FRDM-K64F SDHC init problem

rothkarl — Wed, 28 Oct 2015 17:51:14 GMT

Hello everyone!

I am developing a FAT stack for SDHC cards for my MSC thesis, and I have faced with some problems at the very beginnings.

I am trying to initialize my SDHC card from my fimrware but at this point I have stucked:

-First of all, in my configuration I am using SDHC peripheral

-After power up I issue a CMD0 SW reset command to the SDHC card, but I cannot get back the so called R1 response data

-Following up the mandatory routine I issue a CMD8 command, to check voltage range support of the card, and it responds back with

the same pattern, in case I sent valid paramters. This signs that the communication at phy layer should be ok.

-The problem arises when I am issuing ACMD41 command, with 0 Voltage level argument, but I cannot get back the OCR register content of the card. Instead the response register of the micro contains the previous respond. The problem is, that I have not figured out yet, that how could I determine that the micro have not received valid response, however every flag signs that a command successfully executed, and no error flags signs other.

In that case I send invalid parameters as CMD8 argument, that the previous content of the response register remains the same. This terminology means that no response were received (as Phy specification also says: In that case CMD8 args are invalid, that SD card not responds). But the problem is, that I have experienced the same when issuing ACMD41 command, and other commands, I simply cannot get valid answers, and from the sw point of view I am unable to determine that the response fields containing valid data or some previous data.

I am looking for the help of professionals who have deeper lever experience in this case.

Thank you very much in advance!

Re: FRDM-K64F SDHC init problem

Carlos_Musich — Fri, 06 Nov 2015 17:32:17 GMT

Hi Roth,

you may find useful this post https://community.freescale.com/docs/DOC-105852

Regards,

Carlos

topic Re: FRDM-K64F SDHC init problem in Kinetis Microcontrollers

FRDM-K64F SDHC init problem

Re: FRDM-K64F SDHC init problem