register description
| SLP_WAKEUP_INT_ST | sleep wakeup interrupt state |
| SLP_REJECT_INT_ST | sleep reject interrupt state |
| WDT_INT_ST | RTC WDT interrupt state |
| BROWN_OUT_INT_ST | brown out interrupt state |
| MAIN_TIMER_INT_ST | RTC main timer interrupt state |
| SWD_INT_ST | super watch dog interrupt state |
| BBPLL_CAL_INT_ST | Need add desc |