read_dbreg
write_dbreg(reg, read_dbreg(reg) | irq_mask);
write_dbreg(reg, read_dbreg(reg) & ~irq_mask);
uint32_t cause = read_dbreg(DOVE_DB_MICR);
uint32_t pending = read_dbreg(DOVE_DB_MIRQIMR);
uint32_t cause2 = read_dbreg(DOVE_DB_SMICR);
uint32_t pending2 = read_dbreg(DOVE_DB_SMIRQIMR);