What to do with SoloX unused digital pins?

[ScottKerstein]

Hello,

I’m wondering what to do with unused digital pins.  For example, if using 1 of the 4 SD card interfaces, is it okay to leave all those unused pins floating?  The note found in the reference manual was “All digital I/O supplies (NVCC_xxxx) must be powered under normal conditions whether the associated I/O pins are in use or not and associated IO pins need to have a Pullup or Pulldown resistor applied to limit any floating gate current.”

Which would imply to add external pulldown resistors to all unused digital pins, but it's not clear if there are internal resistors.  I don’t see anything in the hardware guide about this.  What value should be used?

Thanks in advance,

Scott

[BiyongSUN]

You can find in the

datasheet IMX6SXAEC.pdf

6.2 19x19 mm Package Information

6.2.1 19x19 mm, 0.8 mm Pitch, 23x23 Ball Matrix

[igorpadykov]

Hi Scott

they can be left unconnected, pull-ups (like 100K Ohm Pull Up) can be configured

using registers (IOMUXC_SW_PAD_CTL_PAD_xx, found in

Chapter 35 IOMUX Controller (IOMUXC) i.MX6SX Reference Manual (rev.0  2/2015)

http://cache.freescale.com/files/32bit/doc/ref_manual/IMX6SXRM.pdf

Best regards

igor

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