STM32H7S7L8H6 interface with eMMC

[JK1234]

Hello Team,

We are planning to use STM32H7S7L8H6 in our new design.

We want to interface IS21EF04GP-JQLI-TR eMMC with STM32H7S7L8H6.

So, for this STM32H7S7L8H6 required only 3.3V supply right?

It will be to communicate with eMMC IS21EF04GP-JQLI-TR.

So, please provide your guidance for this.

Thanks & Regards,

Jignesh Karena

[ELABI.1]

Hi @JK1234,

To interface the IS21EF04GP-JQLI-TR eMMC with the STM32H7S7L8H6, the communication is done via the SDMMC controller integrated into the microcontroller.

The SDMMC (Secure Digital MultiMediaCard) is a hardware component embedded in the MCU that enables efficient communication with various types of memory and storage devices (SD cards, SDIO cards, eMMC) through the microcontroller’s internal AHB bus.

You can take a look at the Reference Manual RM0477 specifically section 59.4 SDMMC operation modes:

 

The first table describes the operating modes of the SDMMC controller. It specifies the maximum speeds, clock frequencies, and signal voltages supported for each mode. Some modes operate at 3.3 V (DS, HS), while the other modes (SDR12, SDR25, DDR50, SDR50, SDR104) operate at 1.8 V.

The second table describes the bus speed modes specific to the eMMC interface via SDMMC.
It provides the maximum speeds in Mbyte/s and the associated clock frequencies for each mode.
It specifies the supported signal voltages for each mode:
Legacy, High Speed SDR, and High-Speed DDR modes support multiple voltages: 3 V, 1.8 V, and 1.2 V.
The High Speed HS200 mode operates only at 1.8 V or 1.2 V.

Therefore, the answer to your question is yes, you can use 3.3 V, but you are limited to specific modes.

Thanks.

Eya

[JK1234]

Hello @ELABI.1 ,

Thanks for sharing detailed information.

Can you please share Hardware design guidelines for reference?

[ELABI.1]

Hi @JK1234, 

You can take a look at this Application Note AN5935, which contains interface signal layout guidelines, specifically in section 10.4.1 SDMMC bus interface.

Thanks,

ELABI.1