SPRAD67D September   2024  – October 2025 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
    1. 1.1 Before Getting Started With the Custom Board Design
    2. 1.2 Processor-Specific SDK
    3. 1.3 Peripheral Circuit Implementation - Compatibility Between Processor Families
    4. 1.4 Selection of Required Processor OPN (Orderable Part Number)
      1. 1.4.1 Availability of Tightly Coupled Memory (TCM)
      2. 1.4.2 Processor Support for Secure Boot and Functional Safety
    5. 1.5 Technical Documentation
      1. 1.5.1 Updated EVM or SK Schematic With Design, Review and Cad Notes Added
      2. 1.5.2 Collaterals on TI.com, Processor Product Page
      3. 1.5.3 Schematic Design Guidelines and Schematic Review Checklist - Processor Family Specific User's Guide
      4. 1.5.4 Updates to Hardware Design Considerations User's Guide
      5. 1.5.5 Processor and Peripherals Related FAQs to Support Custom Board Designs
    6. 1.6 Custom Board Design Documentation
    7. 1.7 Processor and Processor Peripherals Design Related Queries During Custom Board Design
  5. 2 Custom Board Design Block Diagram
    1. 2.1 Developing the Custom Board Design Block Diagram
    2. 2.2 Configuring the Boot Mode
    3. 2.3 Configuring the Processor Pins Functionality (PinMux Configuration)
  6. 3 Power Supply
    1. 3.1 Power Supply Architecture
      1. 3.1.1 Integrated Power Architecture
      2. 3.1.2 Discrete Power Architecture
    2. 3.2 Processor Supply (Power) Rails (Operating Voltage)
      1. 3.2.1 Core Power Supply
      2. 3.2.2 Peripherals Power Supply
      3. 3.2.3 Dual-Voltage IO Supply for IO Group (Processor) Power Supply
      4. 3.2.4 Integrated LDO for SD Card Interface (Dynamic Voltage Switching Dual-Voltage Power Supply)
      5. 3.2.5 VPP (eFuse ROM Programming) Power Supply
      6. 3.2.6 Internal LDOs for IO Supply for IO Groups (Processor)
    3. 3.3 Power Supply Filtering
    4. 3.4 Power Supply Decoupling and Bulk Capacitors
      1. 3.4.1 Note on PDN Target Impedance
    5. 3.5 Power Supply Sequencing
    6. 3.6 Power Supply Diagnostics (Using Processor Supported External Input Voltage Monitors)
    7. 3.7 Power Supply Diagnostics (Monitoring Using External Monitoring Circuit (Devices))
    8. 3.8 Custom Board Current Requirements Estimation and Supply Sizing
  7. 4 Processor Clock (Input and Output)
    1. 4.1 Processor Clocking (External Crystal or External Oscillator)
      1. 4.1.1 Unused Clock Input
      2. 4.1.2 MCU_OSC0 Crystal Selection
      3. 4.1.3 LVCMOS Compatible Digital Clock Input Source
    2. 4.2 Processor Clock Output
      1. 4.2.1 Observation Clock Outputs
    3. 4.3 Clock Tree Tool
  8. 5 JTAG (Joint Test Action Group)
    1. 5.1 JTAG / Emulation
      1. 5.1.1 Configuration of JTAG / Emulation
        1. 5.1.1.1 BSDL File
      2. 5.1.2 Implementation of JTAG / Emulation
      3. 5.1.3 Connection Recommendations for JTAG Interface Signals
      4. 5.1.4 Debug Boot Modes and Boundary Scan Compliance
  9. 6 Configuration (Processor) and Initialization (Processor and Device)
    1. 6.1 Processor Reset
    2. 6.2 Latching of Processor Boot Mode Configuration Inputs
    3. 6.3 Resetting of the Attached Devices
    4. 6.4 Watchdog Timer
  10. 7 Processor - Peripherals Connection
    1. 7.1  Supported Processor Cores and MCU Cores
    2. 7.2  Selecting Peripherals Across Domains
    3. 7.3  Memory Controller (DDRSS)
      1. 7.3.1 Processor DDR Subsystem and Device Register Configuration
      2. 7.3.2 Calibration Resistor Connection for DDRSS
      3. 7.3.3 Attached Memory Device ZQ and Reset_N (Memory Device Reset) Connection
    4. 7.4  Media and Data Storage Interfaces (MMC0, MMC1, OSPI0/QSPI0 and GPMC0)
    5. 7.5  Ethernet Interface
      1. 7.5.1 Common Platform Ethernet Switch 3-port Gigabit (CPSW3G0)
      2. 7.5.2 Programmable Real-Time Unit and Industrial Communication Subsystem - Gigabit (PRU_ICSSG)
    6. 7.6  Universal Serial Bus (USB) Subsystem
    7. 7.7  Peripheral Component Interconnect Express (PCIe) Subsystem
    8. 7.8  General Connectivity Peripherals
      1. 7.8.1 Inter-Integrated Circuit (I2C) Interface
    9. 7.9  Analog-to-Digital Converter (ADC0)
      1. 7.9.1 Change Summary of AM64x, AM243x SR2.0 ADC Errata (FYI only)
    10. 7.10 Connection of Processor Power Supply Pins, IOs and Peripherals When not Used
      1. 7.10.1 External Interrupt (EXTINTn)
      2. 7.10.2 RSVD Reserved Pins (Signals)
    11. 7.11 EVM or SK Specific Circuit Implementation (Reuse)
  11. 8 Interfacing of Processor IOs (LVCMOS or SDIO or Open-Drain, Fail-Safe Type IO Buffers) and Performing Simulations
    1. 8.1 IBIS Model
    2. 8.2 IBIS-AMI Model
  12. 9 Processor Current Draw and Thermal Analysis
    1. 9.1 Power Estimation
      1. 9.1.1 AM64x
      2. 9.1.2 AM243x
    2. 9.2 Maximum Current Rating for Different Supply Rails
      1. 9.2.1 AM64x
      2. 9.2.2 AM243x
    3. 9.3 Supported Device Power States
    4. 9.4 Thermal Design Guidelines
      1. 9.4.1 Thermal Model
      2. 9.4.2 Voltage Thermal Management Module (VTM)
  13. 10Schematic:- Capture, Entry and Review
    1. 10.1 Custom Board Design Passive Components and Values Selection
    2. 10.2 Custom Board Design Electronic Computer Aided Design (ECAD) Tools Considerations
    3. 10.3 Custom Board Design Schematic Capture
    4. 10.4 Custom Board Design Schematic Review
  14. 11Floor Planning, Layout, Routing Guidelines, Board Layers, and Simulation
    1. 11.1 Escape Routing for PCB Design
      1. 11.1.1 AM64x
      2. 11.1.2 AM243x
    2. 11.2 DDR Design and Layout Guidelines
    3. 11.3 High-Speed Differential Signal Routing Guidelines
    4. 11.4 Processor-Specific EVM or SK Board Layout
    5. 11.5 Custom Board Layer Count and Layer Stack-up
      1. 11.5.1 Simulation Recommendations
    6. 11.6 DDR-MARGIN-FW
    7. 11.7 Reference for Steps to be Followed for Running Board Simulation
    8. 11.8 Software Development Training (Academy) for Processors
  15. 12Custom Board Assembly and Testing
    1. 12.1 Custom Board Bring-up Tips and Debug Guidelines
  16. 13Processor (Device) Handling and Assembly
    1. 13.1 Processor (Device) Soldering Recommendations
      1. 13.1.1 Additional References
  17. 14References
    1. 14.1 AM64x
    2. 14.2 AM243x
    3. 14.3 Common
  18. 15Terminology
  19. 16Revision History

3.2.4 Integrated LDO for SD Card Interface (Dynamic Voltage Switching Dual-Voltage Power Supply)

The processor families support an integrated LDO (SDIO_LDO) to power the SDIO interface IO supply for IO group and SD card interface pullups, capable of dynamically switching between 3.3V and 1.8V voltage. The recommendation is to connect the recommended output capacitor close to the LDO output pin (CAP_VDDSHV_MMC1). For information on recommended, capacitor value and connection, refer to the Power Supply sub-section in the Signal Descriptions section of the device-specific data sheet.

V1P8_SIGNAL_ENA bit is used to switch the LDO output level used for controlling the SD card interface IO levels (signaling). The recommendation is to connect the supply connected to the SD card as input to SDIO_LDO. The output of the internal LDO can be connected to the processor IO supply for IO group used for SD card interface (VDDSHV5 for UHS-I SD card support).

For connecting the LDO pins (SDIO_LDO and CAP_VDDSHV_MMC1) when not used, see the Pin Connectivity Requirements section of the device-specific data sheet.

For more information, see the Integrated Low-dropout Regulator (LDO) section in the Power chapter of the device-specific TRM.