SPRAD85A March   2023  – September 2024 AM62A3 , AM62A3-Q1 , AM62A7 , AM62A7-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
    1. 1.1 Before Getting Started With the Custom Board Design
    2. 1.2 Processor Selection
    3. 1.3 Technical Documentation
      1. 1.3.1 Updated SK Schematics With Design, Review and Cad Notes Added
      2. 1.3.2 FAQs to Support Custom Board Design
    4. 1.4 Design Documentation
  5. 2 Block Diagram
    1. 2.1 Constructing the Block Diagram
    2. 2.2 Configuring the Boot Mode
    3. 2.3 Confirming PinMux (PinMux Configuration)
  6. 3 Power Supply
    1. 3.1 Power Supply Architecture
      1. 3.1.1 Integrated Power
      2. 3.1.2 Discrete Power
    2. 3.2 Power (Supply) Rails
      1. 3.2.1 Core Supply
      2. 3.2.2 Peripheral Power Supply
      3. 3.2.3 Dynamic Switching Dual-Voltage IO Supply LDO
      4. 3.2.4 Internal LDOs for IO Groups (Processor)
      5. 3.2.5 Dual-Voltage IOs (for Processor IO Groups)
      6. 3.2.6 VPP (eFuse ROM programming) Supply
    3. 3.3 Determining Board Power Requirements
    4. 3.4 Power Supply Filters
    5. 3.5 Power Supply Decoupling and Bulk Capacitors
      1. 3.5.1 Note on PDN Target Impedance
    6. 3.6 Power Supply Sequencing
    7. 3.7 Supply Diagnostics
    8. 3.8 Power Supply Monitoring
  7. 4 Processor Clocking
    1. 4.1 Processor External Clock Source
      1. 4.1.1 Unused WKUP_LFOSC0
      2. 4.1.2 LVCMOS Digital Clock Source
      3. 4.1.3 Crystal Selection
    2. 4.2 Processor Clock Outputs
  8. 5 JTAG (Joint Test Action Group)
    1. 5.1 JTAG / Emulation
      1. 5.1.1 Configuration of JTAG / Emulation
      2. 5.1.2 Implementation of JTAG / Emulation
      3. 5.1.3 Connection of JTAG Interface Signals
  9. 6 Configuration (Processor) and Initialization (Processor and Device)
    1. 6.1 Processor Reset
    2. 6.2 Latching of Boot Mode Configuration
    3. 6.3 Resetting the Attached Devices
    4. 6.4 Watchdog Timer
  10. 7 Processor Peripherals
    1. 7.1  Selecting Peripherals Across Domains
    2. 7.2  Memory (DDRSS)
      1. 7.2.1 Processor DDR Subsystem and Device Register Configuration
      2. 7.2.2 Calibration Resistor Connection for DDRSS
      3. 7.2.3 Attached Memory Device ZQ and Reset_N Connection
    3. 7.3  Media and Data Storage Interfaces
    4. 7.4  Common Platform Ethernet Switch 3-port Gigabit (CPSW3G - for Ethernet Interface)
    5. 7.5  Programmable Real-Time Unit Subsystem (PRUSS)
    6. 7.6  Universal Serial Bus (USB) Subsystem
    7. 7.7  General Connectivity Peripherals
    8. 7.8  Display Subsystem (DSS)
    9. 7.9  Camera Subsystem (CSI)
    10. 7.10 Connection of Processor Power Supply Pins, Unused Peripherals and IOs
      1. 7.10.1 External Interrupt (EXTINTn)
      2. 7.10.2 Reserved (RSVD) Pins
  11. 8 Interfacing of Processor IOs ( LVCMOS or Open-Drain or Fail-Safe Type IO Buffers) and Simulations
  12. 9 Processor Current Rating and Thermal Analysis
    1. 9.1 Power Estimation
    2. 9.2 Maximum Current Rating for Different Supply Rails
    3. 9.3 Power Modes
    4. 9.4 Thermal Design Guidelines
      1. 9.4.1 VTM (Voltage Thermal Management Module)
  13. 10Schematics:- Design, Capture, Entry and Review
    1. 10.1 Selection of Components and Values
    2. 10.2 Schematic Design and Capture
    3. 10.3 Schematics Review
  14. 11Floor Planning, Layout, Routing Guidelines, Board Layers and Simulation
    1. 11.1 Escape Routing for PCB Design
    2. 11.2 LPDDR4 Design and Layout Guidelines
    3. 11.3 High-Speed Differential Signals Routing Guidelines
    4. 11.4 Board Layer Count and Stack-up
      1. 11.4.1 Simulation Recommendations
    5. 11.5 Reference for Steps to be Followed for Running Simulation
  15. 12Custom Board Assembly and Testing
    1. 12.1 Guidelines and Board Bring-up Tips
  16. 13Device Handling and Assembly
    1. 13.1 Soldering Recommendations
      1. 13.1.1 Additional References
  17. 14References
    1. 14.1 Processor Specific
    2. 14.2 Common
  18. 15Terminology
  19. 16Revision History

7.2 Memory (DDRSS)

DDR Subsystem currently supports LPDDR4 memory interface. Refer Memory Subsystem, DDR Subsystem (DDRSS) section in the Features chapter of device-specific data sheet for data bus width, inline ECC support, speed and max addressable range selection.

The allowed memory configurations are 1 X 32-bit or 1 X 16-bit.

1 X 8-bit memory configuration is not a valid configuration.

Based on the application requirements, same memory (LPDDR4) device can be used with the AM625 / AM623 / AM625-Q1 / AM620-Q1 , AM62A7 / AM62A3 and AM62P / AM62P-Q1 processors due to the availability of 1 X 16-bit configuration.

When the AM62A7 / AM62A3 processors are configured for 16-bit configuration, follow the DQS2..3 and other unused signal connection recommendations shown in the 16-Bit, Single Rank LPDDR4 Implementation example of the AM62Ax / AM62Px LPDDR4 Board Design and Layout Guidelines.

Refer Pin Connectivity Requirements section of the device-specific data sheet for connecting the DDRSS signals when not used.

For more details, refer the DDR Subsystem (DDRSS) section in the Memory Controllers chapter of the device-specific TRM.

For more information on DDR4 / LPDDR4 memory interface, see the [FAQ] AM625 / AM623 / AM62A / AM62P Design Recommendations / Commonly Observed Errors during Custom board hardware design – DDR4 / LPDDR4 MEMORY Interface.