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1. About the External Memory Interfaces Intel Agilex® 7 M-Series FPGA IP
2. Intel Agilex® 7 M-Series FPGA EMIF IP – Introduction
3. Intel Agilex® 7 M-Series FPGA EMIF IP – Product Architecture
4. Intel Agilex® 7 M-Series FPGA EMIF IP – End-User Signals
5. Intel Agilex® 7 M-Series FPGA EMIF IP – Simulating Memory IP
6. Intel Agilex 7 M-Series FPGA EMIF IP – DDR4 Support
7. Intel Agilex® 7 M-Series FPGA EMIF IP – DDR5 Support
8. Intel Agilex 7 M-Series FPGA EMIF IP – LPDDR5 Support
9. Intel Agilex® 7 M-Series FPGA EMIF IP – Timing Closure
10. Intel Agilex® 7 M-Series FPGA EMIF IP – Controller Optimization
11. Intel Agilex® 7 M-Series FPGA EMIF IP – Debugging
12. Document Revision History for External Memory Interfaces Intel Agilex® 7 M-Series FPGA IP User Guide
3.1.1. Intel Agilex® 7 M-Series EMIF Architecture: I/O Subsystem
3.1.2. Intel Agilex® 7 M-Series EMIF Architecture: I/O SSM
3.1.3. Intel Agilex® 7 M-Series EMIF Architecture: I/O Bank
3.1.4. Intel Agilex® 7 M-Series EMIF Architecture: I/O Lane
3.1.5. Intel Agilex® 7 M-Series EMIF Architecture: Input DQS Clock Tree
3.1.6. Intel Agilex® 7 M-Series EMIF Architecture: PHY Clock Tree
3.1.7. Intel Agilex® 7 M-Series EMIF Architecture: PLL Reference Clock Networks
3.1.8. Intel Agilex® 7 M-Series EMIF Architecture: Clock Phase Alignment
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
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
6.3.5.1. 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. Intel Agilex® 7 M-Series EMIF Pin Swapping Guidelines
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6.3.5.4. Skew Matching Guidelines for DDR4 Discrete Configurations
This topic describes skew matching guidelines for single rank x 8 and single rank x 16 topologies.
Observe the following rules when skew matching DDR4 discrete configurations:
- Perform skew matching in time (picoseconds) rather than in actual trace length, to better account for via delays when signals are routed on different layers.
- Include both package per-pin skew and PCB delay when performing skew matching.
- Skew (length) matching for the alert signal is not required.
The following table provides skew matching guidelines for DDR4 down-memory topologies.
DDR4 Device-down Length Matching Rules | Length Matching in Time (ps) |
---|---|
Skew matching between DQS and CLK | -85ps < CLK - DQS < 935ps |
Skew matching between DQ and DQS within byte | -3.5ps < DQ - DQS < 3.5ps |
Skew matching between DQS and DQS# | < 1ps |
Skew matching between CLK and CLK# | < 1ps |
Skew matching between CMD/ADDR/CTRL and Clock | -20ps < CLK - CMD/ADDR/CTRL < 20ps |
Skew matching among CMD/ADDR/CTRL within each channel | < 20ps |
Include package length in skew matching for FPGA device with no migration | Required |
Include package length in skew matching for FPGA device with migration when all package net length are available | It is recommended to use the final migrated package net length |
Include package length in skew matching for FPGA device with migration when all package net length are not available | Not recommended |