Question, i.MX6Solo USDHC#3 / SDR50 or SDR104

[Aemj]

Dear team,

I would like to ask about the setting for USDHC#3 of i.MX6SOLO.

My customer is trying to use USDHC#3 of i.MX6SOLO with SDR50 or SDR104 on Linux.

On their board, the power switching circuitry for SD-Card is designed based on your SABRE-AI board.

Now SD3_VSELECT cannot become HIGH on their board. And they saw the VSELCT can be controlled when they removed 4.7K ohm pull-down register from VSELECT line.

They think 4.7K ohm pull-down register is needed similarly to SABRE AI board.

Do you have any ideas for the cause of this phenomenon?

Thanks,

Miya

[Yuri · Accepted solution]

Hello,

  Basically the SD3_VSELECT can be configured via

IOMUXC_SW_PAD_CTL_PAD_GPIO18

and

IOMUXC_SW_MUX_CTL_PAD_GPIO18

Please check if their configuration is correct.

  Also, please refer to the following Question, i.MX6Solo / data transfer speed of SD-Card Boot

https://community.nxp.com/message/655400#comment-655400

Have a great day,
Yuri

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[Aemj]

Hi Yuri,

After the customer’s investigation, VSELECT came to be working now. And power supply to SD-Card can be changed from 3.3 to 1.8V.

For their board, IOMUXC_SW_PAD_CTL_PAD_GPIO18 = 0x1759 now.

Now they are facing the issue that the communication between i.MX6S and SD-card stops.

After changing to 1.8V, device driver detect time-out after issuing CMD2.

That is, SD card seems not to send any reply after CMD2 from i.MX.

And SD3_RST goes to LOW.

Do you have any ideas about the cause of this issue?

If I have to create a new, please let me know.

BR,

Miyamoto