SPRACL9 May   2019 66AK2E05 , 66AK2H06 , 66AK2H12 , 66AK2H14 , AM5K2E02 , AM5K2E04 , TMS320C6652 , TMS320C6654 , TMS320C6655 , TMS320C6657 , TMS320C6670 , TMS320C6671 , TMS320C6672 , TMS320C6674 , TMS320C6678

 

  1.   KeyStone Multicore Device Family Schematic Checklist
    1.     Trademarks
    2. 1 Introduction
    3. 2 Hardware Design Guide
    4. 3 Device Comparison
      1. 3.1 KeyStone II Devices
      2. 3.2 KeyStone I Devices
    5. 4 Power Management Solutions
    6. 5 Recommendations Specific to all KeyStone Devices
      1. 5.1 EVM vs Data Sheet
      2. 5.2 Critical Connections
        1. 5.2.1 Power
        2. 5.2.2 Clocking
        3. 5.2.3 LJCB Differential Clock Inputs
        4. 5.2.4 Clock Termination
        5. 5.2.5 Unused Clock Inputs
        6. 5.2.6 Reset
        7. 5.2.7 GPIO/Boot Configuration
        8. 5.2.8 JTAG and EMU
    7. 6 Peripherals
      1. 6.1 DDR3 Interface
        1. 6.1.1  EMIF16
        2. 6.1.2  SerDes
        3. 6.1.3  HyperLink
        4. 6.1.4  PCIe
        5. 6.1.5  SRIO
        6. 6.1.6  SGMII
        7. 6.1.7  MDIO
        8. 6.1.8  TSIP
        9. 6.1.9  I2C
        10. 6.1.10 SPI
        11. 6.1.11 UART
        12. 6.1.12 I/O Buffers and Termination
    8. 7 Recommendations Specific to KeyStone II Devices
      1. 7.1 Peripherals
        1. 7.1.1 USB
    9. 8 General Recommendations
      1. 8.1 Before You Begin
        1. 8.1.1 Documentation
        2. 8.1.2 Pinout
    10. 9 References

5.2.7 GPIO/Boot Configuration

  • The design must support the dual role of these pins. The pins need to return to the boot configuration levels whenever the boot configuration is latched. This is indicated by RESETSTATz low on most devices.
  • Boot configuration can rely on the internal pull-up or pull-down resistors for most devices. However, if any track, even a test pad, is added to a pin, an external resistor must be added to maintain the rated noise immunity.
  • Sometimes boot configuration inputs are multiplexed with other interfaces like timers, which are often overlooked. These pins must also revert to their boot-configuration level whenever it will be latched.
  • Internal resistors can be as low as 8K Ω. This must be considered when connecting an external resistor to oppose it. Additionally, when multiple pins are bussed together, the combined leakage current of the internal resistors must be considered.