sc_reg_fifo
bus_space_read_1(t, h, fdc->sc_reg_fifo);
bus_space_write_1(t, h, fdc->sc_reg_fifo, x);
bus_space_read_1(t, h, fdc->sc_reg_fifo);
bus_space_write_1(t, h, fdc->sc_reg_fifo,
fdc->sc_reg_fifo = FDREG77_FIFO;
fdc->sc_reg_fifo = FDREG72_FIFO;
bus_space_read_1(t, h, fdc->sc_reg_fifo);
bus_space_write_1(t, h, fdc->sc_reg_fifo, x);
bus_space_read_1(t, h, fdc->sc_reg_fifo);
bus_space_write_1(t, h, fdc->sc_reg_fifo,
fdc->sc_reg_fifo = FDREG77_FIFO;
fdc->sc_reg_fifo = FDREG72_FIFO;
*fdc->sc_data++ = *fdc->sc_reg_fifo;
*fdc->sc_reg_fifo = *fdc->sc_data++;
fdc->sc_reg_fifo = &((struct fdreg_72 *)fdc->sc_reg)->fd_fifo;
fdc->sc_status[n++] = *fdc->sc_reg_fifo;
*fdc->sc_reg_fifo = x;