SPRAD21F May   2022  – November 2024 AM620-Q1 , AM623 , AM625 , AM625-Q1 , AM625SIP , AM62A3 , AM62A3-Q1 , AM62A7 , AM62A7-Q1 , AM62P , AM62P-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
    1. 1.1 Application Note Usage Guidelines
      1. 1.1.1 Schematics Design Guidelines
      2. 1.1.2 Schematic Review Checklist
      3. 1.1.3 FAQ Reference for Application Note Usage Guidelines
    2. 1.2 AM62x Processor Family
      1. 1.2.1 AM625
      2. 1.2.2 AM623
      3. 1.2.3 AM625SIP
      4. 1.2.4 AM625-Q1
      5. 1.2.5 AM620-Q1
    3. 1.3 AM62Ax Processor Family
      1. 1.3.1 AM62A7
      2. 1.3.2 AM62A7-Q1
      3. 1.3.3 AM62A3
      4. 1.3.4 AM62A3-Q1
    4. 1.4 AM62Px Processor Family
      1. 1.4.1 AM62P
      2. 1.4.2 AM62P-Q1
  5. 2 Related Collaterals
    1. 2.1 Links to Commonly Available and Applicable Collaterals
      1. 2.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
      2. 2.1.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
      3. 2.1.3 AM62P / AM62P-Q1
    2. 2.2 Hardware Design Considerations for Custom Board
      1. 2.2.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
      2. 2.2.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
      3. 2.2.3 AM62P / AM62P-Q1
  6. 3 Processor Selection
    1. 3.1 Data Sheet Use Case and Version References in the Application Note
    2. 3.2 Device Selection and OPN
    3. 3.3 Peripheral Instance Naming Convention
    4. 3.4 Unused Peripherals
    5. 3.5 Device Ordering and Quality
    6. 3.6 Processor Selection Checklist
  7. 4 Power Architecture
    1. 4.1 Generating Supply Rails
      1. 4.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
        1. 4.1.1.1 Power Management IC (PMIC)
          1. 4.1.1.1.1 PMIC Checklist
          2. 4.1.1.1.2 Additional References
        2. 4.1.1.2 Discrete Power
          1. 4.1.1.2.1 DC/DC Converter
          2. 4.1.1.2.2 LDO
          3. 4.1.1.2.3 Discrete Power Checklist
      2. 4.1.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
        1. 4.1.2.1 PMIC
          1. 4.1.2.1.1 PMIC Checklist
        2. 4.1.2.2 Discrete Power
          1. 4.1.2.2.1 Discrete Power Checklist
      3. 4.1.3 AM62P / AM62P-Q1
        1. 4.1.3.1 PMIC
          1. 4.1.3.1.1 PMIC Checklist
        2. 4.1.3.2 Discrete Power
          1. 4.1.3.2.1 Discrete Power Checklist
    2. 4.2 Power Control and Circuit Protection
      1. 4.2.1 Load Switch (Power Switching)
        1. 4.2.1.1 Load Switch Checklist
      2. 4.2.2 eFuse IC (Power Switching and Protection)
  8. 5 General Recommendations
    1. 5.1 Processor Performance Evaluation Module (SK - Starter Kit)
      1. 5.1.1 Evaluation Module Checklist
    2. 5.2 Device-Specific (Processor-Specific, Processor-Family Specific) SK Versus Data Sheet
      1. 5.2.1 Notes About Component Selection
        1. 5.2.1.1 Series Resistor
        2. 5.2.1.2 Parallel Pull Resistor
        3. 5.2.1.3 Drive Strength Configuration
        4. 5.2.1.4 Data Sheet Recommendations
        5. 5.2.1.5 Processor IOs - External ESD Protection
        6. 5.2.1.6 Peripheral Clock Output Series Resistors
        7. 5.2.1.7 Component Selection Checklist
      2. 5.2.2 Additional Information Regarding Reuse of SK Design
        1. 5.2.2.1 Updated SK Schematic With Design, Review and CAD Notes Added
          1. 5.2.2.1.1 AM625 / AM623
          2. 5.2.2.1.2 AM625-Q1 / AM620-Q1
          3. 5.2.2.1.3 AM625SIP
          4. 5.2.2.1.4 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          5. 5.2.2.1.5 AM62P / AM62P-Q1
        2. 5.2.2.2 SK Design Files Reuse
          1. 5.2.2.2.1 Reuse of SK Design Checklist
    3. 5.3 Before Beginning the Design
      1. 5.3.1  Documentation
      2. 5.3.2  Processor Pin Attributes (Pinout) Verification
      3. 5.3.3  Device Comparison and IOSET
      4. 5.3.4  RSVD Reserved Pins (Signals)
      5. 5.3.5  Note on PADCONFIG Registers
      6. 5.3.6  Processor IO (Signal) Isolation for Fail-Safe Operation
      7. 5.3.7  Reference to Device-Specific SK
      8. 5.3.8  High-Speed Interface Design Guidelines
      9. 5.3.9  Recommended Current Source or Sink for LVCMOS (GPIO) Outputs
      10. 5.3.10 Connection of Slow Ramp Inputs or Capacitors to LVCMOS IOs (Inputs or Outputs)
      11. 5.3.11 Queries and Clarifications Related to Processor During Custom Board Design
      12. 5.3.12 Before Beginning the Design
      13. 5.3.13 Device Recommendations
  9. 6 Processor-Specific Recommendations
    1. 6.1 Common (Processor Start-Up) Connection
      1. 6.1.1 Power Supply
        1. 6.1.1.1 Supply for Core and Peripherals
          1. 6.1.1.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          2. 6.1.1.1.2 AM62P / AM62P-Q1
          3. 6.1.1.1.3 Additional Information
          4. 6.1.1.1.4 Processor Core and Peripheral Core Power Supply Checklist
          5. 6.1.1.1.5 Peripheral Analog Power Supply Checklist
        2. 6.1.1.2 Supply for IO Groups
          1. 6.1.1.2.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          2. 6.1.1.2.2 AM62P / AM62P-Q1
          3. 6.1.1.2.3 Additional Information
          4. 6.1.1.2.4 Supply for IO Groups Checklist
        3. 6.1.1.3 Supply for VPP (eFuse ROM Programming)
          1. 6.1.1.3.1 VPP Checklist
        4. 6.1.1.4 Supply Connection for Partial IO Mode (Low-Power) Configuration
          1. 6.1.1.4.1 Partial IO Used
          2. 6.1.1.4.2 Partial IO Unused
          3. 6.1.1.4.3 Data Sheet Reference for Power Sequence
          4. 6.1.1.4.4 Partial IO Low Mode Checklist
        5. 6.1.1.5 Additional Information
      2. 6.1.2 Capacitors for Supply Rails
        1. 6.1.2.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
        2. 6.1.2.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1 and AM62P / AM62P-Q1
        3. 6.1.2.3 Additional Information
          1. 6.1.2.3.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          2. 6.1.2.3.2 AM62P / AM62P-Q1
        4. 6.1.2.4 Capacitors for Supply Rails Checklist
      3. 6.1.3 Processor Clock
        1. 6.1.3.1 Clock Inputs
          1. 6.1.3.1.1 High Frequency Oscillator (MCU_OSC0_XI / MCU_OSC0_XO)
          2. 6.1.3.1.2 Low Frequency Oscillator (WKUP_LFOSC0_XI / WKUP_LFOSC0_XO)
          3. 6.1.3.1.3 EXT_REFCLK1 (External Clock Input to Main Domain)
          4. 6.1.3.1.4 Additional Information
          5. 6.1.3.1.5 Clock Input Checklist - MCU_OSC0
          6. 6.1.3.1.6 Clock Input Checklist - WKUP_LFOSC0
        2. 6.1.3.2 Clock Outputs
          1. 6.1.3.2.1 Clock Output Checklist
      4. 6.1.4 Processor Reset
        1. 6.1.4.1 External Reset Inputs
        2. 6.1.4.2 Reset Status Outputs
        3. 6.1.4.3 Additional Information
        4. 6.1.4.4 Processor Reset Input Checklist
        5. 6.1.4.5 Processor Reset Status Output Checklist
      5. 6.1.5 Configuration of Boot Modes (for Processor)
        1. 6.1.5.1 Processor Boot Mode Inputs Isolation Buffers Use Case and Optimization
        2. 6.1.5.2 Boot Mode Selection
          1. 6.1.5.2.1 Notes for USB Boot Mode
        3. 6.1.5.3 Boot Mode Implementation Approaches
        4. 6.1.5.4 Additional Information
        5. 6.1.5.5 Configuration of Boot Modes (for Processor) Checklist
    2. 6.2 Board Debug Using JTAG and EMU
      1. 6.2.1 JTAG and EMU Used
      2. 6.2.2 JTAG and EMU Not Used
      3. 6.2.3 Additional Information
      4. 6.2.4 Board Debug Using JTAG and EMU Checklist
  10. 7 Processor Peripherals
    1. 7.1 Supply Connections for IO Groups
      1. 7.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
      2. 7.1.2 AM62P / AM62P-Q1
      3. 7.1.3 Supply Connections for IO Groups Checklist
    2. 7.2 Memory Interface (DDRSS (DDR4 / LPDDR4), MMCSD (eMMC / SD / SDIO), OSPI / QSPI and GPMC)
      1. 7.2.1 DDR Subsystem (DDRSS)
        1. 7.2.1.1 DDR4 SDRAM (Double Data Rate 4 Synchronous Dynamic Random-Access Memory)
          1. 7.2.1.1.1 AM625 / AM623 / AM625-Q1 / AM620-Q1
            1. 7.2.1.1.1.1 Memory Interface Configuration
            2. 7.2.1.1.1.2 Routing Topology and Terminations
            3. 7.2.1.1.1.3 Resistors for Control and Calibration
            4. 7.2.1.1.1.4 Capacitors for the Power Supply Rails
            5. 7.2.1.1.1.5 Data Bit or Byte Swapping
            6. 7.2.1.1.1.6 VTT Termination Schematics Reference
            7. 7.2.1.1.1.7 DDR4 Implementation Checklist
          2. 7.2.1.1.2 AM625SIP
          3. 7.2.1.1.3 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          4. 7.2.1.1.4 AM62P / AM62P-Q1
        2. 7.2.1.2 LPDDR4 SDRAM (Low-Power Double Data Rate 4 Synchronous Dynamic Random-Access Memory)
          1. 7.2.1.2.1 AM625 / AM623 / AM625-Q1 / AM620-Q1
            1. 7.2.1.2.1.1 Memory Interface Configuration
            2. 7.2.1.2.1.2 Routing Topology and Terminations
            3. 7.2.1.2.1.3 Resistors for Control and Calibration
            4. 7.2.1.2.1.4 Capacitors for the Power Supply Rails
            5. 7.2.1.2.1.5 Data Bit or Byte Swapping
            6. 7.2.1.2.1.6 LPDDR4 Implementation Checklist
          2. 7.2.1.2.2 AM625SIP
          3. 7.2.1.2.3 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1 and AM62P / AM62P-Q1
            1. 7.2.1.2.3.1 Memory Interface Configuration
            2. 7.2.1.2.3.2 Routing Topology and Terminations
            3. 7.2.1.2.3.3 Resistors for Control and Calibration
            4. 7.2.1.2.3.4 Capacitors for the Power Supply Rails
            5. 7.2.1.2.3.5 Data Bit or Byte Swapping
            6. 7.2.1.2.3.6 LPDDR4 Implementation Checklist
      2. 7.2.2 Multi-Media Card/Secure Digital (MMCSD)
        1. 7.2.2.1 MMC0 - eMMC (Embedded Multi-Media Card) Interface
          1. 7.2.2.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
            1. 7.2.2.1.1.1 IO Power Supply
            2. 7.2.2.1.1.2 eMMC (Attached Device) Reset
            3. 7.2.2.1.1.3 Signals Connection
            4. 7.2.2.1.1.4 Capacitors for the Power Supply Rails
            5. 7.2.2.1.1.5 MMC0 (eMMC) Checklist for AM62x and AM62Ax
          2. 7.2.2.1.2 AM62P / AM62P-Q1
            1. 7.2.2.1.2.1 MMC0 Used
              1. 7.2.2.1.2.1.1 IO Power Supply
              2. 7.2.2.1.2.1.2 eMMC (Attached Device) Reset
              3. 7.2.2.1.2.1.3 Signals Connection
              4. 7.2.2.1.2.1.4 Capacitors for the Power Supply Rails
            2. 7.2.2.1.2.2 MMC0 Not Used
            3. 7.2.2.1.2.3 MMC0 (eMMC) Checklist for AM62P
          3. 7.2.2.1.3 Additional Information on eMMC PHY
          4. 7.2.2.1.4 MMC0 – SD (Secure Digital) Card Interface
        2. 7.2.2.2 MMC1/MMC2 – SD (Secure Digital) Card Interface
          1. 7.2.2.2.1 IO Power Supply
          2. 7.2.2.2.2 SD Card Supply Reset and Boot Configuration
          3. 7.2.2.2.3 Signals Connection
          4. 7.2.2.2.4 ESD Protection
          5. 7.2.2.2.5 Capacitors for the Power Supply Rails
          6. 7.2.2.2.6 MMC1 SD Card Interface Checklist
        3. 7.2.2.3 MMC1 / MMC2 SDIO (Embedded) Interface
          1. 7.2.2.3.1 IO Power Supply
          2. 7.2.2.3.2 Signals Connection
          3. 7.2.2.3.3 MMC2 SDIO (Embedded) Interface Checklist
        4. 7.2.2.4 Additional Information
      3. 7.2.3 Octal Serial Peripheral Interface (OSPI) and Quad Serial Peripheral Interface (QSPI)
        1. 7.2.3.1 IO Power Supply
        2. 7.2.3.2 OSPI / QSPI Reset
        3. 7.2.3.3 Signals Connection
        4. 7.2.3.4 Loopback Clock
        5. 7.2.3.5 Interface to Multiple Devices
        6. 7.2.3.6 Capacitors for the Power Supply Rails
        7. 7.2.3.7 OSPI / QSPI Implementation Checklist
      4. 7.2.4 General-Purpose Memory Controller (GPMC)
        1. 7.2.4.1 IO Power Supply
        2. 7.2.4.2 GPMC Interface
        3. 7.2.4.3 Memory (Attached Device) Reset
        4. 7.2.4.4 Signals Connection
          1. 7.2.4.4.1 GPMC NAND
        5. 7.2.4.5 Capacitors for the Power Supply Rails
        6. 7.2.4.6 GPMC Interface Checklist
    3. 7.3 External Communication Interface (Ethernet (CPSW3G), USB2.0, PRUSS, UART and Controller Area Network (CAN))
      1. 7.3.1 Ethernet Interface Using CPSW3G (Common Platform Ethernet Switch 3-Port Gigabit)
        1. 7.3.1.1  IO Power Supply
        2. 7.3.1.2  Ethernet PHY Reset
        3. 7.3.1.3  Ethernet PHY Pin Strapping
        4. 7.3.1.4  Ethernet PHY (and MAC) Operation and Media Independent Interface (MII) Clock
          1. 7.3.1.4.1 Crystal
          2. 7.3.1.4.2 Oscillator
          3. 7.3.1.4.3 Processor Clock Output (CLKOUT0)
        5. 7.3.1.5  MAC (Data, Control and Clock) Interface Signals Connection
        6. 7.3.1.6  External Interrupt (EXTINTn)
          1. 7.3.1.6.1 External Interrupt (EXTINTn) Checklist
        7. 7.3.1.7  MAC (Media Access Controller) to MAC Interface
        8. 7.3.1.8  MDIO (Management Data Input/Output) Interface
        9. 7.3.1.9  Ethernet MDI (Medium Dependent Interface) Including Magnetics
        10. 7.3.1.10 Capacitors for the Power Supply Rails
        11. 7.3.1.11 Ethernet Interface Checklist
      2. 7.3.2 Universal Serial Bus (USB2.0)
        1. 7.3.2.1 USBn (n = 0-1) Used
          1. 7.3.2.1.1 USB Host Interface
          2. 7.3.2.1.2 USB Device Interface
          3. 7.3.2.1.3 USB Dual-Role-Device Interface
          4. 7.3.2.1.4 USB Type-C®
        2. 7.3.2.2 USBn (n = 0-1) Not Used
        3. 7.3.2.3 Additional Information
        4. 7.3.2.4 USB Interface Checklist
      3. 7.3.3 Programmable Real-Time Unit Subsystem (PRUSS)
        1. 7.3.3.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
          1. 7.3.3.1.1 PRU Subsystem
          2. 7.3.3.1.2 PRUSS Checklist
        2. 7.3.3.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1 and AM62P / AM62P-Q1
      4. 7.3.4 Universal Asynchronous Receiver/Transmitter (UART)
        1. 7.3.4.1 Universal Asynchronous Receiver/Transmitter (UART) Checklist
      5. 7.3.5 Controller Area Network (CAN)
        1. 7.3.5.1 Controller Area Network Checklist
    4. 7.4 On-board Synchronous Communication Interface (MCSPI, MCASP and I2C)
      1. 7.4.1 Multichannel Serial Peripheral Interface (MCSPI) and Multichannel Audio Serial Ports (MCASP)
        1. 7.4.1.1 MCSPI Checklist
        2. 7.4.1.2 MCASP Checklist
      2. 7.4.2 Inter-Integrated Circuit (I2C)
        1. 7.4.2.1 I2C Open-drain Output Type Buffer Checklist
        2. 7.4.2.2 I2C Emulated Open-drain Output Type Buffer Checklist
    5. 7.5 User Interface (CSIRX0, DPI, OLDI, DSI), GPIO and Hardware Diagnostics
      1. 7.5.1 Camera Serial Interface (CSI-Rx (CSI-2 port, CSIRX0 Instance))
        1. 7.5.1.1 CSIRX0 Used
        2. 7.5.1.2 CSIRX0 Not Used
        3. 7.5.1.3 CSI Checklist
      2. 7.5.2 Display Subsystem
        1. 7.5.2.1 Display Parallel Interface (DPI)
          1. 7.5.2.1.1 AM625 / AM623 / AM625SIP / AM625-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1 and AM62P / AM62P-Q1
            1. 7.5.2.1.1.1 IO Power Supply
            2. 7.5.2.1.1.2 DPI (Attached Device) Reset
            3. 7.5.2.1.1.3 Connection
            4. 7.5.2.1.1.4 Signals Connection
            5. 7.5.2.1.1.5 Capacitors for the Power Supply Rails
            6. 7.5.2.1.1.6 DPI Checklist
          2. 7.5.2.1.2 AM620-Q1
        2. 7.5.2.2 Open LVDS Display Interface (OLDI)
          1. 7.5.2.2.1 AM625 / AM623 / AM625SIP / AM625-Q1 and AM62P / AM62P-Q1
            1. 7.5.2.2.1.1 OLDI0 Used
              1. 7.5.2.2.1.1.1 IO Power Supply
              2. 7.5.2.2.1.1.2 OLDI (Attached Device) Reset
              3. 7.5.2.2.1.1.3 OLDI Interface Compatibility
              4. 7.5.2.2.1.1.4 Capacitors for the Power Supply Rails
              5. 7.5.2.2.1.1.5 OLDI Checklist
            2. 7.5.2.2.1.2 OLDI0 Not Used
            3. 7.5.2.2.1.3 Additional Information
          2. 7.5.2.2.2 AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
        3. 7.5.2.3 Display Serial Interface (DSI)
          1. 7.5.2.3.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 and AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
          2. 7.5.2.3.2 AM62P / AM62P-Q1
            1. 7.5.2.3.2.1 DSITX0 Used
              1. 7.5.2.3.2.1.1 DSITX0 Checklist
            2. 7.5.2.3.2.2 DSITX0 Not Used
      3. 7.5.3 General Purpose Input/Output (GPIO)
        1. 7.5.3.1 Availability of CLKOUT on Processor GPIO
        2. 7.5.3.2 Connection and External Buffering
        3. 7.5.3.3 Additional Information
        4. 7.5.3.4 GPIO Checklist
      4. 7.5.4 On-board Hardware Diagnostics
        1. 7.5.4.1 Monitoring of On-board Supply Voltages Using Processor Voltage Monitors
          1. 7.5.4.1.1 Voltage Monitor Pins Used
            1. 7.5.4.1.1.1 Voltage Monitor Checklist
          2. 7.5.4.1.2 Voltage Monitor Pins Not Used
        2. 7.5.4.2 Internal Temperature Monitoring
          1. 7.5.4.2.1 Internal Temperature Monitoring Checklist
        3. 7.5.4.3 Connection of Error Signal Output (MCU_ERRORn)
        4. 7.5.4.4 High Frequency Oscillator (MCU_OSC0) Clock Loss Detection
    6. 7.6 Verifying Board Level Design Issues
      1. 7.6.1 Processor Pin Configuration Using PinMux Tool
      2. 7.6.2 Schematics Configurations
      3. 7.6.3 Connecting Supply Rails to Pullups
      4. 7.6.4 Peripheral (Subsystem) Clock Outputs
      5. 7.6.5 General Board Bring-up and Debug
        1. 7.6.5.1 Clock Output for Board Bring-Up, Test, or Debug
        2. 7.6.5.2 Additional Information
        3. 7.6.5.3 General Board Bring-up and Debug Checklist
  11. 8 Layout Notes (Added on the Schematic)
    1. 8.1 Layout Checklist
  12. 9 Custom Board Design Simulation
  13. 10Additional References
    1. 10.1 FAQ Covering AM6xx Processor Family
    2. 10.2 FAQs - Processor Product Family Wise and Sitara Processor Families
    3. 10.3 Processor Attached Devices
  14. 11Summary
  15. 12References
    1. 12.1 AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1
    2. 12.2 AM62A7 / AM62A3 / AM62A7-Q1 / AM62A3-Q1
    3. 12.3 AM62P / AM62P-Q1
    4. 12.4 Common for all Processor Families
    5. 12.5 Master List of Available FAQs - Processor Family Wise
    6. 12.6 Master List of Available FAQs - Sitara Processor Families
    7. 12.7 FAQs Including Software Related
    8. 12.8 FAQs for Attached Devices
  16. 13Terminology
  17. 14Revision History

7.3.2.4 USB Interface Checklist

General

Review and verify the following for the custom schematic design:

  1. Above section including relevant application notes and FAQ links
  2. Pin connectivity requirements, pin attributes and signal description
  3. Referenced specific standard for electrical characteristics, timing parameters and any additional available information
  4. Required USB interface configuration (Host or Device) and recommended connections
  5. USB VBUS design guidelines based on the USB interface configuration. USBn_VBUS connection is optional for Host configuration. Connecting 5V supply from the USB connector directly to the USBn_VBUS pin is not allowed or recommended. Changing the data sheet VBUS recommended divider value is not allowed or recommended. VBUS fail-safe capability of the IO is valid only when the recommended divider values are implemented
  6. Connection of recommended IO calibration resistor
  7. Connection of the recommended USB supplies including filtering
  8. Direct connection of the USB signals
  9. Common-mode chokes may be used for EMI / EMC control. Adding common-mode choke may reduce the signal amplitude and degrade performance. Add provision to bypass the CMC using 0Ω resistors
  10. Marking of differential signals and the differential impedance
  11. Implementation of USB power switch when USB interface is configured as HOST
  12. USB power switch enable control using DRVVBUS (internal pulldown is enabled during reset)
  13. Connection of the power switch OC output to processor IO
  14. Connection of the USB signals to the USB connector
  15. Provision for recommended capacitors on the USB VBUS pin of the USB connector
  16. Provision for required external ESD protections for the USB interface
  17. In case USB boot is implemented, verify the errata, supported interface configuration, USB port and the connections

Schematic Review

Follow the below list for the custom schematic design:

  1. USB interface connection matches the required USB interface configuration (Host or Device). Compare the interface connection with the SK
  2. External ESD protection and CMC implementation with provision to bypass using 0Ω resistors
  3. VBUS voltage divider values (follow data sheet) and tolerance (1%). Follow the data sheet recommendations. Use of multiple resistors is allowed provided the value, tolerance and ratio is maintained
  4. VBUS capacitor values used versus requirements (refer SK)
  5. Power switch enable connection (in case processor USBn_DRVVBUS is used, pullup is not recommended or allowed since the DRVVBUS has an internal pulldown enabled)
  6. Connection of power switch OC output to the processor IO and IO level compatibility
  7. Supply rails connected follow the ROC

Additional

  1. In case Type-C USB interface is implemented, get the implementation verified by the relevant BU/PL
  2. A filtered supply (ferrite and capacitors) is used for VDDA_CORE_USB and VDDA_1P8_USB. VDDA_3P3_USB can be connected to the 3V3 SYS voltage. Refer specific and latest SK for implementation as filters are being continuously optimized
  3. Verify fail-safe operation of USB interface. Applying an external interface signal before supply ramps can cause voltage feed and affect the processor performance
  4. When a CMC is used on the USB data lines, verify the connections including the polarity. Reversing the polarity may short the data signals
  5. DNI USBx_DRVVBUS pullup and pulldown to implement wakeup from deep sleep