AnsweredAssumed Answered

iMX8 uSDHC SD3.0 tuning

Question asked by Miles Wang on Aug 30, 2018
Latest reply on Sep 5, 2018 by Yuri Muhin

Dear sir,

I'm confused about the SD3.0 tuning.

In iMX8RM, there is a register "uSDHCx_TUNING_CTRL", bit 24 - STD_TUNING_EN. If the bit is set, standard tuning circuit and procedure enable. I want to know what is "standard tuning", how to do standard tuning. There should be "non-standard tuning", how to do "non-standard tuning"?

In  register "uSDHCx_MIX_CTRL", bit 24 - AUTO_TUNE_EN; bit 22 - EXE_TUNE. How to do auto-tune? and how to do manual-tune? Do auto-tune have relation with "standard tuning" or "non-standard tuning".

By my understanding, there should be 4 possibility:

1. standard tuning by auto-tune;

2. standard tuning by manual-tune;

3. non-standard tuning by auto-tune;

4. non-standard tuning by manual-tune.

Is it correct? I really don't know how to do tuning. I need a note to describe how to do it.