AN 796: Cyclone® V and Arria® V SoC Device Design Guidelines

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ID 683360
Date 3/30/2022
Public
Document Table of Contents
Document Table of Contents x
1. Overview of the Design Guidelines for Cyclone® V SoC FPGAs and Arria® V SoC FPGAs 2. Background: Comparison between Cyclone® V SoC FPGA and Arria® V SoC FPGA HPS Subsystems 3. Design Guidelines for HPS portion of SoC FPGAs 4. Board Design Guidelines for SoC FPGAs 5. Embedded Software Design Guidelines for SoC FPGAs A. Support and Documentation B. Additional Information
1. Overview of the Design Guidelines for Cyclone® V SoC FPGAs and Arria® V SoC FPGAs x
1.1. The SoC FPGA Designer’s Checklist 1.2. Overview of HPS Design Guidelines for SoC FPGA design 1.3. Overview of Board Design Guidelines for SoC FPGA Design 1.4. Overview of Embedded Software Design Guidelines for SoC FPGA Design
2. Background: Comparison between Cyclone® V SoC FPGA and Arria® V SoC FPGA HPS Subsystems x
2.1. Guidelines for Interconnecting the HPS and FPGA
2.1. Guidelines for Interconnecting the HPS and FPGA x
2.1.1. HPS-FPGA Bridges 2.1.2. FPGA-to-HPS SDRAM Access 2.1.3. Connecting Soft Logic to HPS Component
2.1.1. HPS-FPGA Bridges x
2.1.1.1. Lightweight HPS-to-FPGA Bridge 2.1.1.2. HPS-to-FPGA Bridge 2.1.1.3. FPGA-to-HPS Bridge
3. Design Guidelines for HPS portion of SoC FPGAs x
3.1. Start your SoC-FPGA design here 3.2. Design Considerations for Connecting Device I/O to HPS Peripherals and Memory 3.3. HPS Clocking and Reset Design Considerations 3.4. HPS EMIF Design Considerations 3.5. DMA Considerations 3.6. Managing Coherency for FPGA Accelerators 3.7. IP Debug Tools
3.1. Start your SoC-FPGA design here x
3.1.1. Recommended Starting Point for HPS-to-FPGA Interface Design 3.1.2. Determining your SoC FPGA Topology
3.2. Design Considerations for Connecting Device I/O to HPS Peripherals and Memory x
3.2.1. HPS Pin Assignment Design Considerations 3.2.2. HPS I/O Settings: Constraints and Drive Strengths
3.3. HPS Clocking and Reset Design Considerations x
3.3.1. HPS Clock Planning 3.3.2. Early Pin Planning and I/O Assignment Analysis 3.3.3. Pin Features and Connections for HPS JTAG, Clocks, Reset and PoR 3.3.4. Internal Clocks
3.4. HPS EMIF Design Considerations x
3.4.1. Considerations for Connecting HPS to SDRAM 3.4.2. HPS SDRAM I/O Locations 3.4.3. Integrating the HPS EMIF with the SoC FPGA Device 3.4.4. HPS Memory Debug 3.4.5. HPS Address Mirroring
3.5. DMA Considerations x
3.5.1. Choosing a DMA Controller 3.5.2. Optimizing DMA Master Bandwidth through HPS Interconnect 3.5.3. Timing Closure for FPGA Accelerators
3.6. Managing Coherency for FPGA Accelerators x
3.6.1. Cache Coherency 3.6.2. Coherency between FPGA Logic and HPS: Accelerator Coherency Port (ACP) 3.6.3. Data Size Impacts ACP Performance 3.6.4. Avoiding ACP Dependency Lockup 3.6.5. FPGA Access to ACP via AXI* or Avalon-MM 3.6.6. Data Alignment for ACP and L2 Cache ECC accesses
4. Board Design Guidelines for SoC FPGAs x
4.1. Board Bring Up Considerations 4.2. Boot and Configuration Design Considerations 4.3. HPS Power Design Considerations 4.4. Boundary Scan for HPS 4.5. Design Guidelines for HPS Interfaces
4.1. Board Bring Up Considerations x
4.1.1. Reserved BSEL Setting
4.2. Boot and Configuration Design Considerations x
4.2.1. Boot Design Considerations 4.2.2. Configuration 4.2.3. Reference Materials
4.2.1. Boot Design Considerations x
4.2.1.1. Boot Source 4.2.1.2. Select Desired Flash Device 4.2.1.3. BSEL Options 4.2.1.4. Boot Clock 4.2.1.5. CSEL Options 4.2.1.6. Selecting NAND Flash Devices 4.2.1.7. Determine Flash Programming Method 4.2.1.8. For QSPI and SD/MMC/eMMC Provide Flash Memory Reset 4.2.1.9. Selecting QSPI Flash Devices
4.2.2. Configuration x
4.2.2.1. Traditional Configuration 4.2.2.2. HPS Initiated Configuration
4.3. HPS Power Design Considerations x
4.3.1. Early System and Board Planning 4.3.2. Design Considerations for HPS and FPGA Power Supplies for SoC FPGA devices 4.3.3. Pin Connection Considerations for Board Designs 4.3.4. Power Analysis and Optimization
4.3.1. Early System and Board Planning x
4.3.1.1. Early Power Estimation
4.3.2. Design Considerations for HPS and FPGA Power Supplies for SoC FPGA devices x
4.3.2.1. Consider the Need to Power Down the FPGA Portion While Keeping the HPS Running 4.3.2.2. Consider Desired HPS Boot Clock Frequency
4.3.3. Pin Connection Considerations for Board Designs x
4.3.3.1. Device Power-Up
4.5. Design Guidelines for HPS Interfaces x
4.5.1. HPS EMAC PHY Interfaces 4.5.2. USB Interface Design Guidelines GUIDELINE: Design the board to support both USB PHY modes where the device supplies the clock versus where an external clock is the source. GUIDELINE: Ensure that the USB signal trace lengths are minimized. GUIDELINE: Ensure that signal integrity is considered. GUIDELINE: Design properly for OTG operation, when applicable. 4.5.3. QSPI Flash Interface Design Guidelines 4.5.4. SD/MMC and eMMC Card Interface Design Guidelines 4.5.5. NAND Flash Interface Design Guidelines 4.5.6. UART Interface Design Guidelines 4.5.7. I2C Interface Design Guidelines 4.5.8. SPI Interface Design Guidelines
4.5.1. HPS EMAC PHY Interfaces x
4.5.1.1. PHY Interfaces Connected Through HPS Dedicated I/O 4.5.1.2. PHY Interfaces Connected Through FPGA I/O 4.5.1.3. Common PHY Interface Design Considerations
4.5.1.1. PHY Interfaces Connected Through HPS Dedicated I/O x
4.5.1.1.1. RGMII
4.5.1.2. PHY Interfaces Connected Through FPGA I/O x
4.5.1.2.1. GMII/MII 4.5.1.2.2. Adapting to RGMII 4.5.1.2.3. Adapting to RMII 4.5.1.2.4. Adapting to SGMII 4.5.1.2.5. MDIO
4.5.1.3. Common PHY Interface Design Considerations x
4.5.1.3.1. Signal Integrity
5. Embedded Software Design Guidelines for SoC FPGAs x
5.1. Embedded Software for HPS: Design Guidelines 5.2. Flash Device Driver Design Considerations 5.3. SD Card Low Power Mode Design Considerations 5.4. HPS ECC Design Considerations 5.5. HPS SDRAM Considerations
5.1. Embedded Software for HPS: Design Guidelines x
5.1.1. Assembling the Components of Your Software Development Platform 5.1.2. Selecting an Operating System for Your Application 5.1.3. Assembling your Software Development Platform for Linux 5.1.4. Assembling a Software Development Platform for a Bare-Metal Application 5.1.5. Assembling your Software Development Platform for a Partner OS or RTOS 5.1.6. Choosing Boot Loader Software 5.1.7. Selecting Software Tools for Development, Debug and Trace
5.1.1. Assembling the Components of Your Software Development Platform x
5.1.1.1. Golden Hardware Reference Design
5.1.2. Selecting an Operating System for Your Application x
5.1.2.1. Linux or RTOS 5.1.2.2. Bare Metal 5.1.2.3. Using Symmetrical vs. Asymmetrical Multiprocessing (SMP vs. AMP) Modes
5.1.3. Assembling your Software Development Platform for Linux x
5.1.3.1. Golden System Reference Design (GSRD) for Linux 5.1.3.2. Source Code Management Considerations 5.1.3.3. GSRD for Linux Development Flow 5.1.3.4. GSRD for Linux Build Flow 5.1.3.5. Linux Device Tree Design Considerations
5.1.7. Selecting Software Tools for Development, Debug and Trace x
5.1.7.1. Select Software Build Tools 5.1.7.2. Select Software Debug Tools 5.1.7.3. Select Software Trace Tools
5.4. HPS ECC Design Considerations x
5.4.1. General ECC Design Considerations 5.4.2. System-Level ECC Control, Status and Interrupt Management 5.4.3. ECC for L2 Cache Data Memory 5.4.4. ECC for Flash Memory
5.5. HPS SDRAM Considerations x
5.5.1. Using the Preloader To Debug the HPS SDRAM 5.5.2. Access HPS SDRAM via the FPGA-to-SDRAM Interface
5.5.1. Using the Preloader To Debug the HPS SDRAM x
5.5.1.1. Enable Runtime Calibration Report 5.5.1.2. Change DLEVEL To Get More Debug Information 5.5.1.3. Enable Example Driver for HPS SDRAM 5.5.1.4. Change Data Pattern in Example Driver 5.5.1.5. Example Code to Write and Read from All Addresses 5.5.1.6. Read/Write to HPS Register in Preloader 5.5.1.7. Check HPS PLL Lock Status in Preloader
A. Support and Documentation x
A.1. Support A.2. Software Documentation
B. Additional Information x
B.1. Cyclone® V and Arria® V SoC Device Guidelines Revision History
1. Overview of the Design Guidelines for Cyclone® V SoC FPGAs and Arria® V SoC FPGAs
2. Background: Comparison between Cyclone® V SoC FPGA and Arria® V SoC FPGA HPS Subsystems
3. Design Guidelines for HPS portion of SoC FPGAs
4. Board Design Guidelines for SoC FPGAs
5. Embedded Software Design Guidelines for SoC FPGAs
A. Support and Documentation
B. Additional Information

4.5.2. USB Interface Design Guidelines

The Cyclone® V/ Arria® V SoC Hard Processor system can connect its embedded USB MACs directly to industry-standard USB 2.0 ULPI PHYs using the HPS Dedicated I/O that support 1.8V, 2.5V, 3.0V and 3.3V I/O standards. No FPGA routing resources are used and timing is fixed, which simplifies design. This guide describes the design guidelines covering all supported speeds of PHY operation: High-Speed (HS) 480 Mbps, Full-Speed (FS) 12 Mbps, and Low-Speed (LS) 1.5 Mbps.

Note: In Cyclone® V SoC U19 package (484 pins) only one USB controller is available.

GUIDELINE: Design the board to support both USB PHY modes where the device supplies the clock versus where an external clock is the source.

The interface between the ULPI MAC and PHY on the Cyclone® V/ Arria® V SoC consists of DATA[7:0], DIR and NXT from the MAC to the PHY and STP from the MAC to the PHY. Lastly a static clock of 60 MHz is driven from the PHY and is required for operation, including some register accesses from the HPS to the USB MAC. Ensure the PHY manufacturer recommendations for RESET and power-up are followed.

GUIDELINE: Ensure that the USB signal trace lengths are minimized.

At 60 MHz, the period is 16.67 ns and in that time, for example, the clock must travel from the external PHY to the MAC and then the data and control signals must travel from the MAC to the PHY. Because there is a round-trip delay, the maximum length of the CLK and ULPI signals are important. Based on timing data the maximum length is recommended to be less than 7 inches. This is based on a PHY with a 5 ns Tco specification. If the specification is slower the total length must be shortened accordingly.

GUIDELINE: Ensure that signal integrity is considered.

Signal integrity is also important but mostly on the CLK signal driven from the PHY to the MAC in the HPS subsystem. Because these signals are point-to-point with a maximum length, they can usually run unterminated but it is recommended to simulate the traces to make sure the reflections are minimized. Using the 50-ohm output setting from the FPGA is typically recommended unless the simulations show otherwise. A similar setting should be used from the PHY vendor if possible.

GUIDELINE: Design properly for OTG operation, when applicable.

When On-the-Go (OTG) functionality is used, the SoC can become a host or endpoint. When in host mode consider the power delivery, such as when you are supporting a USB Flash drive, or potentially a USB Hard Drive. These power requirements and reverse currents must be accounted for, typically by using external diodes and current limiters such as those used on the Cyclone® V SoC or Arria® V SoC development kits.

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