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I am using a Kinetis mcu (K64) from Freescale now NXP and interface with a SD card.

I am looking to replace the SD card with a emmc (8 GB) from Sandisk (WD - Western Digital).

Can't get an answer from NXP and WD won't reply to email or post on this subject so I'm hoping someone here may have an insight.

The mcu (K64) supports mcc specification 4.2/4.3. The Sandisk device supports 5.1.

Question #1 - Can hardware that supports 4.2/4.3 be used to read and write sectors from a 5.1 emmc device?

Question #2 - If so, are there any unique commands for "trim" and "Bad Sector Management" which are supported on the 5.1 device that will not be able to be executed using 4.2/4.3 hardware (K64)?

The K64's SDHC supports 1, 4, and 8 bit interfaces. I currently use 4 bit for SD card - would use 8 bit with emmc.

The K64 is a 120 mhz ARM M4 mcu.

Thanks

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Question #1 - Can hardware that supports 4.2/4.3 be used to read and write sectors from a 5.1 emmc device?

Probably not. The EMMC spec dropped SPI support around the 4.5 version, and most simpler MCUs do not have eMMC in hardware (OP did not tell us which speicifc model will be used). These would require SPI support in order to be able to talk to the eMMC.

SD cards still support the SPI protocol, which is almost always used with MCUs.

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  • \$\begingroup\$ Sorry for not specifying interface. The SDHC device in the K64 has 4bit and 8bit mmc capability - want to use 8bit \$\endgroup\$ – JHinkle Dec 27 '18 at 18:06
  • \$\begingroup\$ Thanks for replying but I think you made an assumption on the mcu being used as a low end hobby mcu which it is not. \$\endgroup\$ – JHinkle Dec 27 '18 at 20:15

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