SPRABN2A March   2019  – December 2019 AM3352 , AM3354 , AM3356 , AM3357 , AM3358 , AM3358-EP , AM3359

 

  1.   AM335x Schematic Checklist
    1.     Trademarks
    2. 1 Introduction
    3. 2 Recommendations Specific to AM335x
      1. 2.1  Unused Signals
      2. 2.2  SYSBOOT Configuration and Required Termination
      3. 2.3  System Issues
        1. 2.3.1 Pinmux
        2. 2.3.2 Pullups
        3. 2.3.3 General Debug
        4. 2.3.4 Warm Reset
        5. 2.3.5 Peripheral Clocking
      4. 2.4  Low-Power Considerations
      5. 2.5  Clocking
      6. 2.6  General DDR Guidelines
        1. 2.6.1 DDR2
        2. 2.6.2 DDR3
      7. 2.7  MultiMedia Card/ (MMC)
      8. 2.8  Inter-Integrated Circuit (I2C)
      9. 2.9  LCD
      10. 2.10 Power
      11. 2.11 Touchscreen
        1. 2.11.1 If ADC/Touchscreen is not Used
      12. 2.12 USB
        1. 2.12.1 If USB0 or USB1 is not Used
      13. 2.13 External Interrupt (EXTINTn)
      14. 2.14 Ethernet
    4. 3 References
  2.   Revision History

2.1 Unused Signals

Signals on interfaces that are unused can typically be left as no connect. Many of the IOs have a Pad Control Register that provides control over the input capabilities of the I/O (RXACTIVE field in each conf_<module>_<pin> register). For more details, see the Control Module chapter of the AM335x and AMIC110 Sitara™ Processors Technical Reference Manual. In initialization, software should disable the I/Os that are no connects (RXACTIVE=0) as soon as possible. This RXACTIVE field defaults to "input active" for most signals, which means there is a potential for some leakage during powerup of the chip if the input floats to a mid-supply level before the software can initialize the I/O. This should only be a concern if you are attempting to power up the design with a minimum power consumption. Most designs should be able to tolerate this small amount of leakage in each floating I/O until the software has a change to disable it. After disabling the I/O, no leakage will occur.