SPRUIY9B May   2021  – October 2023

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Key Features
  5. 2EVM Revisions and Assembly Variants
  6. 3Important Usage Notes
  7. 4System Description
    1. 4.1 Key Features
    2. 4.2 Functional Block Diagram
    3. 4.3 Power-On/Off Procedures
      1. 4.3.1 Power-On Procedure
      2. 4.3.2 Power-Off Procedure
    4. 4.4 Peripheral and Major Component Description
      1. 4.4.1  Clocking
        1. 4.4.1.1 Ethernet PHY Clock
        2. 4.4.1.2 AM64x SoC Clock
      2. 4.4.2  Reset
      3. 4.4.3  Power
        1. 4.4.3.1 Power Input
        2. 4.4.3.2 USB Type-C Interface for Power Input
        3. 4.4.3.3 Power Fault Indication
        4. 4.4.3.4 Power Supply
        5. 4.4.3.5 Power Sequencing
        6. 4.4.3.6 Power Supply
      4. 4.4.4  Configuration
        1. 4.4.4.1 Boot Modes
      5. 4.4.5  JTAG
      6. 4.4.6  Test Automation
      7. 4.4.7  UART Interface
      8. 4.4.8  Memory Interfaces
        1. 4.4.8.1 LPDDR4 Interface
        2. 4.4.8.2 MMC Interface
          1. 4.4.8.2.1 Micro SD Interface
          2. 4.4.8.2.2 WiLink Interface
          3. 4.4.8.2.3 OSPI Interface
          4. 4.4.8.2.4 Board ID EEPROM Interface
      9. 4.4.9  Ethernet Interface
        1. 4.4.9.1 DP83867 PHY Default Configuration
        2. 4.4.9.2 DP83867 – Power, Clock, Reset, Interrupt and LEDs
        3. 4.4.9.3 Industrial Application LEDs
      10. 4.4.10 USB 3.0 Interface
      11. 4.4.11 PRU Connector
      12. 4.4.12 User Expansion Connector
      13. 4.4.13 MCU Connector
      14. 4.4.14 Interrupt
      15. 4.4.15 I2C Interface
      16. 4.4.16 IO Expander (GPIOs)
  8. 5Known Issues
    1. 5.1 Issue 1: LP8733x Max output Capacitance Spec Exceeded on LDO0 and LDO1
    2. 5.2 Issue 2: LP8733x Output Voltage of 0.9V Exceeds AM64x VDDR_CORE max Voltage Spec of 0.895 V
    3. 5.3 Issue 3 - SDIO Devices on MMC0 Require Careful Trace Lengths to Meet Interface Timing Requirements
    4. 5.4 Issue 4 - LPDDR4 Data Rate Limitation in Stressful Conditions
    5. 5.5 Issue 5 - Junk Character
    6. 5.6 Issue 6 - Test Power Down Signal Floating
    7. 5.7 Issue 7 - uSD Boot Not Working
  9. 6Regulatory Compliance
  10. 7Revision History

4.4.16 IO Expander (GPIOs)

The I/O Expander used in the AM64x SoC is a 8-Bit, I2C based I/O Expander, which is used for daughter card plug-in detection and also to generate resets and enable signals to various peripheral devices connected. The I2C1 bus of the AM64X SoC is used to interface to the I/O Expander and the address of the I/O Expander is 0X70. Below is the list of signals being controlled by the IO expander.

Table 4-23 IO Expander Pin Details
Pin No. Signal Direction Device
P0 GPIO_CPSW2_RST Output CPSW PHY-2 ETHERNET
P1 GPIO_CPSW1_RST Output CPSW PHY-1 ETHERNET
P2 PRU_DETECT Input PRU Connector Detection
P3 MMC1_SD_EN Output SD Card power switch enable
P4 VPP_LDO_EN Output SoC VPP voltage generation
P5 RPI_PS_3V3_En Output User expansion connector: 3V3 supply Power Switch Enable
P6 RPI_PS_5V0_En Output User Expansion Connector: 5V0 supply power switch enable
P7 RPI_HAT_DETECT Input User expansion connector: hardware add-on board detection