Saved FAQ from Freescale.com for information only:
Question. How to work with "HVE" bit of IOMUX in i.MX51 ?
Answer. HVE [High / Low Output Voltage Range] - this relates to supported voltage range. HVE bit should be set to activate internal 3V (3.0 - 3.6) buffers, when external power supply for associated pins is 3V.
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