SD Card Speed Requirement

Hello all,

I am not sure are there are any requirements or we need to pay attention between the ZYNQ IP where there is a SDIO clock speed.

There are many SD Card speed grade on the market but I am really confuse when standalone I experienced that SDIO clock setting too high result in non-responsive but I am not sure Petalinux will override that setting by any frequency training?

We recommend you use a branded SD card. In general faster cards are better. They will be faster to burn and image to and you may or may not notice slightly better performance with faster cards. Most applications are not dependant on SD card read/writes.

In my experience cheaper/non-branded cards tend to fail faster but I’ve never seen the speed of an SD card as a problem.

For more details you can see here on the SD controller:
https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18842090/SD+controller
This may be useful:
https://support.xilinx.com/s/article/66779?language=en_US
I’m not sure if there is a similar list for Zynq. If anyone finds one, please share the link!

Cathal

So Cath do you mean when the ZYNQ SDIO clock is set to 80M:
image
Class 2 card are still workable?
If so this mean PetatLinux are so smart to undergo freq traning?