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SD Card Reliability Problems

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jlavie
Junior(0)
SD Card Reliability Problems

I have been experiencing SD Card problems with 2 of the PZSDR SOMs. I would like to know if any other PZSDR users are having the same problem.

On one SOM, the unit suddenly failed to boot. I reseated the SD Card and the boot problem was fixed. The failure to boot later happened again (3 times total) and reseating the SD Card always returned the SOM to booting successfully. 2 times the SOM failed to boot on our custom carrier board and one time it failed to boot on the Avnet carrier board. Finally I replaced the SD Card and the boot problem has not returned so far.

On another SOM, the unit would boot, but Linux could not read the files on the SD Card (/mnt/mmc was empty) after boot 80% of the time. I changed to a different SD Card and the problem has not returned so far.

Thanks in advance for any info!
John LeVieux
 

JFoster
Moderator(69)
Hi John,

Hi John,

What kind of SD Card are you using? May I ask are you using a SD Card that came with your board? If not, would you please check and see if your SD card is complient with the SD Card advice document that we have created for Zynq 7000 SOC products. 

http://zedboard.org/content/sd-card-advice-zynq-7000-soc-products-0

Thanks,

Josh

jlavie
Junior(0)
Josh,

Josh,

I am using about 4 different kinds of SD Cards. None of those SD Cards came with the SOM.

I will describe the 2 kinds that resulted in failures.

1. Samsung 32GB UHS-I speed class 1 EVO series - This SD Card worked for a long time (many months) then started failing. The SOM stopped booting, I re-seated the SD Card in the connector and then the SD Card began working again. The same failure and fix repeated 3 times until I replaced the SD Card with another unit of the exact kind from Samsung. So far the replacement SD Card is not failing.

This Samsung SD Card is UHS speed and therefore not recommended according to the Avnet SD Card advice document. However, the recommendation is confusing since the SD Card supplied with the PicoZed board is also a UHS speed SD Card (SanDisk 32GB UHS-I speed class C10 Ultra series).

2. SanDisk 2GB - This SD Card started failing to read the files on the SD Card (empty directory /mnt/mmc). It would fail after 80% of the boots. I replaced the SD card with another kind (Samsung 32GB UHS-I speed class 1 EVO series) and the failure never happened again.

This SD Card is not physically marked for the speed, so I can't tell if it is high-speed or standard-speed. In any case, my understanding this that all SD Card v2.0 controllers are required to be backward compatible with earlier SD Card v1.1 devices.

In conclusion, it is not clear to me if my SD Cards should work or not. It would be helpful to know if other PicoZed users are having similar issues and may have more information to help me pinpoint the problem. Do you have any other cases to share?

Thanks!
John
 

JFoster
Moderator(69)
Hi jlavie.

Hi jlavie.

1. your Samsung 32GB UHS-I is not a suggest SD Card solution, please look at section 4 of the SD Card advice document.

2. I do not know the speed grade so i can no comment on if there should be an issue or not.

 

Please refer to page 6 of that document and it contains a list of various proven SD Cards that I would suggest you choose from.

--Josh