iCE40: How to identify true (positive) and complementary (negative) ball functions for Low Voltage Differential Signaling (LVDS) inputs in iCE40 device?
The differential signals ending with 'B' in the Pinout file represent
the positive end, and the differential signals ending with 'A'
represent the negative end.
For example, in the Pinout file, IOL_3A and IOL_3B are differential pins (DPIO).
So, IOL_3B is considered true (positive) signal, and IOL_3A is considered complementary (negative) signal.