SPRACU5C June   2021  – September 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
    1. 1.1 AM64x Processor Family
    2. 1.2 AM243x Processor Family
  5. 2 Related Collaterals
    1. 2.1 Hardware Design Guide
  6. 3 Processor Selection
    1. 3.1 Data Sheet
    2. 3.2 Peripheral Instance Naming Convention
    3. 3.3 Processor Ordering and Quality
  7. 4 Power Architecture
    1. 4.1 Generating Supply Rails
      1. 4.1.1 PMIC (Power Management IC)
        1. 4.1.1.1 Additional Reference
      2. 4.1.2 Discrete Power
        1. 4.1.2.1 DC/DC Converter
        2. 4.1.2.2 LDO
    2. 4.2 Power
      1. 4.2.1 Load Switch
      2. 4.2.2 eFuse
  8. 5 General Recommendations
    1. 5.1 Processor Performance Evaluation Module (EVM)
    2. 5.2 EVM Versus Data Sheet
      1. 5.2.1 Note About Component Selection
        1. 5.2.1.1 Series Resistor
        2. 5.2.1.2 Parallel Termination
        3. 5.2.1.3 External ESD Protection
      2. 5.2.2 Additional Information
    3. 5.3 Before You Begin The Design
      1. 5.3.1  Documentation
      2. 5.3.2  Processor Pinout Verification
      3. 5.3.3  IOSET
      4. 5.3.4  Note on PADCONFIG Register
      5. 5.3.5  Signal Isolation for Fail-Safe Operation
      6. 5.3.6  Reference to EVM or SK
      7. 5.3.7  Board Design - Layers Optimization
      8. 5.3.8  Termination of Unused Processor Pins
      9. 5.3.9  Naming of Peripheral Instances
      10. 5.3.10 High-Speed Interface Design Guidelines
      11. 5.3.11 Voltage and Thermal Manager (VTM) Module
      12. 5.3.12 Allowed GPIO Current Source or Sink
      13. 5.3.13 Connection of Capacitor to LVCMOS Type IO (Input or Output)
      14. 5.3.14 Processor Related Queries and Clarifications
  9. 6 Processor Specific Recommendations
    1. 6.1 Common (Processor Start-Up) Connection
      1. 6.1.1 Power Supply
        1. 6.1.1.1 Supplies for Core and Peripherals
          1. 6.1.1.1.1 Power Supply Ramp (Slew Rate) Requirement and Dynamic Voltage Scaling
        2. 6.1.1.2 Supply for IO Groups
        3. 6.1.1.3 Supply for VPP (eFuse ROM Programming)
        4. 6.1.1.4 Additional Information
      2. 6.1.2 Capacitors for Supply Rails
        1. 6.1.2.1 Additional Information
      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 External Clock Input to Main Domain (EXT_REFCLK1)
          3. 6.1.3.1.3 Additional Information
        2. 6.1.3.2 Clock Output
      4. 6.1.4 Processor Reset
        1. 6.1.4.1 Reset Inputs
        2. 6.1.4.2 Reset Status Outputs
        3. 6.1.4.3 Additional Information
      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 Bootmode Selection
          1. 6.1.5.2.1 Notes for USB Boot Mode
        3. 6.1.5.3 Additional Information
    2. 6.2 Board Debug Using JTAG and EMU
      1. 6.2.1 Additional Information
  10. 7 Processor Peripherals
    1. 7.1 Power Supply Connections for IO Groups
    2. 7.2 Memory Interface (DDR4, LPDDR4, MMCSD (eMMC/SD/SDIO), OSPI/QSPI and GPMC)
      1. 7.2.1 DDR Subsystem (DDRSS)
        1. 7.2.1.1 Double Data Rate 4 (DDR4)
          1. 7.2.1.1.1 Interface Configuration
          2. 7.2.1.1.2 Routing Topology and Terminations
          3. 7.2.1.1.3 Resistors for Control and Calibration
          4. 7.2.1.1.4 Capacitors for the Power Supply Rails
          5. 7.2.1.1.5 Data Bit or Byte Swapping
        2. 7.2.1.2 Low-Power Double Data Rate 4 (LPDDR4)
          1. 7.2.1.2.1 Interface Configuration
          2. 7.2.1.2.2 Routing Topology and Terminations
          3. 7.2.1.2.3 Resistors for Control and Calibration
          4. 7.2.1.2.4 Capacitors for the Power Supply Rails
          5. 7.2.1.2.5 Data Bit or Byte Swapping
      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 MMC0 Used
            1. 7.2.2.1.1.1 IO Power Supply
            2. 7.2.2.1.1.2 eMMC Reset
            3. 7.2.2.1.1.3 Signals Termination
            4. 7.2.2.1.1.4 Capacitors for the Power Supply Rails
          2. 7.2.2.1.2 MMC0 Not Used
          3. 7.2.2.1.3 Additional Information
        2. 7.2.2.2 MMC1 – Secure Digital (SD) Card Interface
          1. 7.2.2.2.1 IO Power Supply
          2. 7.2.2.2.2 SD Card Reset and Boot
          3. 7.2.2.2.3 Signals Termination
          4. 7.2.2.2.4 ESD Protection
          5. 7.2.2.2.5 Capacitors for the Power Supply Rails
        3. 7.2.2.3 Additional Information
      3. 7.2.3 Octal Serial Peripheral Interface (OSPI) or 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 Termination
        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
      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 Reset
        4. 7.2.4.4 Signals Termination
        5. 7.2.4.5 Capacitors for the Power Supply Rails
    3. 7.3 External Communication Interface (Ethernet (CPSW3G and PRU_ICSSG), USB2.0, USB3.0 (SERDES), PCIe (SERDES), UART and CAN)
      1. 7.3.1 Ethernet Interface (CPSW3G and PRU_ICSSG)
        1. 7.3.1.1  IO Power Supply
        2. 7.3.1.2  Media Independent Interface (MAC side)
          1. 7.3.1.2.1 Common Platform Ethernet Switch 3-Port Gigabit (CPSW3G)
          2. 7.3.1.2.2 Programmable Real-Time Unit and Industrial Communication Subsystem - Gigabit (PRU_ICSSG)
          3. 7.3.1.2.3 Additional Information
        3. 7.3.1.3  Usage of SysConfig-PinMux Tool
        4. 7.3.1.4  EPHY Reset
        5. 7.3.1.5  Ethernet PHY Pin Strapping
        6. 7.3.1.6  Ethernet PHY (and MAC) Operation and Media Independent Interface (MII) Clock
          1. 7.3.1.6.1 Crystal
          2. 7.3.1.6.2 Oscillator
          3. 7.3.1.6.3 Processor Clock Output (CLKOUT0)
        7. 7.3.1.7  MAC (Data, Control and Clock) Interface Signals Termination
        8. 7.3.1.8  MAC (Media Access Controller) to MAC Interface
        9. 7.3.1.9  Management Data Input/Output (MDIO) Interface
          1. 7.3.1.9.1 MDIO Interface Mode
        10. 7.3.1.10 Ethernet Medium Dependent Interface (MDI) Including Magnetics
        11. 7.3.1.11 Capacitors for the Power Supply Rails
      2. 7.3.2 Universal Serial Bus (USB2.0)
        1. 7.3.2.1 USB 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 USB Not Used
        3. 7.3.2.3 Additional Information
      3. 7.3.3 Serializer/Deserializer (SERDES)
        1. 7.3.3.1 SERDES0 Used
          1. 7.3.3.1.1 USB3SS0 - USB3.0 Super Speed Interface Configuration
            1. 7.3.3.1.1.1 Signal Interface
              1. 7.3.3.1.1.1.1 USB3.0 Super Speed Interface
                1. 7.3.3.1.1.1.1.1 USB3.0 Super Speed Interface Operating Mode Configuration
            2. 7.3.3.1.1.2 Unused SERDES Clock Termination
            3. 7.3.3.1.1.3 Additional Information
          2. 7.3.3.1.2 Peripheral Component Interconnect Express (PCIe) Interface Configuration
            1. 7.3.3.1.2.1 Clock Configuration for PCIe Operating Modes
            2. 7.3.3.1.2.2 Signal Interface Termination
            3. 7.3.3.1.2.3 PCIe Clock (REFCLK) Source
            4. 7.3.3.1.2.4 Hardware Reset (Fundamental Reset)
            5. 7.3.3.1.2.5 PCIe Clock Request (PCIE0_CLKREQn) Signal
            6. 7.3.3.1.2.6 Connecting PCIe Interface Signals
        2. 7.3.3.2 SERDES0 Not Used
      4. 7.3.4 Universal Asynchronous Receiver/Transmitter (UART)
      5. 7.3.5 Controller Area Network (CAN)
    4. 7.4 On-Board Synchronous Communication Interface (MCSPI and I2C)
      1. 7.4.1 Multichannel Serial Peripheral Interface (MCSPI)
      2. 7.4.2 Inter-Integrated Circuit (I2C)
    5. 7.5 Analog to Digital Converter (ADC)
      1. 7.5.1 ADC0 Used
      2. 7.5.2 ADC0 Not Used
    6. 7.6 GPIO and Hardware Diagnostics
      1. 7.6.1 General Purpose Input/Output (GPIO)
        1. 7.6.1.1 Termination and External Buffering
        2. 7.6.1.2 GPIO Multiplexed With MMC Interface
        3. 7.6.1.3 Additional Information
      2. 7.6.2 Internal Hardware Diagnostics
        1. 7.6.2.1 Monitoring of On-Board Supply Voltages Using Processor
          1. 7.6.2.1.1 Voltage Monitor Pins When Used
          2. 7.6.2.1.2 Voltage Monitor Pins Not Used
        2. 7.6.2.2 Internal Temperature Monitoring
        3. 7.6.2.3 Termination of Error Signal Output (MCU_SAFETY_ERRORn)
        4. 7.6.2.4 High Frequency Oscillator (MCU_OSC0) Clock Loss Detection
    7. 7.7 Verifying Board Level Design Issues
      1. 7.7.1 Processor Pin Configuration Using Pinmux Tool
      2. 7.7.2 Schematics Configurations
      3. 7.7.3 Terminations
      4. 7.7.4 Peripheral (Sub System) Clock Outputs
      5. 7.7.5 General Debug
        1. 7.7.5.1 Clock Output for Board Bring-Up, Test or Debug
        2. 7.7.5.2 Additional Information
  11. 8 Layout Notes (to be Added on the Schematic)
  12. 9 Board Design Simulation
  13. 10Additional References
  14. 11Summary
  15. 12References
    1. 12.1 AM64x
    2. 12.2 AM243x
    3. 12.3 Common
  16.   A Terminology
  17.   Revision History

6.1.5.1 Processor Boot Mode Inputs Isolation Buffers Use Case and Optimization

In the EVM, the boot mode pins Bootmode [15:00] are asserted through two buffers (isolation buffers). The buffers ensure that SYSBOOT pulls (boot mode configured using resistors) are controlling the level of the signals when the boot mode signals are being latched (around the PORz_OUT rising edge) by the processor. Since boot mode signals are often used for other functions after processor power-up and are connected to other devices, boot mode configuration resistors need to be isolated from other connected peripherals so that those peripherals do not conflict with the intended boot mode configuration (signal levels).

The buffers are enabled only when PORz_OUT is driven low by the processor. After PORz_OUT goes high, the buffer outputs are Hi-Z so the signals are not pulled up or down by the boot mode resistors.

For optimizing the design and BOM, these buffers can be optimized or removed depending on the use case. The boot mode pull resistor values can be selected so that they do not affect the operation of attach devices.