ENVY24_MT_PCNT
regno = ENVY24_MT_PCNT;
device_printf(sc->dev, "PCNT:%ld\n", envy24_rdmt(sc, ENVY24_MT_PCNT, 2));
ptr = dsize - envy24_rdmt(sc, ENVY24_MT_PCNT, 2) - 1;
envy24_wrmt(sc, ENVY24_MT_PCNT, sc->psize / 4 - 1, 2);
device_printf(sc->dev, "PCNT-->(%ld)\n", envy24_rdmt(sc, ENVY24_MT_PCNT, 2));