read_sbdshr
status = read_sbdshr(sport, R_DUART_IN_PORT);
mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
delta = read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
intstat = read_sbdshr(sport,
intstat &= read_sbdshr(sport,
read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));