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

3.2.5 Dual-Voltage IOs (for Processor IO Groups)

The processor family supports nine Dual-voltage IO groups (VDDSHVx [x=0..6], VDDSHV_MCU and VDDSHV_CANUART), where each IO group provides power to a predefined set of IOs. Each IO group can be individually configured for 3.3V or 1.8V. This supply powers all the predetermined IOs in the IO supply group. All IOs (attached devices) connected to these IO groups must be powered from the same power source that is being used to power the respective processor Dual-voltage IO groups (VDDSHVx supply rail).

Most of the processor IOs are not fail-safe. For information on available fail-safe IOs, see the device-specific data sheet. It is recommended to power IO supply of attached devices from the same power source as the respective processor Dual-voltage IO groups (VDDSHVx supply rail) to ensure the system or board never applies potential to an IO that is not powered. This is needed to protect the IOs of processor and attached devices.

For more information, see the [FAQ] AM625/AM623 Custom board hardware design – Power sequencing between SOC (Processor) and the Attached devices (Fail-safe). This is a generic FAQ and can also be used for AM62A7 / AM62A3 family of processors.

Available IO groups information is summarized below:

VDDSHV0 – Dual-voltage IO supply for Main reset and General interface IO group

VDDSHV1 – Dual-voltage IO supply for OSPI0 IO group

VDDSHV2 – Dual-voltage IO supply for RGMII1..2 IO group

VDDSHV3 – Dual-voltage IO supply for GPMC0 IO group

VDDSHV4 – Dual-voltage IO supply for MMC0 IO group

VDDSHV5 – Dual-voltage IO supply for MMC1 IO group

VDDSHV6 – Dual-voltage IO supply for MMC2 IO group

VDDSHV_MCU – Dual-voltage IO supply for WKUP_MCU IO group

VDDSHV_CANUART – Dual-voltage IO supply for CANUART IO group

Note:

It is recommended to connect VDDSHV_CANUART to an always on power sources when Partial IO (Low-power) mode is used.