EMU_CHAN_FXRT
emu_wrptr(sc, ch, EMU_CHAN_FXRT, 0xd01c0000);
emu_wrptr(sc, v->vnum, EMU_CHAN_FXRT, v->fxrt1 << 16);
emu_wrptr(sc, v->vnum, EMU_CHAN_FXRT, ((v->routing[3] << 12) |
emu_wrptr(sc, ch, EMU_CHAN_FXRT, 0xd01c0000);