Using external emmc with Colibri Imx8x

Technical Support
, ,
1

I am trying to use SDINBDG4-8G-I2 with the colibri-imx8x.

Can I wire this chip using the SD Card line as it is on the Colibri Evaluation Board?
Would I need to change anything in the device tree for this device to show up ?

2

Unfortunately, we are not familiar with the SDINBDG4-8G-I2, and the publicly available datasheet does not provide enough information to answer your question. It may be possible to connect it to a conventional 4-wire SD card interface, but to confirm compatibility and learn the specific method of connection, we suggest contacting SanDisk directly

3

I was able to acquire the data sheet from Sandisk. Can you please confirm this is compatible with Colibri imx8x?

I have DAT_0 - DAT_4 connected to MMC_DAT_0 - MMC_DAT_4 on Colibri with 10k pullups.

DAT_5_- DAT_7 are connect to 3.3V via a 10K pull up.

Datasheet attached.
Data sheet - IX EM122 02-05-WW-04-00159 v2.2.PDF (2.3 MB)

4

The datasheet does not clearly indicate if the chip is capable of emulating an SD card interface. Additionally, the reference schematic depicts an 8-bit data bus connection, whereas an Colibri SD card interface has only 4 data lines. To obtain clarification on whether this chip can be connected using the standard SD card interface, please reach out to SunDisk/Western Digital.

5

I reached out to SanDisk and as per them if the SD port I am connecting to supports a eMMC protocol the chip should work.

Can you please confirm the SD port support the eMMC protocol and how do I configure it for that ?

6

"Could you please specify which exact eMMC protocol you are referring to? Then, I will be able to confirm whether the Colibri iMX8X SD port supports it.

According to the datasheet, the SDINBDG4-8G-I2 supports only the eMMC 5.1 HS400 interface. And this document states that HS400 requires an 8-bit bus width, while the Colibri SD card interface has only 4 data lines. I wasn’t able to find any SanDisk documentation stating that the SDINBDG4-8G-I2 supports a 4-bit interface. Have you managed to obtain this information directly from SanDisk, as I previously suggested?

7

Yes I reached out to SanDisk and they said the chip should work.

I made the following changes to the colibri-imx8x.dtsi and it seems to be working:

 /* Colibri PWM_B */
@@ -839,13 +862,13 @@ &usdhc2 {
        bus-width = <4>;
        cd-gpios = <&lsio_gpio3 9 GPIO_ACTIVE_LOW>;
        vmmc-supply = <&reg_module_3v3>;
-       pinctrl-names = "default", "state_100mhz", "state_200mhz", "sleep";
+       non-removable;
+       no-sd;
+       no-sdio;
+       pinctrl-names = "default", "state_100mhz", "state_200mhz";
        pinctrl-0 = <&pinctrl_usdhc2>, <&pinctrl_usdhc2_gpio>;
        pinctrl-1 = <&pinctrl_usdhc2_100mhz>, <&pinctrl_usdhc2_gpio>;
        pinctrl-2 = <&pinctrl_usdhc2_200mhz>, <&pinctrl_usdhc2_gpio>;
-       pinctrl-3 = <&pinctrl_usdhc2_sleep>, <&pinctrl_usdhc2_gpio_sleep>;
-       disable-wp;
-       no-1-8-v;
 };