We're working on a port of our SD card drivers to the i.MX31 and it appears that the voltage fed to the SD card socket on the Baseboard from the i.MX31 SOM is 1.8V. That pretty much rules out any common SD cards working there (although MMC Mobile cards will probably support the lower voltage, we need/want 4-bit SD mode for speed and availability of product in the channel). 1.8V only to the SD slot then is a problem for us...

In looking at the schematics, it would appear that I can isolate the NVCC3 net from the 1.8V rail by removing R30. I'm a little leary to just try it though since schematics don't always equal the actual board that shipped. (maybe there's another net tied to NVCC3 somewhere that requires the 1.8V rail?)

So, my question then-- is it 'safe' to simply pull R30 to isolate NVCC3 from the 1.8V rail and instead jumper 2.7V over to the NVCC3 rail to get standard SD cards working? (AKA, 2.7-3.3V operation only)

Thanks,
-Clay