DSR eMMC

[christiansielaf]

Hi all,

how we can adjust the driver strength of the I/O's for the eMMC (eSDHC) controller? We are working on a coustomer LS1021A design, with really short traces between eMMC and processor. We could observ overshoot at the CMD line which are out of operation range.

We realy appreciate your response.

Best regards and thank you in advance,

Christian

[alexander_yakov · Accepted solution]

The fact that you are observing overshot means output driver strength needs to be reduced - output driver impedance is to low and needs to be increased. 

The typical way to increase output driver impedance is to place series resistor at the near (source) end of trace.

Output driving strength on eSDHC signals can not be changed by software.

Have a great day,
Alexander

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