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AM3352: DDR write leveling parameters

Tony Tang
Mastermind 28032 points
Part Number: AM3352

As DDR3 device usually EOL, customer needs to prepare backup stock of DDR3 device. but different DDR3 device got different writing leveling result. 

So customer asks:

#1. If only use signal 16bit DDR3 device, doesn't it need to do software leveling?

#2. What is mean of below parameters, what is the relation between those parameter to DDR timing? if there are small different between different DDR3 vendor, can they use the same set of parameter?

#define  DATA_PHY_RD_DQS_SLAVE_RATIO    0x3A
#define  DATA_PHY_FIFO_WE_SLAVE_RATIO   0x11B //RD DQS GATE
#define  DATA_PHY_WR_DQS_SLAVE_RATIO    0xA8
#define  DATA_PHY_WR_DATA_SLAVE_RATIO   0xE1  //WRITE DATA
  • 0
    TI__Guru* 80020 points

    Tony, if they are replacing the 16bit DDR3 device with one that has the same timings, and the board layout is not changing, then they should be able to use the same DDR configuration. 

    Software leveling is not necessary when using just a single DDR3 device.  The parameters you cite represent the delay line values for the address and data macros inside the DDR controller/PHY.  With only a single DDR3 device, these are calculations based on the trace length inputs in the DDR EMIF tool spreadsheet, and leveling is not required.

    Regards,

    James

     

  • 0 in reply to JJD
    TI__Mastermind 28032 points

    James,

    Thanks for confirmation. From experience, if did not do software leveling will introducing board stability risk. I am wondering if you separate  RatioSeed_AM335x_boards.xls and do software leveling with its seeds.

    #1. Single 16bit DDR doesn't need software leveling. Does it still need to use RatioSeed_AM335x_boards.xls to get seed values and update to DDR configuration？

    Seed values used in CCS code
    DATAx_PHY_RD DQS_SLAVE_RATIO
    DATAx_PHY_FIFO_WE_SLAVE_RATIO
    DATAx_PHY_WR DQS_SLAVE_RATIO
    Register value
    CMDx_PHY_CTRL_SLAVE_RATIO

    #2. If #1 is Yes. how to get DATA_PHY_WR_DATA_SLAVE_RATIO value, it is not in RatioSeed_AM335x_boards.xls.

  • 0 in reply to JJD
    TI__Mastermind 28032 points

    James,

    Would you please help to confirm? Thanks.

  • 0 in reply to Tony Tang
    TI__Guru* 80020 points

    Yes, you still need to use the results from the spreadsheet.  Please note that we have recently updated the EMIF tools for AM335x, please see: http://www.ti.com/lit/pdf/sprack4

    DATA_PHY_WR_DATA_SLAVE_RATIO value is based on DATA_PHY_WR_DQS_SLAVE_RATIO:

    WR_DATA_SLAVE_RATIO = WR_DQS_SLAVE_RATIO + 0x40

    Regards,

    James