Unused MMC2 and GPI pins on DM3730

Yannick Fortin said:

There is a recommendation saying to use 5-10k resistors on MMC1 signals when VDDS_MMC1a is not used (see AM37x/DM37x Schematics Checklist). What about the MMC2 interface? Is it OK to leave them unconnected when MMC2 is not used?

Depending on which pins you are referencing, you will find in the Ball Characteristics table (Table 2-1) of the DM3730 datasheet and indicatation of the state of the pin after the release of reset and which mode it is operating in.  See my comments below for possible treatment of those signals.

Yannick Fortin said:

  Also, there is a list of GPIOs that are INPUT only in the DM3730 (GPIO99,100,105,106,107,108,112,113,114,115). Is it OK to leave those floating when not used?

You will see in the Ball Characteristics table (Table 2-1) of the DM3730 datasheet a column which indicates the state of the pin after the release of reset and which mode it is in.  For the GPIO pins you mention above, these all default to the internal pulldown enabled and are in safe mode.

Therefore, if you do not route these signals on your PCB, you can leave them floating, or unconnected.  This is because the internal pulldown will keep these pins in a known state.

However, if you route these pins to a test point on the board, then my advice would be to have an external pull down resistor on them.  The reason is that the trace on the board will potentially pick up noise or couple to other signals and potentially raise the voltage to a level beyond the Vil limit.  This would add to power consumption, etc.