Forum Discussion
Altera_Forum
Honored Contributor
18 years agoWhen QII simulator simulates the bidirectional pin (e.g. your bidirectional pin name is bidir_io), it will automatically create the bidir_io~result. bidir_io represents the input channel of the bidirectional pin and bidir_io~result represents the output channel of the bidirectional pin.
Therefore your bidir_io~result displays the correct output when OE=1. As for why bidir_io is X is because you do not set any input vector to it. In short, the QII simulator breaks the bidirectional pin to input (e.g bidir_io) and output (e.g. bidir_io~result) in the simulation waveform. Hope it helps.