Embedded Memory User Guide: Agilex™ 5 FPGAs and SoCs

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ID 813901
Date 12/17/2024
Public
Document Table of Contents
Document Table of Contents x
1. Agilex™ 5 Embedded Memory Overview 2. Agilex™ 5 Embedded Memory Architecture and Features 3. Agilex™ 5 Embedded Memory Design Considerations 4. Agilex™ 5 Embedded Memory IP References 5. Agilex™ 5 Embedded Memory Debugging 6. Embedded Memory User Guide: Agilex™ 5 FPGAs and SoCs Archives 7. Document Revision History for the Embedded Memory User Guide: Agilex™ 5 FPGAs and SoCs
1. Agilex™ 5 Embedded Memory Overview x
1.1. Agilex™ 5 Embedded Memory Features 1.2. Agilex™ 5 Embedded Memory Block Signals
2. Agilex™ 5 Embedded Memory Architecture and Features x
2.1. Byte Enable in Agilex™ 5 Embedded Memory Blocks 2.2. Address Hold Support 2.3. Asynchronous Clear and Synchronous Clear 2.4. Memory Blocks Error Correction Code (ECC) Support 2.5. Agilex™ 5 Embedded Memory Clocking Modes 2.6. Agilex™ 5 Embedded Memory Configurations 2.7. Force-to-Zero 2.8. Coherent Read Memory 2.9. Freeze Logic 2.10. True Dual Port Dual Clock Emulator 2.11. Initial Value of Read and Write Address Registers 2.12. Timing/Power Optimization Feature in M20K Blocks
2.1. Byte Enable in Agilex™ 5 Embedded Memory Blocks x
2.1.1. Byte Enable Controls 2.1.2. Data Byte Output 2.1.3. Byte Enable Behavior
2.4. Memory Blocks Error Correction Code (ECC) Support x
2.4.1. Error Correction Code Truth Table 2.4.2. Parity Bit 2.4.3. ECC Parity Flip 2.4.4. ECC Read-During-Write Behavior
2.5. Agilex™ 5 Embedded Memory Clocking Modes x
2.5.1. Single Clock Mode 2.5.2. Read/Write Clock Mode 2.5.3. Input/Output Clock Mode 2.5.4. Asynchronous/Synchronous Clears in Clocking Modes 2.5.5. Output Read Data in Simultaneous Read/Write 2.5.6. Independent Clock Enables in Clocking Modes
2.6. Agilex™ 5 Embedded Memory Configurations x
2.6.1. Mixed-Width Port Configurations
2.8. Coherent Read Memory x
2.8.1. Forwarding Logic
2.10. True Dual Port Dual Clock Emulator x
2.10.1. True Dual-Port Mixed Port Read During Write New Data Emulation
3. Agilex™ 5 Embedded Memory Design Considerations x
3.1. Consider the Memory Block Selection 3.2. Consider the Concurrent Write 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. 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 3.3.1.3. Read-During-Write Data Output and Memory Location Behaviors
4. Agilex™ 5 Embedded Memory IP References x
4.1. On Chip Memory RAM and ROM Intel® FPGA IP Cores 4.2. FIFO Intel® FPGA IP 4.3. Shift Register (RAM-based) Intel® FPGA IP
4.1. On Chip Memory RAM and ROM Intel® FPGA IP Cores x
4.1.1. Release Information for RAM and ROM Intel® FPGA IPs 4.1.2. RAM: 1-PORT Intel® FPGA IP Parameters 4.1.3. RAM: 2-PORT Intel® FPGA IP Parameters 4.1.4. RAM: 4-PORT Intel® FPGA IP Parameters 4.1.5. ROM: 1-PORT Intel® FPGA IP Parameters 4.1.6. ROM: 2-PORT Intel® 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. FIFO Intel® FPGA IP x
4.2.1. Release Information for FIFO Intel® FPGA IP 4.2.2. Configuration Methods 4.2.3. Specifications 4.2.4. FIFO Functional Timing Requirements 4.2.5. SCFIFO ALMOST_EMPTY Functional Timing 4.2.6. FIFO Output Status Flag and Latency 4.2.7. FIFO Metastability Protection and Related Options 4.2.8. FIFO Synchronous Clear and Asynchronous Clear Effect 4.2.9. SCFIFO and DCFIFO Show-Ahead Mode 4.2.10. Different Input and Output Width 4.2.11. DCFIFO Timing Constraint Setting 4.2.12. Coding Example for Manual Instantiation 4.2.13. Instantiation Template 4.2.14. Design Example 4.2.15. Gray-Code Counter Transfer at the Clock Domain Crossing 4.2.16. Guidelines for Embedded Memory ECC Feature 4.2.17. FIFO Intel® FPGA IP Parameters 4.2.18. Reset Scheme
4.2.3. Specifications x
4.2.3.1. Verilog HDL Prototype 4.2.3.2. VHDL Component Declaration 4.2.3.3. VHDL LIBRARY-USE Declaration 4.2.3.4. HDL Code from Parameterizable Macros Template 4.2.3.5. FIFO Signals 4.2.3.6. FIFO Parameter Settings
4.2.8. FIFO Synchronous Clear and Asynchronous Clear Effect x
4.2.8.1. Recovery and Removal Timing Violation Warnings when Compiling a DCFIFO
4.2.11. DCFIFO Timing Constraint Setting x
4.2.11.1. Embedded Timing Constraint 4.2.11.2. User Configurable Timing Constraint
4.2.11.2. User Configurable Timing Constraint x
4.2.11.2.1. SDC Commands
4.3. Shift Register (RAM-based) Intel® FPGA IP x
4.3.1. Release Information for Shift Register (RAM-based) Intel® FPGA IP 4.3.2. Shift Register (RAM-based) Intel® FPGA IP Features 4.3.3. Shift Register (RAM-based) Intel® FPGA IP General Description 4.3.4. Shift Register (RAM-based) Intel® FPGA IP Parameter Settings 4.3.5. Shift Register Ports and Parameters Setting
1. Agilex™ 5 Embedded Memory Overview
2. Agilex™ 5 Embedded Memory Architecture and Features
3. Agilex™ 5 Embedded Memory Design Considerations
4. Agilex™ 5 Embedded Memory IP References
5. Agilex™ 5 Embedded Memory Debugging
6. Embedded Memory User Guide: Agilex™ 5 FPGAs and SoCs Archives
7. Document Revision History for the Embedded Memory User Guide: Agilex™ 5 FPGAs and SoCs

2.8. Coherent Read Memory

Coherent read memory allows you to read the latest data that will be written to a memory location in just one clock cycle. You will see the new data immediately, even if it is still being written. This feature works only for M20K blocks and is available when using a single clock configuration.

If you enable coherent read memory on M20K blocks with registered output and disable Force-to-Zero, the output register data will be held by the coherent read circuitry when the read enable (rden) signal is low (Refer to Coherent Read Memory Behavior for Agilex™ 5 Blocks figure and Simplified Block Diagram of Coherent Read Memory Circuitry figure for more details).

This circuitry acts like a loop (refer to the thicker connector lines), preventing it from fetching data from the M20K blocks' latch. When you clear the output register with asynchronous clear (aclr) or synchronous clear (sclr), the output stays at 0 until the next clock cycle after the rden signal is asserted again.

Figure 9. Coherent Read Memory Behavior for Agilex™ 5 BlocksThis figure demonstrates how coherent read memory works in Agilex™ 5 blocks when the feature is enabled, registered output is used, and Force-To-Zero is disabled. It specifically shows what happens when the M20K blocks do not read data while the clear signal is active.
If you enable the coherent read memory feature, you cannot use the following configurations:
  • Operating modes other than simple dual-port
  • Simple dual-port with different port width
  • Byte enable
  • ECC
  • Simple dual-port with more than 20-bit wide data
  • Dual clock configuration
Figure 10. Simplified Block Diagram of Coherent Read Memory Circuitry
Figure 11. Coherent Read Memory Behavior for Unregistered OutputThis figure shows the waveform of the coherent read memory when the output is unregistered.
Figure 12. Coherent Read Memory Behavior for Registered OutputThis figure shows the waveform of the coherent read memory when the output is registered.

Section Content
Forwarding Logic

Level Two Title