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

2.6 General DDR Guidelines

These guidelines are applicable for all DDR designs:

  • It is very important to follow the DDR routing guidelines for your DDR type in the AM335x data sheet. These guidelines are very important to ensure a proper DDR design.
  • Ensure resistor for DDR_VTP is a high precision resistor as specified in the data sheet. A 49.9 Ω 1% resistor is less expensive than a 50 Ω 2% resistor and can be used for the DDR_VTP pin for cost sensitive designs.
  • When using a resistor divider for DDR_VREF, ensure resistors are high precision resistors as specified in the device-specific data sheet
  • Allow for adequate decoupling capacitors on the DDR power rails both at the AM335x as well as the DDR SDRAM device(s)