sp_intc_assign_bit
sp_intc_assign_bit(hwirq, REG_INTR_POLARITY, !TEST_STATE(hwirq, _IS_LOW));
sp_intc_assign_bit(hwirq, REG_INTR_CLEAR, 1);
sp_intc_assign_bit(d->hwirq, REG_INTR_MASK, 0);
sp_intc_assign_bit(d->hwirq, REG_INTR_MASK, 1);
sp_intc_assign_bit(hwirq, REG_INTR_TYPE, is_edge);
sp_intc_assign_bit(hwirq, REG_INTR_POLARITY, is_low);
sp_intc_assign_bit(hwirq, REG_INTR_POLARITY, TEST_STATE(hwirq, _IS_LOW));