Agilex™ 7 Embedded Memory User Guide

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ID 683241
Date 7/24/2025
Public
Document Table of Contents
Document Table of Contents x
1. Agilex™ 7 Embedded Memory Overview 2. Agilex™ 7 Embedded Memory Architecture and Features 3. Agilex™ 7 Embedded Memory Design Considerations 4. Agilex™ 7 Embedded Memory IP References 5. Agilex™ 7 Embedded Memory Debugging 6. Agilex™ 7 Embedded Memory User Guide Archives 7. Document Revision History for the Agilex™ 7 Embedded Memory User Guide
1. Agilex™ 7 Embedded Memory Overview x
1.1. Agilex™ 7 Embedded Memory Features
2. Agilex™ 7 Embedded Memory Architecture and Features x
2.1. Fabric Network-On-Chip (NoC) in Agilex™ 7 M-Series M20K Blocks 2.2. Byte Enable in Agilex™ 7 Embedded Memory Blocks 2.3. Address Clock Enable Support 2.4. Asynchronous Clear and Synchronous Clear 2.5. Memory Blocks Error Correction Code (ECC) Support 2.6. Agilex™ 7 Embedded Memory Clocking Modes 2.7. Agilex™ 7 Embedded Memory Configurations 2.8. Force-to-Zero 2.9. Coherent Read Memory 2.10. Freeze Logic 2.11. True Dual Port Dual Clock Emulator 2.12. Initial Value of Read and Write Address Registers 2.13. Timing/Power Optimization Feature in M20K Blocks 2.14. Agilex™ 7 Supported Embedded Memory IPs
2.2. Byte Enable in Agilex™ 7 Embedded Memory Blocks x
2.2.1. Byte Enable Controls 2.2.2. Data Byte Output 2.2.3. Byte Enable Behavior
2.5. Memory Blocks Error Correction Code (ECC) Support x
2.5.1. Error Correction Code Truth Table 2.5.2. Parity Bit 2.5.3. ECC Parity Flip 2.5.4. ECC Read-During-Write Behavior
2.6. Agilex™ 7 Embedded Memory Clocking Modes x
2.6.1. Single Clock Mode 2.6.2. Read/Write Clock Mode 2.6.3. Input/Output Clock Mode 2.6.4. Asynchronous/Synchronous Clears in Clocking Modes 2.6.5. Output Read Data in Simultaneous Read/Write 2.6.6. Independent Clock Enables in Clocking Modes
2.7. Agilex™ 7 Embedded Memory Configurations x
2.7.1. Mixed-Width Port Configurations
2.9. Coherent Read Memory x
2.9.1. Forwarding Logic
2.11. True Dual Port Dual Clock Emulator x
2.11.1. True Dual-Port Mixed Port Read During Write New Data Emulation
3. Agilex™ 7 Embedded Memory Design Considerations x
3.1. Consider the Memory Block Selection 3.2. Consider the Concurrent Read Behavior 3.3. Read-During-Write (RDW) 3.4. Consider Power-Up State and Memory Initialization 3.5. Reduce Power Consumption 3.6. Avoid Providing Non-Deterministic Input 3.7. Avoid Changing Clock Signals and Other Control Signals Simultaneously 3.8. Advanced Settings in Quartus® Prime Software for Memory 3.9. Consider the Memory Depth Setting 3.10. M20K Embedded Memory Block Input Clock Quality Requirement 3.11. Consider Registering the Memory Output
3.3. Read-During-Write (RDW) x
3.3.1. Customize Read-During-Write Behavior
3.3.1. Customize Read-During-Write Behavior x
3.3.1.1. Same-Port Read-During-Write Mode 3.3.1.2. Mixed-Port Read-During-Write Mode
4. Agilex™ 7 Embedded Memory IP References x
4.1. On-Chip Memory RAM and ROM IPs 4.2. eSRAM Agilex™ FPGA IP 4.3. FIFO IP 4.4. Shift Register (RAM-based) FPGA IP
4.1. On-Chip Memory RAM and ROM IPs x
4.1.1. Release Information for RAM and ROM IPs 4.1.2. RAM: 1-PORT FPGA IP Parameters 4.1.3. RAM: 2-PORT FPGA IP Parameters 4.1.4. RAM: 4-PORT FPGA IP Parameters 4.1.5. ROM: 1-PORT FPGA IP Parameters 4.1.6. ROM: 2-PORT FPGA IP Parameters 4.1.7. Changing Parameter Settings Manually 4.1.8. RAM and ROM Interface Signals
4.1.7. Changing Parameter Settings Manually x
4.1.7.1. RAM and ROM Parameter Settings
4.2. eSRAM Agilex™ FPGA IP x
4.2.1. Release Information for eSRAM Agilex™ FPGA IP 4.2.2. eSRAM System Features 4.2.3. eSRAM Agilex™ FPGA IP Parameters 4.2.4. eSRAM Agilex™ FPGA IP Interface Signals 4.2.5. eSRAM Timing Diagrams
4.2.2. eSRAM System Features x
4.2.2.1. eSRAM Specifications
4.3. FIFO IP x
4.3.1. Release Information for FIFO IP 4.3.2. Configuration Methods 4.3.3. Specifications 4.3.4. FIFO Functional Timing Requirements 4.3.5. SCFIFO ALMOST_EMPTY Functional Timing 4.3.6. FIFO Output Status Flag and Latency 4.3.7. FIFO Metastability Protection and Related Options 4.3.8. FIFO Synchronous Clear and Asynchronous Clear Effect 4.3.9. SCFIFO and DCFIFO Show-Ahead Mode 4.3.10. Different Input and Output Width 4.3.11. DCFIFO Timing Constraint Setting 4.3.12. Coding Example for Manual Instantiation 4.3.13. Gray-Code Counter Transfer at the Clock Domain Crossing 4.3.14. Guidelines for Embedded Memory ECC Feature 4.3.15. FIFO IP Parameters 4.3.16. Reset Scheme
4.3.3. Specifications x
4.3.3.1. Verilog HDL Prototype 4.3.3.2. VHDL Component Declaration 4.3.3.3. VHDL LIBRARY-USE Declaration 4.3.3.4. HDL Code from Parameterizable Macros Template 4.3.3.5. FIFO Signals 4.3.3.6. FIFO Parameter Settings
4.3.8. FIFO Synchronous Clear and Asynchronous Clear Effect x
4.3.8.1. Recovery and Removal Timing Violation Warnings when Compiling a DCFIFO
4.3.11. DCFIFO Timing Constraint Setting x
4.3.11.1. Embedded Timing Constraint 4.3.11.2. User Configurable Timing Constraint
4.3.11.2. User Configurable Timing Constraint x
4.3.11.2.1. SDC Commands
4.4. Shift Register (RAM-based) FPGA IP x
4.4.1. Release Information for Shift Register (RAM-based) FPGA IP 4.4.2. Shift Register (RAM-based) FPGA IP 4.4.3. Shift Register (RAM-based) FPGA IP General Description 4.4.4. Shift Register (RAM-based) FPGA IP Parameter Settings 4.4.5. Shift Register Ports and Parameters Setting
1. Agilex™ 7 Embedded Memory Overview
2. Agilex™ 7 Embedded Memory Architecture and Features
3. Agilex™ 7 Embedded Memory Design Considerations
4. Agilex™ 7 Embedded Memory IP References
5. Agilex™ 7 Embedded Memory Debugging
6. Agilex™ 7 Embedded Memory User Guide Archives
7. Document Revision History for the Agilex™ 7 Embedded Memory User Guide

4.3.11.2. User Configurable Timing Constraint

DCFIFO contains multi-bit gray-coded asynchronous clock domain crossing (CDC) paths which derives the DCFIFO fill-level. In order for the logic to work correctly, the value of the multi-bit must always be sampled as 1-bit change at a given latching clock edge.

In the physical world, flip-flops do not have the same data and clock path insertion delays. It is important for you to ensure and check the 1-bit change property is properly set. You can confirm this using the Fitter and check using the Timing Analyzer.

Timing Analyzer applies the following timing constraints for DCFIFO:

  • Paths crossing from write into read domain are defined from the delayed_wrptr_g to rs_dgwp registers. 
    • set from_node_list [get_keepers $hier_path|dcfifo_component|auto_generated|delayed_wrptr_g*]
    • set to_node_list [get_keepers $hier_path|dcfifo_component|auto_generated|rs_dgwp|dffpipe*|dffe*]
  • Paths crossing from read into write domain are defined from the rdptr_g and ws_dgrp registers. 
    • set from_node_list [get_keepers $hier_path|dcfifo_component|auto_generated|*rdptr_g*]
    • set to_node_list [get_keepers $hier_path|dcfifo_component|auto_generated|ws_dgrp|dffpipe*|dffe*]
  • For the above paths which cross between write and read domain, the following assignments apply: 
    • set_max_skew -from $from_node_list -to $to_node_list
-get_skew_value_from_clock_period src_clock_period -skew_value_multiplier 0.8
    • set_min_delay -from $from_node_list -to $to_node_list -100
    • set_max_delay -from $from_node_list -to $to_node_list 100
    • set_net_delay -from $from_node_list -to $to_node_list -max
-get_value_from_clock_period dst_clock_period -value_multiplier 0.8
  • The following set_net_delay on cross clock domain nets are for metastability:. 
    • set from_node_mstable_list [get_keepers $hier_path|dcfifo_component|auto_generated|ws_dgrp|dffpipe*|dffe*]
set to_node_mstable_list [get_keepers $hier_path|dcfifo_component|auto_generated|ws_dgrp|dffpipe*|dffe*] 
    • set from_node_mstable_list [get_keepers $hier_path|dcfifo_component|auto_generated|rs_dgwp|dffpipe*|dffe*]
set to_node_mstable_list [get_keepers $hier_path|dcfifo_component|auto_generated|rs_dgwp|dffpipe*|dffe*]
    • set_net_delay -from $from_node_list -to $to_node_list -max -get_value_from_clock_period dst_clock_period -value_multiplier 0.8

Timing Analyzer applies the following timing constraints for mix-width DCFIFO:

  • Paths crossing from write into read domain are defined from the delayed_wrptr_g to rs_dgwp registers. 
    • set from_node_list [get_keepers $hier_path|dcfifo_mixed_widths_component|auto_generated|delayed_wrptr_g*]

    • set to_node_list [get_keepers $hier_path|dcfifo_mixed_widths_component|auto_generated|rs_dgwp|dffpipe*|dffe*]
  • Paths crossing from read into write domain are defined from the rdptr_g and ws_dgrp registers. 
    • set from_node_list [get_keepers $hier_path|dcfifo_mixed_widths_component|auto_generated|*rdptr_g*]
    • set to_node_list [get_keepers $hier_path|dcfifo_mixed_widths_component|auto_generated|ws_dgrp|dffpipe*|dffe*]
  • For the above paths which cross between write and read domain, the following assignments apply: 
    • set_max_skew -from $from_node_list -to $to_node_list -get_skew_value_from_clock_period src_clock_period -skew_value_multiplier 0.8
    • set_min_delay -from $from_node_list -to $to_node_list -100
    • set_max_delay -from $from_node_list -to $to_node_list 100
    • set_net_delay -from $from_node_list -to $to_node_list -max -get_value_from_clock_period dst_clock_period -value_multiplier 0.8
  • The following set_net_delay on cross clock domain nets are for metastability: 
    • set from_node_mstable_list [get_keepers $hier_path|dcfifo_mixed_widths_component|auto_generated|ws_dgrp|dffpipe*|dffe*]
set to_node_mstable_list [get_keepers $hier_path|dcfifo_mixed_widths_component|auto_generated|ws_dgrp|dffpipe*|dffe*] 
    • set from_node_mstable_list [get_keepers $hier_path|dcfifo_mixed_widths_component|auto_generated|rs_dgwp|dffpipe*|dffe*]
set to_node_mstable_list [get_keepers $hier_path|dcfifo_mixed_widths_component|auto_generated|rs_dgwp|dffpipe*|dffe*]
    • set_net_delay -from $from_node_list -to $to_node_list -max - get_value_from_clock_period dst_clock_period -value_multiplier 0.8

Section Content
SDC Commands

Level Two Title