ENVY24HT_MT_PCTL
stat = envy24ht_rdmt(sc, ENVY24HT_MT_PCTL, 1);
envy24ht_wrmt(sc, ENVY24HT_MT_PCTL, stat | sw, 1);
stat = envy24ht_rdmt(sc, ENVY24HT_MT_PCTL, 1);
envy24ht_wrmt(sc, ENVY24HT_MT_PCTL, stat & sw, 1);