Which pin is for detecting USDHC2 card insert in i.MX8M Mini manufacture mode?

[m_c]

In i.MX8M Mini reference manual <http://nxp.com/doc/imx8mmrm>, 6.1.2.4 it said "Before going into USB serial mode, Boot ROM detect SD/MMC card on USDHC2 port. If a card is inserted, ROM will try to boot from it. This is the so-called Manufacture SD/MMC boot".

But in table 6-22, the CD_B of USDHC2 is empty.

So which pin is for detecting USDHC2 card insert in i.MX8M Mini manufacture mode?

[marcelziswiler]

I tried both CD_B as well as DATA3 on USDHC2, however, so far without any luck. As the reference manual is seriously lacking properly documenting exact usage of the manufacture mode, can somebody please confirm whether or not and how exactly this actually truly works? Thanks!

[fernando_lopes]

Hi Marcel,

did you solve this problem?

I am working on a board design that will use i.MX8M Mini and it will need to boot from the SD Card. Maybe your experience can help me to make a board that works.

[ankitr_patel · Accepted solution]

Hi m.c,

As described in RM topic:

10.3.3.7 Card insertion and removal detection

"The uSDHC module uses either the DATA3 pin or the CD_B pin to detect card insertion or removal. When there is no card on the MMC/SD bus, the DATA3 is pulled to a low voltage level by default.
When any card is inserted to or removed from the socket, uSDHC detects the logic value changes on the DATA3 pin and generates an interrupt. When the DATA3 pin is not used for card detection (for example, it is implemented in GPIO), the CD_B pin must be connected for card detection. Whether DATA3 is configured for card detection or not, the CD_B pin is always a reference for card detection. Whether the DATA3 pin or the CD_B pin is used to detect card insertion, uSDHC sends an interrupt (if enabled) to inform the Host system that a card is inserted."

Please refer to 10.3 Ultra Secured Digital Host Controller (uSDHC) in RM for more details

Regards,

Ankit Patel