About SD card mode operation in i.MX6DQ.

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About SD card mode operation in i.MX6DQ.

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keitanagashima
Senior Contributor I

Dear All,

Hello.

My customer is using android jb4.2.2_1.1.0 (L3.0.35) of i.MX6DQ.

When the "mmc_sd_init_card" function in kernel_imx/src/drivers/mmc/core/sd.c doesn't call "mmc_sd_switch_hs function", which mode does the SD card work?

- SD/SDIO full speed mode (up to 25 MHz)

- SD/SDIO high speed mode (up to 50 MHz)

- SD/SDIO UHS-I mode (up to 208Mhz in SDR mode, up to 50Mhz in DDR mode)

And, when mmc_sd_switch(card,1,0,1,status) function is not called, is there an bad effect?

Best Regards,

Keita

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1 Solution
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igorpadykov
NXP Employee
NXP Employee

Hi Keita

>When the "mmc_sd_init_card" function in kernel_imx/src/drivers/mmc/core/sd.c

>doesn't call "mmc_sd_switch_hs function", which mode does the SD card work?

It works in full speed mode (up to 25 MHz)

>when mmc_sd_switch(card,1,0,1,status) function is not called, is there an bad effect?

No.

Best regards

igor

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371 Views
igorpadykov
NXP Employee
NXP Employee

Hi Keita

>When the "mmc_sd_init_card" function in kernel_imx/src/drivers/mmc/core/sd.c

>doesn't call "mmc_sd_switch_hs function", which mode does the SD card work?

It works in full speed mode (up to 25 MHz)

>when mmc_sd_switch(card,1,0,1,status) function is not called, is there an bad effect?

No.

Best regards

igor

-----------------------------------------------------------------------------------------------------------------------

Note: If this post answers your question, please click the Correct Answer button. Thank you!

-----------------------------------------------------------------------------------------------------------------------

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370 Views
keitanagashima
Senior Contributor I

Hi Igor,

Thank you for your prompt reply.

OK. I got it.

Best Regards,

Keita

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