On p96 of C6672 datasheet, there is the power supply to peripheral I/O mapping. For DVDD18 (1.8V supply I/O voltage), the I/O Buffer Type is DDR3 (1.5V). Why is the supply voltage 1.8V but the I/O buffer type linked to 1.5V? What do you mean when you say the I/O buffer type is DDR3 (1.5V)?