CH_BAUD0
ch->ch_flags |= (CH_BAUD0);
if (ch->ch_flags & CH_BAUD0)
ch->ch_flags &= ~(CH_BAUD0);
ch->ch_flags |= (CH_BAUD0);
if (ch->ch_flags & CH_BAUD0)
ch->ch_flags &= ~(CH_BAUD0);