PMACZILOG_FLAG_TX_ACTIVE
uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE;
uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
uap->flags |= PMACZILOG_FLAG_TX_ACTIVE;
#define ZS_TX_ACTIVE(UP) ((UP)->flags & PMACZILOG_FLAG_TX_ACTIVE)