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DDR3 software leveling

Michi Yama
Guru 10030 points

Other Parts Discussed in Thread: AM3874

Hi,

I have some questions regarding DDR3 software leveling.

According to the AM3874 datasheet 7.2.8 DDR3 Software Write/Read leveling, "When software leveling is used there is no need to enable the leveling feature of the external DDR3 SDRAM.

However, JEDEC specifies the leveling feature of DDR3 memory as you know. I think TI's software leveling is special case. How do you think about this?

I suspect that AM3874 does not have a feature for enabling DDR3 leveling feature? Maybe, AM3874 does not have CLK-DQS leveling feature? But this is very general.

If AM3874 can not use the leveling feature of DDR3 memory, does not  execute CLK-DQS leveling,  and software leveling is only way for AM3874,  whose memory manufacturer is authorised this way?

I can not explain TI's software leveling solution. As I wrote the above, it is not general way.

Please advise me.

Best regards,

Michi   

 

  • 0
    TI__Guru**** 170625 points

    Michi,

    Michi Yama said:

    According to the AM3874 datasheet 7.2.8 DDR3 Software Write/Read leveling, "When software leveling is used there is no need to enable the leveling feature of the external DDR3 SDRAM.

    However, JEDEC specifies the leveling feature of DDR3 memory as you know. I think TI's software leveling is special case. How do you think about this?

    "leveling of the external DDR3" is the same as "hardware leveling" and "auto-leveling". And hardware leveling is not supported on AM387x device per silicon bug/errata. See section 2.1.3. Thus only software leveling is available.

    BR
    Pavel