LPC Microcontrollers中的主题 Re: LPC1788FBD208 support read/write 4 bit bus mode eMMC ?

LPC1788FBD208 support read/write 4 bit bus mode eMMC ?

thinkking1985 — Mon, 13 Jul 2020 02:24:19 GMT

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.

Re: LPC1788FBD208 support read/write 4 bit bus mode eMMC ?

Alexis_A — Wed, 15 Jul 2020 02:16:28 GMT

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

Re: LPC1788FBD208 support read/write 4 bit bus mode eMMC ?

thinkking1985 — Wed, 15 Jul 2020 03:12:16 GMT

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.

Re: LPC1788FBD208 support read/write 4 bit bus mode eMMC ?

Alexis_A — Thu, 16 Jul 2020 21:59:05 GMT

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

Re: LPC1788FBD208 support read/write 4 bit bus mode eMMC ?

thinkking1985 — Fri, 17 Jul 2020 15:36:41 GMT

Hi Alexis

I think it is not support 4bit mode .

Re: LPC1788FBD208 support read/write 4 bit bus mode eMMC ?

Alexis_A — Thu, 23 Jul 2020 23:37:34 GMT

Hello Alvin,

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

Best Regards,

Alexis Andalon