SPRUJ64 September   2022

 

  1.   Abstract
  2.   Trademarks
  3. 1Key Features
  4. 2AM64x SKEVM Overview
    1. 2.1 Board Version Identification
  5. 3Functional Block Diagram
  6. 4System Description
    1. 4.1  Clocking
      1. 4.1.1 Ethernet PHY Clock
      2. 4.1.2 AM64x SoC Clock
    2. 4.2  Reset
    3. 4.3  Power Requirements
      1. 4.3.1 Power Input
      2. 4.3.2 USB Type-C Interface for Power Input
      3. 4.3.3 Power Fault Indication
      4. 4.3.4 Power Supply
      5. 4.3.5 Power Sequencing
      6. 4.3.6 SOC Power
    4. 4.4  Configuration
      1. 4.4.1 Boot Modes
    5. 4.5  JTAG
    6. 4.6  Test Automation
    7. 4.7  UART Interface
    8. 4.8  Memory Interfaces
      1. 4.8.1 LPDDR4 Interface
      2. 4.8.2 MMC Interface
        1. 4.8.2.1 Micro SD Interface
        2. 4.8.2.2 WiLink Interface
        3. 4.8.2.3 OSPI Interface
        4. 4.8.2.4 Board ID EEPROM Interface
    9. 4.9  Ethernet Interface
      1. 4.9.1 DP83867 PHY Default Configuration
      2. 4.9.2 DP83867 – Power, Clock, Reset, Interrupt, and LEDs
      3. 4.9.3 Industrial Application LEDs for Indication
    10. 4.10 USB 3.0 Interface
    11. 4.11 PRU Connector
    12. 4.12 User Expansion Connector
    13. 4.13 MCU Connector
    14. 4.14 Interrupt
    15. 4.15 I2C Interface
    16. 4.16 IO Expander (GPIOs)
  7. 5Known Issues and Modifications
    1. 5.1 Issue 1 - Silkscreen Missprint on Initial Board Batch
  8. 6Revision History

4.3.1 Power Input

The SKEVM receives 5-V input from a USB Type-C connector. The following sections describe the power distribution network topology that supply the SKEVM board, supporting components and reference voltages.

The AM64x SKEVM board includes a power solution based on PMIC and a few discrete regulators. The initial stage of the power supply is 5 V from a Type-C USB connector with part No 2012670005 from Molex, which supports a 3A current rating and necessary protection circuits for over current and voltage surge. The 5-V input (VUSB_MAIN) from the USB Connector is used to generate 3.3 V (VCC3V3SYS_EXT) with the help of switching regulator (part No. LM61460AASQRJRRQ1), which is the input supply to the PMIC section. PMIC generates the necessary voltages required for the SKEVM.

A Toggle switch (with part number AS11AP) is provided to initiate the power on and power down sequence of the Board. This switch connects TPS6522053_EN enable signal to ground when switch is in OFF position and enables PMIC TPS6522053RHBR when the switch is in ON position, thereby initiating the Power – Up Sequence. A low on enable pin of the TPS6522053RHBR PMIC, by sliding the switch to OFF position, initiates the Power-down sequence.

Additionally, TEST_POWERDOWN from the test automation header is also connected to the enable pin of TPS6522053RHBR PMIC to control on/off of the EVM through the test automation board. The test automation connector requires 3.3-V supply, which is provided from power mux (part No: TPS2121RUXT). The inputs to the power mux are 3V3 from two different sources. First 3V3 supply is generated from 5V (XDS_USB_VBUS) using an LDO (Part No: TPS79601DRBR). This will be generated if the Micro B cable is connected to J12. Second 3V3 input is generated from 5V (VUSB_MAIN) using a switching Buck regulator (part No: TPS62177DQCR). This is an Always ON Regulator and supplies the necessary power if the USB Type C Cable is plugged in. When Both Type C cable and Micro B cable at J12 are connected, the mux priority is set to its first input supply (VCC3V3_XDS). If USB is not connected to the J12, the mux output is from VCC3V3_TA, which is an always ON power supply.