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

4.16 IO Expander (GPIOs)

The I/O Expander used in the AM64x SoC is a 8-Bit I2C based I/O Expander used for daughter card plug-in detection and also to generate resets and enable signals to various peripheral devices connected to it. 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. Table 4-23 lists the signals controlled by the IO expander.

Table 4-23 IO Expander Pin-outs
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