OPENPIC_IACK
return u3_ht_read(u3_ht, OPENPIC_IACK(cpu)) & OPENPIC_VECTOR_MASK;
const uint32_t iack = openpic_read(cpu, OPENPIC_IACK);
return openpic_read(OPENPIC_IACK(cpu)) & OPENPIC_VECTOR_MASK;