Slow CD clock

Dear all:
I have co-design a carrier board for colibri VF50, that have an SD holder with the same schematics as other boards (Viola, etc) but the lines are in the limit of length (100mm).
I am going to redesing the board but with the actual one I have the problem that when I insert an SD card, the module tries to read it but some kind of resonaince ocurs and Windows 6.0 (also at bootloader) get locked.
The question: there is any way to slow SD clock in order to build a robust system?
Thank you very much,
Mario Ruiz


You can look into the registry under

HKLM\Drivers\Builtin\ESDHC there is an entry “MaximumClockFrequency” and you can lower it.
But this is only for the OS. Bootloader has fixed frequency.