AN 886: Intel Agilex® 7 Device Design Guidelines

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ID 683634
Date 10/09/2023
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Document Table of Contents
Document Table of Contents x
1. Introduction to the Intel Agilex® 7 Device Design Guidelines 2. System Specification 3. Device Selection 4. Security Considerations 5. Design Entry 6. Board and Software Considerations 7. Design Implementation, Analysis, Optimization, and Verification 8. Debugging 9. Embedded Software Design Guidelines for Intel Agilex® 7 SoC FPGAs
1. Introduction to the Intel Agilex® 7 Device Design Guidelines x
1.1. Design Flow 1.2. Introduction to the Intel Agilex® 7 Device Design Guidelines Revision History
2. System Specification x
2.1. Design Specifications 2.2. Install Intel® Quartus® Prime Software 2.3. IP Selection 2.4. Simulation 2.5. Preparing for Design Entry 2.6. I/O Summary 2.7. Using Intel Agilex® 7 HPS in your Device 2.8. System Specification Revision History
2.3. IP Selection x
2.3.1. Evaluate Available HPS IP 2.3.2. Select Soft/Hardened IP and I/O Interfaces
2.5. Preparing for Design Entry x
2.5.1. Coding Styles and Design Recommendations 2.5.2. Platform Designer
3. Device Selection x
3.1. Device Variant 3.2. PLLs and Clock Routing 3.3. Logic, Memory, and Multiplier Density 3.4. I/O Pin Count, LVDS SERDES Channels, and Package Offering 3.5. Speed Grade 3.6. Device Migration 3.7. Device Selection Revision History
4. Security Considerations x
4.1. Security Considerations Revision History
5. Design Entry x
5.1. Design Entry for SoC Devices 5.2. Design Entry for FPGA-only Devices 5.3. Design Entry for NoC 5.4. EMIF Considerations 5.5. Nios® Software Processor IP 5.6. Transceiver Planning 5.7. Reconfiguration 5.8. Design Entry Revision History
5.1. Design Entry for SoC Devices x
5.1.1. Firewall Planning 5.1.2. Boot And Configuration Considerations 5.1.3. HPS Clocking and Reset Design Considerations 5.1.4. Reset Configuration 5.1.5. HPS Pin Multiplexing Design Considerations 5.1.6. HPS I/O Settings: Constraints and Drive Strengths 5.1.7. Design Guidelines for HPS Interfaces 5.1.8. Interfacing between the FPGA and HPS 5.1.9. Implementing the Intel Agilex® 7 HPS Component
5.1.2. Boot And Configuration Considerations x
5.1.2.1. Selecting HPS Boot Options 5.1.2.2. Configuration Sources 5.1.2.3. Remote System Update (RSU)
5.1.3. HPS Clocking and Reset Design Considerations x
5.1.3.1. HPS Clock Planning 5.1.3.2. Early Pin Planning and I/O Assignment Analysis 5.1.3.3. Pin Features and Connections for HPS Clocks, Reset and PoR 5.1.3.4. Direct to Factory Pin Support for Remote System Update (RSU) Feature 5.1.3.5. Internal Clocks
5.1.4. Reset Configuration x
5.1.4.1. HPS Peripheral Reset Management 5.1.4.2. System Reset Considerations
5.1.7. Design Guidelines for HPS Interfaces x
5.1.7.1. Design Considerations for Selecting PHY Interfaces 5.1.7.2. USB Interface Design Guidelines 5.1.7.3. SD/MMC and eMMC Card Interface Design Guidelines 5.1.7.4. Design Guidelines for Flash Interfaces 5.1.7.5. UART Interface Design Guidelines 5.1.7.6. I2C Interface Design Guidelines
5.1.7.1. Design Considerations for Selecting PHY Interfaces x
5.1.7.1.1. HPS EMAC PHY Interfaces 5.1.7.1.2. RMII and RGMII PHY Interfaces 5.1.7.1.3. PHY Interfaces Connected Through FPGA I/O 5.1.7.1.4. Consider Device Driver Availability 5.1.7.1.5. MDIO 5.1.7.1.6. Signal Integrity
5.1.7.4. Design Guidelines for Flash Interfaces x
5.1.7.4.1. NAND Flash Interface Design Guidelines
5.1.8. Interfacing between the FPGA and HPS x
5.1.8.1. Overview of HPS Memory-Mapped Interfaces 5.1.8.2. Recommended System Topologies 5.1.8.3. Recommended Starting Point for HPS-to-FPGA Interface Designs 5.1.8.4. Information on How to Configure and Use the Bridges
5.1.8.1. Overview of HPS Memory-Mapped Interfaces x
5.1.8.1.1. HPS-to-FPGA Bridge 5.1.8.1.2. Lightweight HPS-to-FPGA Bridge 5.1.8.1.3. FPGA-to-HPS Bridge 5.1.8.1.4. Interface Bandwidths
5.1.8.2. Recommended System Topologies x
5.1.8.2.1. System Level Cache Coherency GUIDELINE: Ensure that data accessed through the CCU fits in the 1 MB L2 cache to avoid thrashing overhead. GUIDELINE: For small buffers of data shared between the MPU and system masters, consider having the system master perform cacheable accesses to avoid overhead caused by cache flushing operations. 5.1.8.2.2. HPS Accesses to FPGA Fabric 5.1.8.2.3. MPU Sharing Data with FPGA 5.1.8.2.4. Examples of Cacheable and Non-Cacheable Data Accesses From the FPGA
5.2. Design Entry for FPGA-only Devices x
5.2.1. Clocking and Reset Design Considerations 5.2.2. I/O and Clock Planning
5.2.2. I/O and Clock Planning x
5.2.2.1. Making FPGA Pin Assignments 5.2.2.2. Early Pin Planning and I/O Assignment Analysis for the FPGA Device 5.2.2.3. I/O Features and Pin Connections 5.2.2.4. Clock and PLL Selection 5.2.2.5. PLL Feature Guidelines 5.2.2.6. Clock Control Features 5.2.2.7. I/O Simultaneous Switching Noise
5.2.2.3. I/O Features and Pin Connections x
5.2.2.3.1. I/O Signaling Type 5.2.2.3.2. Selectable Standards and Flexible I/O Banks 5.2.2.3.3. Dual-Purpose and Special Pin Connections 5.2.2.3.4. Intel Agilex® 7 I/O Features
5.2.2.5. PLL Feature Guidelines x
5.2.2.5.1. Clock Feedback Mode 5.2.2.5.2. Clock Outputs
5.3. Design Entry for NoC x
5.3.1. NoC Architecture Basics 5.3.2. NoC Design Flow 5.3.3. Configuring NoC IP 5.3.4. Instantiating NoC IP 5.3.5. NoC Assignments 5.3.6. NoC Physical Placement 5.3.7. Compilation 5.3.8. Simulation
5.4. EMIF Considerations x
5.4.1. Memory Interfaces 5.4.2. FPGA EMIF Design Considerations
5.5. Nios® Software Processor IP x
5.5.1. Nios® V 5.5.2. Nios® II
6. Board and Software Considerations x
6.1. Early System and Board Planning 6.2. Board Design Guidelines for Intel Agilex® 7 SoC FPGAs 6.3. Pin Connection Considerations for Board Design 6.4. Board Considerations Revision History
6.1. Early System and Board Planning x
6.1.1. SmartVID 6.1.2. Intel® FPGA Power and Thermal Calculator 6.1.3. Thermal Management and Design 6.1.4. Temperature Sensing for Thermal Management 6.1.5. Voltage Sensor 6.1.6. Device Power-Up 6.1.7. Power Pin Connections and Power Supplies 6.1.8. Planning for Device Configuration
6.1.7. Power Pin Connections and Power Supplies x
6.1.7.1. Decoupling Capacitors 6.1.7.2. PLL Board Design Guidelines 6.1.7.3. Transceiver Board Design Guidelines
6.1.8. Planning for Device Configuration x
6.1.8.1. Device Power Cycling and Reconfiguration 6.1.8.2. Configuration Scheme Selection 6.1.8.3. Configuration Features 6.1.8.4. Intel® Quartus® Prime Configuration Settings 6.1.8.5. Configuration Pin Connections
6.1.8.2. Configuration Scheme Selection x
6.1.8.2.1. Serial Configuration Devices 6.1.8.2.2. Intel® FPGA Download Cable
6.1.8.4. Intel® Quartus® Prime Configuration Settings x
6.1.8.4.1. Optional Configuration Pins 6.1.8.4.2. Dual Purpose Configuration Pins
6.1.8.5. Configuration Pin Connections x
6.1.8.5.1. Configuration Pin Voltage Level 6.1.8.5.2. Clock Trace Signal Integrity 6.1.8.5.3. JTAG Pins 6.1.8.5.4. MSEL Configuration Mode Pins 6.1.8.5.5. Other Configuration Pins
6.2. Board Design Guidelines for Intel Agilex® 7 SoC FPGAs x
6.2.1. Boundary Scan for HPS 6.2.2. Embedded Software Debugging and Trace
6.3. Pin Connection Considerations for Board Design x
6.3.1. Board-Related Intel® Quartus® Prime Settings 6.3.2. Signal Integrity Considerations 6.3.3. Board-Level Simulation and Advanced I/O Timing Analysis
6.3.1. Board-Related Intel® Quartus® Prime Settings x
6.3.1.1. Unused Pins
6.3.2. Signal Integrity Considerations x
6.3.2.1. High-Speed Board Design 6.3.2.2. Voltage Reference Pins 6.3.2.3. Simultaneous Switching Noise 6.3.2.4. I/O Termination
7. Design Implementation, Analysis, Optimization, and Verification x
7.1. Selecting a Synthesis Tool 7.2. Device Resource Utilization Reports 7.3. Intel® Quartus® Prime Messages 7.4. Timing Constraints and Analysis 7.5. Area and Timing Optimization 7.6. Preserving Performance and Reducing Compilation Time 7.7. Designing with Intel® Hyperflex™ 7.8. Simulation 7.9. Power Analysis 7.10. Power Optimization 7.11. Design Implementation, Analysis, Optimization, and Verification Revision History
7.4. Timing Constraints and Analysis x
7.4.1. Recommended Timing Optimization and Analysis Assignments
7.10. Power Optimization x
7.10.1. Device and Design Power Optimization Techniques 7.10.2. Intel® Quartus® Prime Power Optimization Techniques
7.10.1. Device and Design Power Optimization Techniques x
7.10.1.1. Device Speed Grade 7.10.1.2. Clock Power Management 7.10.1.3. Memory Power Reduction 7.10.1.4. I/O Power Guidelines
8. Debugging x
8.1. On-Chip Debug Overview 8.2. On-Chip Debugging Tools 8.3. Debugging Revision History
8.1. On-Chip Debug Overview x
8.1.1. Planning Guidelines for Debugging Tools
9. Embedded Software Design Guidelines for Intel Agilex® 7 SoC FPGAs x
9.1. Overview 9.2. Golden Hardware Reference Design (GHRD) 9.3. Define Software Requirements 9.4. Define Software Architecture 9.5. Selecting Software Tools 9.6. Choosing the Bootloader Software 9.7. Selecting an Operating System for Your Application 9.8. Assembling Your Software Development Platform for Linux* 9.9. Assembling your Software Development Platform for Partner OS or RTOS 9.10. Driver Considerations 9.11. Boot And Configuration Considerations 9.12. System Reset Considerations 9.13. Flash Considerations 9.14. Develop Application 9.15. Test and Validate 9.16. Embedded Software Design Guidelines Revision History
9.5. Selecting Software Tools x
9.5.1. Selecting Software Build Tools 9.5.2. Selecting Software Debug Tools 9.5.3. Selecting Software Trace Tools
9.7. Selecting an Operating System for Your Application x
9.7.1. Using Linux* or RTOS 9.7.2. Using the Bootloader as a Bare-Metal Framework 9.7.3. Using Symmetrical vs. Asymmetrical Multiprocessing (SMP vs. AMP) Modes
9.8. Assembling Your Software Development Platform for Linux* x
9.8.1. Golden System Reference Design (GSRD) for Linux* 9.8.2. Source Code Management Considerations
9.11. Boot And Configuration Considerations x
9.11.1. Configuration Sources 9.11.2. Configuration Flash 9.11.3. Configuration Clock 9.11.4. Selecting HPS Boot Options 9.11.5. HPS Boot Sources 9.11.6. Remote System Update (RSU)
9.13. Flash Considerations x
9.13.1. Flash Programming Method 9.13.2. Using a Single flash for Both FPGA Configuration and HPS Mass Storage
1. Introduction to the Intel Agilex® 7 Device Design Guidelines
2. System Specification
3. Device Selection
4. Security Considerations
5. Design Entry
6. Board and Software Considerations
7. Design Implementation, Analysis, Optimization, and Verification
8. Debugging
9. Embedded Software Design Guidelines for Intel Agilex® 7 SoC FPGAs

5.1.8.2.1. System Level Cache Coherency

Table 26.  Device Variant Checklist
Number Done? Checklist Item
1   Consider how many and which masters to use.
2   Determine how to manage cacheable accesses.
Consider how many masters and what masters to use:
  • MPU
  • DMA
  • Peripherals with master interfaces
  • Masters in FPGA connected to HPS

    Cache coherency is a fundamental topic to understand any time data must be shared amongst multiple masters in a system. In the context of a SoC device these masters can be the MPU, DMA, peripherals with master interfaces, and masters in the FPGA connected to the HPS. Since the MPU contains level 1 and level 2 cache controllers, it can hold more up-to-date contents than main memory in the system. The HPS supports two mechanisms to make sure masters in the system observe a coherent view of memory: ensuring main memory contains the latest value, or have masters access a directory-based CCU fabric using the ACE-Lite interface.

    The MPU can allocate buffers to be non-cacheable which ensures data is never cached by the L1 and L2 caches. The MPU can also access cacheable data and either flush it to main memory or copy it to a non-cacheable buffer before other masters attempt to access the data. Operating systems typically provide mechanisms for maintaining cache coherency both ways described above.

    Masters in the system access coherent data by either relying on the MPU to place data into main memory instead of having it cached, or by having the master in the system perform a cacheable access through the CCU. The mechanism you use depends on the size of the buffer of memory the master is accessing.

    For more information, refer to the Interfacing to the FPGA section.

GUIDELINE: Ensure that data accessed through the CCU fits in the 1 MB L2 cache to avoid thrashing overhead.

Since the L2 cache is 1 MB in size, if a master in the system frequently accesses buffers whose total size exceeds 1 MB, thrashing results.

Cache thrashing is a situation where the size of the data exceeds the size of the cache, causing the cache to perform frequent evictions and prefetches to main memory. Thrashing negates the performance benefits of caching the data.

In potential thrashing situation, it makes more sense to have the masters access non-cache coherent data and allow software executing on the MPU maintain the data coherency throughout the system.

GUIDELINE: For small buffers of data shared between the MPU and system masters, consider having the system master perform cacheable accesses to avoid overhead caused by cache flushing operations.

If a master in the system requires access to smaller coherent blocks of data then consider having the MPU access the buffer as cacheable memory and the master in the system perform cacheable accesses to the data. Cacheable accesses to the CCU through the ACE-Lite protocol supported by the FPGA-to-HPS bridge ensure that the master and MPU access the same copy of the data. By having the MPU use cacheable buffers and the system master performing cacheable accesses, software does not have to maintain system wide coherency ensuring both the MPU and system master observe the same copy of data.

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