Embedded Memory User Guide: Agilex™ 5 FPGAs and SoCs

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ID 813901
Date 4/01/2024
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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. 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
2. Agilex™ 5 Embedded Memory Architecture and Features x
2.1. Byte Enable in Agilex™ 5 Embedded Memory Blocks 2.2. Address Clock Enable 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. Parity Bit 2.4.2. ECC Parity Flip 2.4.3. ECC Read-During-Write Behavior 2.4.4. Error Correction Code Truth Table
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
3. Agilex™ 5 Embedded Memory Design Considerations x
3.1. Consider the Memory Block Selection 3.2. Consider the Concurrent Read Behavior 3.3. Customize Read-During-Write Behavior 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. Customize Read-During-Write Behavior x
3.3.1. Same-Port Read-During-Write Mode 3.3.2. Mixed-Port Read-During-Write Mode
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. Document Revision History for the Embedded Memory User Guide: Agilex™ 5 FPGAs and SoCs

2.8. Coherent Read Memory

The coherent read memory feature allows you to read out the output data that will be written into the same memory content in a single clock cycle. In other words, you will experience the new data (flow through) behavior during the read-during-write operation. This feature is applicable only for M20K blocks and supported only in single clock configuration.

If the M20K blocks are configured with coherent read memory feature enabled with registered output and Force-to-Zero feature disabled, the output register data will be held through 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 behaves like a loop instead of fetching data from the latch of the M20K blocks. When asynchronous clear (aclr) or synchronous clear (sclr) is asserted to clear the output register of M20K blocks, the output remains as 0 until the next clock cycle, after the rden signal is asserted again.

Figure 9. Coherent Read Memory Behavior for Agilex™ 5 BlocksThis figure shows an example of the coherent read memory behavior when coherent read memory feature is enabled with registered output and Force-To-Zero feature is disabled if the M20K blocks does not read when the clear signal is asserted high.
If you engage 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