 7 M-Series FPGA EMIF IP – Debugging
12. Agilex™ 7 FPGA EMIF IP - Mailbox Support
13. Document Revision History for External Memory Interfaces Agilex™ 7 M-Series FPGA IP User Guide

6.3.4.8. Data, Data Strobes, DM/DBI, and Optional ECC Signals

DDR4 SDRAM devices use bidirectional differential data strobes. Differential DQS operation enables improved system timing due to reduced crosstalk and less simultaneous switching noise on the strobe output drivers. The DQ pins are also bidirectional.

DQ pins in DDR4 SDRAM interfaces can operate in either ×4 or ×8 mode DQS groups, depending on your chosen memory device or DIMM, regardless of interface width. The ×4 and ×8 configurations use one pair of bidirectional data strobe signals, DQS and DQSn, to capture input data. However, two pairs of data strobes, UDQS and UDQS# (upper byte) and LDQS and LDQS# (lower byte), are required by ×16 configurations. A group of DQ pins must remain associated with its respective DQS and DQSn pins.

The DQ signals are edge-aligned with the DQS signal during a read from the memory and are center-aligned with the DQS signal during a write to the memory. The memory controller shifts the DQ signals by –90 degrees during a write operation to center align the DQ and DQS signals. The PHY IP delays the DQS signal during a read, so that the DQ and DQS signals are center aligned at the capture register. Altera devices use a phase-locked loop (PLL) to center-align the DQS signal with respect to the DQ signals during writes and use dedicated DQS phase-shift circuitry to shift the incoming DQS signal during reads. The following figure shows an example where the DQS signal is shifted by 90 degrees for a read from the SDRAM.

Figure 13. Edge-aligned DQ and DQS Relationship During a SDRAM Read in Burst-of-Four Mode


The following figure shows an example of the relationship between the data and data strobe during a burst-of-four write.

Figure 14. DQ and DQS Relationship During a SDRAM Write in Burst-of-Four Mode


The memory device's setup (tDS) and hold times (tDH) for the DQ and DM pins during writes are relative to the edges of DQS write signals and not the CK or CK# clock. Setup and hold requirements are not necessarily balanced.

The DQS signal is generated on the positive edge of the system clock to meet the tDQSS requirement. DQ and DM signals use a clock shifted –90 degrees from the system clock, so that the DQS edges are centered on the DQ or DM signals when they arrive at the SDRAM. The DQS, DQ, and DM board trace lengths need to be tightly matched (within 20 ps).

The SDRAM uses the DM pins during a write operation. Driving the DM pins low shows that the write is valid. The memory masks the DQ signals if the DM pins are driven high. To generate the DM signal, Altera recommends that you use the spare DQ pin within the same DQS group as the respective data, to minimize skew.

The DM signal's timing requirements at the SDRAM input are identical to those for DQ data. The DDR registers, clocked by the –90 degree shifted clock, create the DM signals.

DDR4 supports DM similarly to other SDRAM, except that in DDR4 DM is active LOW and bidirectional, because it supports Data Bus Inversion (DBI) through the same pin. DM is multiplexed with DBI by a Mode Register setting whereby only one function can be enabled at a time. DBI is an input/output identifying whether to store/output the true or inverted data. When enabled, if DBI is LOW, during a write operation the data is inverted and stored inside the DDR4 SDRAM; during a read operation, the data is inverted and output. The data is not inverted if DBI is HIGH. For Agilex™ 7 interfaces, the DM/DBI pins do not need to be paired with a DQ pin.

Some SDRAM modules support error correction coding (ECC) to allow the controller to detect and automatically correct error in data transmission. The 72-bit SDRAM modules contain eight extra data pins in addition to 64 data pins. The eight extra ECC pins should be connected to a single DQS or DQ group on the FPGA.

Level Two Title