LPC1788FBD208 support read/write 4 bit bus mode eMMC ?

[thinkking1985]

LPC1788 SDIO support:

1:Conformance to Secure Digital Memory Card Physical Layer Specification, v0.96.
2:Conformance to Multimedia Card Specification v2.11.

To my question:

1:LPC1788FBD208  SDIO controller support  4-bit bus mode's eMMC ?

2:NXP have  demo code to support read/write 4-bit bus mode's eMMC?

Thanks a lot for NXP great support.

[Alexis_A]

Hello Alvin,

The SD module can also support eMMC memories, the module has 4 data lines so it can support 4-bit bus mode.

In the following link, you can find a driver and example package called LPCOpen, in this, you can find an example called app_sdmmc_meas that shows how to configure the module.

Best Regards,

Alexis Andalon

[thinkking1985]

Why is it not successful to set the bus width to 4bit in MMC mode? Why is it clear in the NXP official routine that the line width below MMC V4 does not support 4bit.

Tks a  lot for your support.

[Alexis_A]

Dear thinkking1985‌,

Can you let me know where did you find that note? In the RM mention that you would need to enable the WIDEBUS in the CLOCK register:

Best regards,

Alexis Andalon

[thinkking1985]

Hi Alexis

I think it is not support 4bit mode .

[Alexis_A]

Hello Alvin,

You're totally right, the 4-bit support is only for secure digital memory card interfaces. 

Best Regards,

Alexis Andalon