How to configure SD/MMC 1.8v on IMX6 platform

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

How to configure SD/MMC 1.8v on IMX6 platform

Jump to solution
1,923 Views
chintakanisiva
Contributor II

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.

Labels (2)
0 Kudos
1 Solution
722 Views
weidong_sun
NXP TechSupport
NXP TechSupport

Hello,siva,

      See following picture:

SD-1V8.png

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

View solution in original post

0 Kudos
2 Replies
723 Views
weidong_sun
NXP TechSupport
NXP TechSupport

Hello,siva,

      See following picture:

SD-1V8.png

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

0 Kudos
722 Views
admin
Specialist II

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.

0 Kudos