R_DUART_AUXCTL_X
write_sbdchn(sport, R_DUART_AUXCTL_X,
write_sbdchn(sport, R_DUART_AUXCTL_X, 0);
oldaux = read_sbdchn(sport, R_DUART_AUXCTL_X) & auxmask;
write_sbdchn(sport, R_DUART_AUXCTL_X, aux | oldaux);