DC_CMD_INT_MASK
WR4(sc, DC_CMD_INT_MASK, 0);
WR4(sc, DC_CMD_INT_MASK,
val = RD4(sc, DC_CMD_INT_MASK);
WR4(sc, DC_CMD_INT_MASK, val);
val = RD4(sc, DC_CMD_INT_MASK);
WR4(sc, DC_CMD_INT_MASK, val);
val = RD4(sc, DC_CMD_INT_MASK);
WR4(sc, DC_CMD_INT_MASK, val);