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iMX7D boot USDHC3 1V8

Question asked by Thomas Kofoed Hansen on Mar 20, 2017
Latest reply on Mar 21, 2017 by igorpadykov

It's possible to set the voltage for ports USDHC1-2 via pull-up/down resistors on the LCD BOOT_CFG pins, but the USDHC3 setting has to be done by sw.

 

I would like to boot from the USDHC3 interface connected to an eMMC with 1V8 IO voltage, because it's the eMMC port that supports the fastest interface (HS400 using strobe). But the default register (0x4A0[1]) setting is 3V3, so my question is is there any way to accomplish what I want?

 

Another question is why are these voltage settings necessary, does the CPU actually change the pin voltage according to these settings regardless of what the GPIO power bank is connected to?

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