ENVY24HT_MT_INT_RMASK
mask = ~ENVY24HT_MT_INT_RMASK;
mask = ENVY24HT_MT_INT_RMASK;
stat = ENVY24HT_MT_INT_RSTAT | ENVY24HT_MT_INT_RMASK;
envy24ht_wrmt(sc, ENVY24HT_MT_INT_MASK, stat | ENVY24HT_MT_INT_RMASK, 1);