R_DUART_MODE_REG_2
__read_sbdchn(sport, R_DUART_MODE_REG_2);
mode2 = read_sbdchn(sport, R_DUART_MODE_REG_2);
write_sbdchn(sport, R_DUART_MODE_REG_2, mode2);
write_sbdchn(sport, R_DUART_MODE_REG_2, 0);
oldmode2 = read_sbdchn(sport, R_DUART_MODE_REG_2) & mode2mask;
write_sbdchn(sport, R_DUART_MODE_REG_2, mode2 | oldmode2);