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K20 + eMMC/MMC + ESDHC

Question asked by Robert Sulley on Apr 10, 2014
Latest reply on Jun 23, 2015 by Axel Richter

Hello all,

 

I'm hoping to pick your brains regarding MQX and the ESDHC driver.....

 

I'm working on a ATEX version of an existing product at the moment. It's a GSM RTU based on the K20. I am replacing a micro SDHC card and socket for a Micron MTFC4GLDDQ-4M eMMC device, basically a BGA with the same connections as an SD/MMC card. Hooking the device up to my PC in single bit mode works fine, fully functional. However, connecting it up to the K20, running MQX with the ESDHC driver, it doesn't want to play ball. The ESDHC driver should be compatible with the MMC protocol, however it reports ESDHC_CARD_UNKNOWN as the card type. I've tried both 4bit and 1bit interfaces with the same result, although it's worth mentioning that MMC interface starts up in 1bit mode regardless.

 

The eMMC device is designed to work with the MMCplus protocol, however this protocol is backwards compatible with the original MMC protocol. This information is of importance because I'm only connecting the device using the first data line and also the ESDHC driver doesn't mention MMCplus being supported.

 

I am still working with the software engineer on resolving this, but I thought it would be useful to ask if anyone has utilised the MMC functionality of the ESDHC driver? or even used an eMMC device with a K20 or similar?

 

 

Thanks for taking the time to read this,

 

 

Kind Regards,

 

Rob

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