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DRA71XEVM: DDR &EMMCproblem

David chen
Expert 1200 points
Part Number: DRA71XEVM

hi  Team:

1. in the DRA71XEVM,The DDR use 4*8bit DDR3,if I use 2*16bit  DDR3 or  1*32bit  DDR3,Which is better performance?

2. if I use 2*16bit  DDR3,I can use Choose any one  for use?

3. The EMMC is Standard  for V4.5,it support for  Standard V5.0.V5.1 V4.4?

  • 0
    TI__Mastermind 46632 points

    1.  Any of the stated topologies can support DDR-1333 data rate as long as the Data Manual layout guidelines are followed carefully.  It may be slightly easier to implement with 2x16 (two loads on address/command) compared to 4x8 (4 loads on address/command).  My understanding is that x32 aren't readily available in the market - but this would need to be confirmed by memory vendors.

    2. You should choose a memory that is JEDEC compatible and has a speed grade DDR3-1333 or faster.

    3. Yes, the eMMC interface is compatible with Standard 4.5 or newer memories.

    Thanks,
    Kyle

  • 0 in reply to kcastille
    Expert 1200 points

    hi team:if only  use one of 16-bit bandwidth ddr3L will limit the best  performance of processor compared to 32-bit？

  • 0 in reply to David chen
    TI__Mastermind 46632 points

    David,

    If you use 1x16 bit DDR3 component you will get 1/2 of the peak bandwidth compared to populating the full 32-b data bus. 

    You can run experiments in software to determine if that will impact the overall performance of your application.

    First, you should build a PCB using 2x16 bit memories (32-b wide).  In software, you can enable the bus to use the full 32-b or can configure to use only 1/2 width (16-b).  By running your application with both configurations, you can decide if the full DDR bandwidth is required for your application.

    Regards,

    Kyle