eMMC 4.4 vs 4.5

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eMMC 4.4 vs 4.5

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JHY
Contributor IV

I.MX6 can support eMMC 4.4 / 4.41.

So my question is that whether it is possible eMMC 4.5.

What will happen in that case?

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igorpadykov
NXP Employee
NXP Employee

Hi

booting from a eMMC 4.5 device is not supported,  boot ROM will fall back to the

eMMC4.4  standard when a eMMC4.5 capable device is detected.

In BSP it is possible to bypass eMMC version checking, so that eMMC v4.5 can

work as eMMC v4.4 cards, no specific v4.5 feature supported.

Only basic read/write operations are supported.

static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)

     }

     card->ext_csd.rev = ext_csd[EXT_CSD_REV];

-    if (card->ext_csd.rev > 5) {

+    /* workaround: support emmc 4.5 cards to work at emmc 4.4 mode */

+    if (card->ext_csd.rev > 6)

Best regards

igor

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1,048 次查看
igorpadykov
NXP Employee
NXP Employee

Hi

booting from a eMMC 4.5 device is not supported,  boot ROM will fall back to the

eMMC4.4  standard when a eMMC4.5 capable device is detected.

In BSP it is possible to bypass eMMC version checking, so that eMMC v4.5 can

work as eMMC v4.4 cards, no specific v4.5 feature supported.

Only basic read/write operations are supported.

static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)

     }

     card->ext_csd.rev = ext_csd[EXT_CSD_REV];

-    if (card->ext_csd.rev > 5) {

+    /* workaround: support emmc 4.5 cards to work at emmc 4.4 mode */

+    if (card->ext_csd.rev > 6)

Best regards

igor

-----------------------------------------------------------------------------------------------------------------------

Note: If this post answers your question, please click the Correct Answer button. Thank you!

-----------------------------------------------------------------------------------------------------------------------

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