Can i.MX6 SDHC issue ACMD42?

[torus1000]

Hi,

I just want to confirm a SDHC command supported by i.MX6.

Does ROM code issue ACMD42(SET_CLR_CARD_DETECT) during boot?

Can uboot support ACMD42 to enable internal pull-up resistor inside the SD card?

Can anybody help me?

Reference:
https://e2e.ti.com/support/arm/sitara_arm/f/791/t/232955
The DAT3/CD card detection mechanism involves an internal pull-up resistor inside the SD card,
which can be controlled by ACMD42 (SET_CLR_CARD_DETECT). However the specification says that
this is not a preferred mechanism for card detection. Moreover it won't work with MMC cards.
And last, this won't work with external pull-up resistors on the card interface.
The preferred card detection mechanism is a mechanical switch on the card connector.

[igorpadykov · Accepted solution]

Hi torus1000

ACMD42 can be produced by usdhc module according to

Table 67-6. Commands for MMC/SD/SDIO Cards i.MX6DQ Reference Manual
http://www.nxp.com/docs/en/reference-manual/IMX6DQRM.pdf

Uboot (used in NXP BSPs) and ROM do not use ACMD42.

Best regards
igor
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