PDC_TNPR
bus_space_write_4(iot, ioh, offset + PDC_TNPR, fifo->f_buf_addr);
bus_space_write_4(iot, ioh, offset + PDC_TNPR, fifo->f_buf_addr + fifo->f_pdc_rd_ndx);
PUTREG(sc, SPI_PDC_BASE + PDC_TNPR, sc->sc_dmaaddr + sc->sc_dmaoffs);