SDR104 SD3.0 support on Colibri

Technical Support
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1

Hi,

We are trying to bring up SDR104 SD3.0 interface bring up for SDIO3.0 card on Colibri v3.2B board and Colibri iMX7D 1GB emmc SoM. For that we have removed R50,R51,R52,R53,R54 pull up resistors as in schematics link. Still “new ultra high speed SDIO card is not coming” and it is showing up as new high speed SDIO card at address 0x0001. As per the software we enabled SD_1_8 support in imx7_colibri_eval.dtsi file but it is not working and says tuning failed. I am attaching log as well from SDIO card insertion.

So I request you to please responselink text ASAP because it is the show stopper for us.

Thanks,
Sridhar

2

hi @sridhar.jonnavittula

Could you provide the version of the hardware and software of your module?

As per the software we enabled SD_1_8 support in imx7_colibri_eval.dtsi file but it is not working and says tuning failed. I am attaching log as well from SDIO card insertion.

What changes have you done to device tree?
Which SD card are you using? Could you provide the datasheet of the SD Card?

Thanks and best regards,
Jaski

3

Colibri boot log

Hi Jaski,

Thanks for the quick reply.
We are using Colibri iMX7D 1GB V1.1A SoM and Colibri Evaluation V3.2B.
We built the kernel image using the oe-core(Toradex Yocto BSP).
We have added some prints in the kernel source and found that card is supporting UHS(1.8V).

Kindly check in the above attached log(Colibri boot log) for more details.

Please check the device tree changes below

--- a/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
+++ b/arch/arm/boot/dts/imx7-colibri-eval-v3.dtsi
@@ -352,7 +352,7 @@
  * and must (MUST!!!) not be driven with a voltage higher than 1.8V or
  * the interface will not work.
  */
-/* #define SD_1_8 */
+#define SD_1_8 
 &usdhc1 {
 #ifdef SD_1_8
 	pinctrl-names = "default", "state_100mhz", "state_200mhz";

Which SD card are you using? Could you provide the datasheet of the SD Card?
It is a WiFi card from Qualcomm which claims that it supports SDR104.

Thanks and Regards,
Sridhar

4

Hi
We can reproduce the issue. Do you have a deadline when you need this feature? Will your application work with the current solution or not?

5

Hi,

Thank you for the quick response. Good to hear that you could replicate the issue.
We are a module manufacturing company and testing most of our hardware features with Toradex Apalis / Colibri boards.
Also, planning to buy Ixora boards for our official releases.
We need to verify SDR104 in next few days. Otherwise, it will affect some hardware release plans. So, kindly provide a patch for the fix so that we can move forward with out waiting for the next official BSP release from Toradex.

Thanks

6

And you are aware that other SODIMM pins are on that same rail and will need to be disconnected for any such to work, right?

7

We are not aware of the SODIMM pins configuration. However, SDIO in high speed mode is working fine for us.
SDIO 3.0 / SDR104 is not getting detected. For that we disconnected the resistors (R50 … R54) as suggested by Toradex to allow 1.8v voltage switching.

We tried disconnecting SODIMM 43, 47, 190, 192, 49, 51 and 53 on X11. The SDIO card is not detected (even in SDIO high speed mode) after disconnecting this pins.

Could you please tell us more about which specific SODIMM pins to be disconnected?
Went through the board schematics and found that there are many SODIMM pins.

8

As per Colibri iMX7 Datasheet:

Since the SODIMM pin 69, 71, and 73 are connected to SoC balls that share in the same voltage bank as the main SD interface, these pins will also change their voltage level to 1.8V if the SD card IO voltage is changed. Therefore, use pin 69, 71, and 73 with special care.
9

As @marcel.tx said, we tried disconnecting the SODIMM Pins 71 and 73 and removing R168 on the Colibri Evaluation Board on our side. The UHS-I SD cards are working now but the SDIO card is still failing due to tuning issues.

10

Hi Marcel,

Thank you for the quick update. As per the data sheet.

“Only the CLK, CMD,and DATA[0…3] signals of the standard SD interface can change the voltage to 1.8V”

and

The additional DATA[4…7] support only 3.3V. Therefore, it is not possible to use the 8bit eMMC with the reduced signal voltage

We are using the DATA[0…3] only (i.e., 4bit SDIO). Hence I think it should work.

Please help to come out of this issue.

Thanks,
Sridhar.

11

You will need to disconnect SODIMM 69, 71 and 73. Otherwise, back-feeding may badly influence your experience.

12

Thanks for the support. We will test it and get back to you.:slight_smile:

13

You are very welcome.

14

It is detected as Ultra high speed SDR104.
Thanks for the support.

15

Perfect that it works. Thanks for the feedback.