i.MX RT Crossover MCUsのトピックIMXRT1062 uSDHC WP Pin assignment

IMXRT1062 uSDHC WP Pin assignment

amitmehta — Thu, 11 Jul 2019 12:31:16 GMT

Hi Everyone,

I was going through IMXRT1062 reference manual for eMMC interface using Ultra Secured Digital Host Controller (uSDHC).

So for external pins, they have mentioned that

WP Card write-protect detect If not used(for the embedded memory), tie low to indicate it's not write-protected.

But when I was going through iMXRT1060-evk Rev A2 development board the same pin was not used and while running SDK_2.6.1_EVK-MIMXRT1060 example code usb_device_msc_sdcard . the value of WPSL bit of PRES_STATE register was 1. which as per reference manual is

WPSL: This bit reflects the inverted value of the WP pin of the card socket.

So my question here is if no pin is assigned to WP how the value WPSL bit is 1.

Re: IMXRT1062 uSDHC WP Pin assignment

kerryzhou — Fri, 12 Jul 2019 08:40:07 GMT

Hi Amit Mehta,

I already help you check it with our hardware engineer.

If you want to use the SDHC hardware module, and will check the according pin function, you need to follow the reference manual, if you don't use the WP pin, but you will check the WPSL bit in the code, please assign one pin and connect to low, in the code configure the related pin as the USDHC_WP function.

But if you don't check that pin in the code, you totally don't need to use the WP pin, it is determined by your software code.

About your question WPSL bit is 1 when you didn't connect it, I don't think that is stable enough, and the bit status is not guaranteed if you didn't connect the external pin to ground.

In conclusion, if you want to use the WPSL pin in the code, please follow the RT1060 reference manual suggestions, tie the not used WP pin to ground.

Wish it helps you!

If you still have questions about it, please kindly let me know.

Wish it helps you!
Have a great day,
Kerry

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Re: IMXRT1062 uSDHC WP Pin assignment

amitmehta — Mon, 15 Jul 2019 09:20:07 GMT

Hi kerryzhou‌

Thanks for your reply.

if I am understanding correctly if do not wish to use WP pin so for that I did not need to initialize the same pin in my code. SDK uSDHC will work without same.

Re: IMXRT1062 uSDHC WP Pin assignment

kerryzhou — Mon, 15 Jul 2019 09:25:57 GMT

Hi Amit Mehta,

You are right.

If you don't use it, in your code, you also can don't write the related pin code.

Have a great day,
Kerry

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Re: IMXRT1062 uSDHC WP Pin assignment

amitmehta — Tue, 16 Jul 2019 04:30:08 GMT

Hi kerryzhou‌

Thank You for your help

Re: IMXRT1062 uSDHC WP Pin assignment

kerryzhou — Tue, 16 Jul 2019 05:23:55 GMT

You are welcome!

If you still have questions about this topic, please let me know.

If your question is solved, please help me to mark the correct answer, just to close this case, thank you!

Have a great day,
Kerry

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- If this post answers your question, please click the "Mark Correct" button. Thank you!