How to configure SD/MMC 1.8v on IMX6 platform

[chintakanisiva]

Hello,

     We would like to configure the SDIO /MMC voltage levels in IMX6 platform. We need to configure 1.8v instead of

3.3.v.  Is any kernel configuration / register programming required for this change (or) any iomux register configuration is required to achieve this.

Please any one help with this

Regards,

Siva.

[weidong_sun · Accepted solution]

Hello,siva,

      See following picture:

The above means:

if you use 1.8V voltage at pin NVCC_SD1, The high level on SD1 port will be 1.8V.

if you use 1.8V voltage at pin NVCC_SD2  The high level on SD2 port will be 1.8V.

SD3 and SD4 are the same as SD1 and SD2.

Regards,

Weidong

[admin]

Hi Weidong,

How 's about kerrnel config to make SD port work at 1.8V?

Our board has SD ports that hardware configured to work at 1.8V. But when I use "cat ios" command to check, It show 3.3V as below:

     root@android:/ # cat sys/kernel/debug/mmc0/ios                                

     clock: 52000000 Hz

     vdd: 20 (3.2 ~ 3.3 V)

     bus mode: 2 (push-pull)

     chip select: 0 (don't care)

     power mode: 2 (on)

     bus width: 3 (8 bits)

     timing spec: 5 (invalid)

     root@android:/ #

Could you give me some suggestion?

Thanks.