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

Download PDF
ID 772538
Date 7/08/2024
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. 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
3.2. Agilex™ 7 M-Series EMIF Sequencer x
3.2.1. Agilex™ 7 M-Series Mailbox Structure and Register Definitions
3.2.1. Agilex™ 7 M-Series Mailbox Structure and Register Definitions x
3.2.1.1. Mailbox Supported Commands 3.2.1.2. Mailbox Command Definitions
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. Agilex™ 7 M-Series EMIF IP Interfaces for DDR4 4.2. Agilex™ 7 M-Series EMIF IP Interfaces for DDR5 4.3. Agilex™ 7 M-Series EMIF IP Interfaces for LPDDR5 4.4. Agilex™ 7 M-Series EMIF IP Interfaces for Calibration Component
4.1. Agilex™ 7 M-Series EMIF IP Interfaces for DDR4 x
4.1.1. ref_clk for External Memory Interfaces (EMIF) IP 4.1.2. core_init_n for External Memory Interfaces (EMIF) IP 4.1.3. usr_async_clk for External Memory Interfaces (EMIF) IP 4.1.4. usr_clk for External Memory Interfaces (EMIF) IP 4.1.5. usr_rst_n for External Memory Interfaces (EMIF) IP 4.1.6. s0_axi4 for External Memory Interfaces (EMIF) IP 4.1.7. mem for External Memory Interfaces (EMIF) IP 4.1.8. oct for External Memory Interfaces (EMIF) IP
4.2. Agilex™ 7 M-Series EMIF IP Interfaces for DDR5 x
4.2.1. ref_clk for External Memory Interfaces (EMIF) IP 4.2.2. core_init_n for External Memory Interfaces (EMIF) IP 4.2.3. usr_async_clk for External Memory Interfaces (EMIF) IP 4.2.4. usr_clk for External Memory Interfaces (EMIF) IP 4.2.5. usr_rst_n for External Memory Interfaces (EMIF) IP 4.2.6. s0_axi4 for External Memory Interfaces (EMIF) IP 4.2.7. mem for External Memory Interfaces (EMIF) IP 4.2.8. i3c for External Memory Interfaces (EMIF) IP 4.2.9. mem_lbd for External Memory Interfaces (EMIF) IP 4.2.10. mem_lbs for External Memory Interfaces (EMIF) IP 4.2.11. oct for External Memory Interfaces (EMIF) IP
4.3. Agilex™ 7 M-Series EMIF IP Interfaces for LPDDR5 x
4.3.1. ref_clk for External Memory Interfaces (EMIF) IP 4.3.2. core_init_n for External Memory Interfaces (EMIF) IP 4.3.3. usr_async_clk for External Memory Interfaces (EMIF) IP 4.3.4. usr_clk for External Memory Interfaces (EMIF) IP 4.3.5. usr_rst_n for External Memory Interfaces (EMIF) IP 4.3.6. s0_axi4 for External Memory Interfaces (EMIF) IP 4.3.7. mem for External Memory Interfaces (EMIF) IP 4.3.8. oct for External Memory Interfaces (EMIF) IP
4.4. Agilex™ 7 M-Series EMIF IP Interfaces for Calibration Component x
4.4.1. s0_axi4lite_clk for External Memory Interface Calibration Component 4.4.2. s0_axi4lite_rst_n for External Memory Interface Calibration Component 4.4.3. s0_axil for External Memory Interface Calibration Component
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. Agilex™ 7 M-Series FPGA EMIF IP Parameters for DDR4 6.2. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning 6.3. DDR4 Board Design Guidelines
6.1. Agilex™ 7 M-Series FPGA EMIF IP Parameters for DDR4 x
6.1.1. Agilex™ 7 M-Series FPGA EMIF IP Parameter Descriptions for DDR4 6.1.2. Agilex™ 7 M-Series FPGA EMIF Memory Device IP Parameter Descriptions for DDR4 6.1.3. Agilex™ 7 M-Series FPGA EMIF Calibration IP Parameter Descriptions
6.2. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning x
6.2.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins 6.2.2. Agilex™ 7 M-Series FPGA EMIF IP Resources 6.2.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP 6.2.4. Pin Placements for Agilex™ 7 M-Series FPGA DDR4 EMIF IP
6.2.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins x
6.2.1.1. Estimating Pin Requirements 6.2.1.2. DIMM Options 6.2.1.3. Maximum Number of Interfaces
6.2.2. Agilex™ 7 M-Series FPGA EMIF IP Resources x
6.2.2.1. OCT 6.2.2.2. PLL
6.2.4. Pin Placements for Agilex™ 7 M-Series FPGA DDR4 EMIF IP x
6.2.4.1. Address and Command Pin Placement for DDR4 6.2.4.2. DDR4 Data Width Mapping 6.2.4.3. General Guidelines - DDR4 6.2.4.4. x4 DIMM Implementation 6.2.4.5. Specific Pin Connection Requirements 6.2.4.6. Command and Address Signals 6.2.4.7. Clock Signals 6.2.4.8. Data, Data Strobes, DM/DBI, and Optional ECC Signals
6.3. DDR4 Board Design Guidelines x
6.3.1. Terminations for DDR4 with Agilex™ 7 M-Series Devices 6.3.2. General Layout Routing Guidelines 6.3.3. Reference Stackup 6.3.4. Agilex™ 7 M-Series EMIF-Specific Routing Guidelines for Various DDR4 Topologies 6.3.5. DDR4 Routing Guidelines: Discrete (Component) Topologies
6.3.1. Terminations for DDR4 with Agilex™ 7 M-Series Devices x
6.3.1.1. Dynamic On-Chip Termination (OCT) 6.3.1.2. Dynamic On-Die Termination (ODT) in DDR4 6.3.1.3. Choosing Terminations on Agilex™ 7 M-Series FPGA Devices 6.3.1.4. On-Chip Termination Recommendations for Agilex™ 7 M-Series FPGA Devices
6.3.4. Agilex™ 7 M-Series EMIF-Specific Routing Guidelines for Various DDR4 Topologies x
6.3.4.1. One DIMM per Channel (1DPC) for UDIMM, RDIMM, and SODIMM DDR4 Topologies 6.3.4.2. Skew Matching Guidelines for DIMM Configurations 6.3.4.3. Power Delivery Recommendations for the Memory / DIMM Side
6.3.5. DDR4 Routing Guidelines: Discrete (Component) Topologies x
6.3.5.1. Single Rank x 8 Discrete (Component) Topology 6.3.5.2. Single Rank x 16 Discrete (Component) Topology 6.3.5.3. ADDR/CMD Reference Voltage/RESET Signal Routing Guidelines for Single Rank x 8 and Single Rank x 16 Discrete (Component) Topologies 6.3.5.4. Skew Matching Guidelines for DDR4 Discrete Configurations 6.3.5.5. Power Delivery Recommendations for DDR4 Discrete Configurations 6.3.5.6. Agilex™ 7 M-Series EMIF Pin Swapping Guidelines
6.3.5.6. Agilex™ 7 M-Series EMIF Pin Swapping Guidelines x
6.3.5.6.1. DDR4 Byte Lane Swapping 6.3.5.6.2. DDR4 Address and Command and CLK Lane 6.3.5.6.3. DDR4 Interface x8 Data Lane 6.3.5.6.4. DDR4 Interface x4 Data Lane 6.3.5.6.5. Pin Swizzling
7. Agilex™ 7 M-Series FPGA EMIF IP – DDR5 Support x
7.1. Agilex™ 7 M-Series FPGA EMIF IP Parameters for DDR5 7.2. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning 7.3. DDR5 Board Design Guidelines
7.1. Agilex™ 7 M-Series FPGA EMIF IP Parameters for DDR5 x
7.1.1. Agilex™ 7 M-Series FPGA EMIF IP Parameter Descriptions for DDR5 7.1.2. Agilex™ 7 M-Series FPGA EMIF Memory Device IP Parameter Descriptions for DDR5 7.1.3. Agilex™ 7 M-Series FPGA EMIF Calibration IP Parameter Descriptions
7.2. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning x
7.2.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins 7.2.2. Agilex™ 7 M-Series FPGA EMIF IP Resources 7.2.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP 7.2.4. Pin Placements for Agilex™ 7 M-Series FPGA DDR5 EMIF IP 7.2.5. Agilex™ 7 M-Series EMIF Pin Swapping Guidelines
7.2.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins x
7.2.1.1. Estimating Pin Requirements 7.2.1.2. DIMM Options 7.2.1.3. Maximum Number of Interfaces
7.2.2. Agilex™ 7 M-Series FPGA EMIF IP Resources x
7.2.2.1. OCT 7.2.2.2. PLL
7.2.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP x
7.2.3.1. General Guidelines - DDR5 7.2.3.2. x4 DIMM Implementation 7.2.3.3. Specific Pin Connection Requirements 7.2.3.4. Command and Address Signals 7.2.3.5. Clock Signals 7.2.3.6. Data, Data Strobes, DM, and Optional ECC Signals
7.2.4. Pin Placements for Agilex™ 7 M-Series FPGA DDR5 EMIF IP x
7.2.4.1. Address and Command Pin Placement for DDR5 7.2.4.2. DDR5 Data Width Mapping
7.2.5. Agilex™ 7 M-Series EMIF Pin Swapping Guidelines x
7.2.5.1. DDR5 Byte Lane Swapping 7.2.5.2. DDR5 Address and Command and CLK Lane 7.2.5.3. DDR5 Interface x8 Data Lane 7.2.5.4. DDR5 Interface x4 Data Lane 7.2.5.5. Pin Swizzling
7.3. DDR5 Board Design Guidelines x
7.3.1. PCB Stack-up and Design Considerations 7.3.2. General Design Considerations 7.3.3. DDR Differential Signals Routing 7.3.4. Ground Plane and Return Path 7.3.5. RDIMM, UDIMM, and SODIMM Break-in Layout Guidelines 7.3.6. DRAM Break-in Layout Guidelines 7.3.7. DDR5 PCB Layout Guidelines 7.3.8. DDR5 Simulation Strategy
7.3.7. DDR5 PCB Layout Guidelines x
7.3.7.1. DDR5 Discrete Component/Memory Down Topology: up to 40-Bit Interface (1 Rank x8 or x16, 2 Rank x8 or x16) 7.3.7.2. Routing Guidelines for DDR5 Memory Down: 1 Rank or 2 Rank (x8 bit or x16 bit) Configurations 7.3.7.3. Routing Guidelines for DDR5 RDIMM, UDIMM, and SODIMM Configurations 7.3.7.4. Example of a DDR5 layout on an Altera FPGA Platform Board
8. Agilex™ 7 M-Series FPGA EMIF IP – LPDDR5 Support x
8.1. Agilex™ 7 M-Series FPGA EMIF IP Parameters for LPDDR5 8.2. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning 8.3. LPDDR5 Board Design Guidelines
8.1. Agilex™ 7 M-Series FPGA EMIF IP Parameters for LPDDR5 x
8.1.1. Agilex™ 7 M-Series FPGA EMIF IP Parameter Descriptions for LPDDR5 8.1.2. Agilex™ 7 M-Series FPGA EMIF Memory Device IP Parameter Descriptions for LPDDR5 8.1.3. Agilex™ 7 M-Series FPGA EMIF Calibration IP Parameter Descriptions
8.2. Agilex™ 7 M-Series FPGA EMIF IP Pin and Resource Planning x
8.2.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins 8.2.2. Agilex™ 7 M-Series FPGA EMIF IP Resources 8.2.3. Pin Guidelines for Agilex™ 7 M-Series FPGA EMIF IP 8.2.4. Pin Placements for Agilex™ 7 M-Series FPGA LPDDR5 EMIF IP
8.2.1. Agilex™ 7 M-Series FPGA EMIF IP Interface Pins x
8.2.1.1. Estimating Pin Requirements 8.2.1.2. DIMM Options 8.2.1.3. Maximum Number of Interfaces
8.2.2. Agilex™ 7 M-Series FPGA EMIF IP Resources x
8.2.2.1. OCT 8.2.2.2. PLL
8.2.3. Pin Guidelines for Agilex™ 7 M-Series 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 Agilex™ 7 M-Series 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 Board Design Guidelines x
8.3.1. PCB Stack-up and Design Considerations 8.3.2. General Design Considerations 8.3.3. DDR Differential Signals Routing 8.3.4. Ground Plane and Return Path 8.3.5. DRAM Break-in Layout Guidelines 8.3.6. LPDDR5 PCB Layout Guidelines 8.3.7. LPDDR5 Simulation Strategy
8.3.6. LPDDR5 PCB Layout Guidelines x
8.3.6.1. LPDDR5 Discrete Component/Memory Down Topology (1 Rank or 2 Rank, up to 64 Bit Interface) 8.3.6.2. Supported LPDDR5 Topologies 8.3.6.3. 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
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. Document Revision History for External Memory Interfaces Agilex™ 7 M-Series FPGA IP User Guide

8.3.6.2. Supported LPDDR5 Topologies

The figures in this topic show various supported LPDDR5 topologies, based on the type of DRAM component, number of supported channels, and ranks.

Figure 64. Dual-Channel Single-Rank x16, Dual-Die DRAM Component

In the above figure, all signals from the controller to DRAM package are point-to-point connections.

Figure 65. Dual-Channel Dual-Rank x16, Using Quad-die DRAM Component

In the above figure, all signals from the controller to DRAM package are point-to-point connections.

Figure 66. Single-Channel Single-Rank x32, Using Dual-die DRAM Component

In the above figure, CK, WCK and CA/CS signals from the controller to DRAM are via T-Line connection; each WCK signal from the controller can be connected to both DRAM dies via T-Line, or can be connected to both WCK signals at each DRAM die via T-line.

Figure 67. Single-Channel Dual-Rank x32, Using a Quad-die DRAM component

In the above figure, CK, WCK and CA/CS signals from the controller to DRAM are via T-Line connection.

Figure 68. Dual-Channel Single Rank x16, Using a dual-die DRAM Component

In the above figure, all signals from the controller to DRAM package are point to point connections, except the CK signal which is connected via T-Line in power mode optimization.

Figure 69. Quad-Channel Single Rank x16, Using a Quad-Die DRAM Component

In the above figure, all signals from the controller to DRAM package are point-to-point connections

Figure 70. Quad-Channel Dual-Rank x16, Using an 8-die DRAM Component

In the above figure, all signals from the controller to DRAM package are point-to-point connections.

Figure 71. Dual-Channel-Single -Rank x32, Using a Quad-Die DRAM Component

In the above figure, CK, WCK and CA/CS signals are connected to both DRAM dies via T-Line connection.

The following table provides comprehensive routing guidelines (recommended trace impedance and length) for each LPDDR5 signal, based on a memory down topology. For example, the maximum length of the main trace routing can be derived from total trace length by subtracting the break-out and break-in trace segment lengths.

The signal trace width, and minimum spacing/gaps (in mils) from edge-to-edge of signal traces are based on the default stackup shown in the PCB Stack-up and Design Considerations topic; however, PCB designers can use the target impedance for any other stackups. The h value in the table represents the minimum substrate height from signal layer to reference layer.

Table 177.  Routing Guidelines for LPDDR5 Memory Down Topology

Reset signal routing design also follows the CMD/ADD/CTRL routing design. Maintain at least 5x h edge-to-edge spacing from the Reset signal to other signals on the same layer. There is no requirement to have skew matching between Reset signal and CLK signal.

Skew matching for the LPDDR5 interface consists of both package routing skew and PCB physical routing skew. You must maintain skew matching of CA and CTRL with respect to the clock signals to ensure signals at the receiver are correctly sampled. In addition, there are skew matching requirements for DQ and DQS within a byte group, DQS and CLK.

The following table provides a detailed skew matching guideline to facilitate PCB trace routing efforts. The length matching criteria in the table below represents a default PCB on an Altera platform board design. Skew matching criteria must be always followed in any other stackup.

Table 178.  Skew Matching Requirement for LPDDR5 Memory Down Topology

LPDDR5 eye margin is sensitive to crosstalk, especially when the signals are routed on deep layers in the stackup. The deep-layer vertical transition induces more vertical coupling between signals and hence more crosstalk.

Altera recommends keeping the via transition depth in Z-direction to less than 16mil (routed on shallow layers with backdrill) to achieve high performance on the LPDDR5 interface. The maximum data rate of LPDDR5 depends on the type of PCB and on the DDR memory down configuration as seen in the following table.

Table 179.  DQ Routing Summary for LPDDR5 Memory Down
Memory LPDDR5
Signal; Group DQ
Board Thickness (mil) 65mil or 120mil (Routing must be on upper layers, max via transition depth <=16mil) 65mil or 120mil (Routing must be on upper layers, max via transition depth <=16mil)
Maximum Z-transition height (mil) 16 16
PCB Stripline Trace Impedance (Ohms) 40 40
Memory Configuration Memory Down Memory Down
# of Rank 1 (x16 bit or x32 bit Double Die) 2 (x 16 or x 32 bit)
Maximum Length Total (Inch) 3.0 3.0
Notes Maximum package length in FPGA design is shorter than 34mm.
Level Two Title