rtc_get_datetime: read the rtc registers just once each
In order for the returned value to accurately reflect a single moment in time, ensure the registers are read just once and in the datasheet order. Before this change, the RTC registers would each be read multiple times, leading (infrequently) to the returned fields not all reflecting the same moment in time. The rp2040 datasheet has what I believe is an incorrect example (embedding the source of this function); will the datasheet be updated if this function is fixed? This problem is only a speculative one; I did not actually observe it in the wild.
This commit is contained in:
parent
f76567eb7f
commit
e9a521a9b1
@ -92,13 +92,16 @@ bool rtc_get_datetime(datetime_t *t) {
|
|||||||
}
|
}
|
||||||
|
|
||||||
// Note: RTC_0 should be read before RTC_1
|
// Note: RTC_0 should be read before RTC_1
|
||||||
t->dotw = (rtc_hw->rtc_0 & RTC_RTC_0_DOTW_BITS ) >> RTC_RTC_0_DOTW_LSB;
|
uint32_t rtc_0 = rtc_hw->rtc_0;
|
||||||
t->hour = (rtc_hw->rtc_0 & RTC_RTC_0_HOUR_BITS ) >> RTC_RTC_0_HOUR_LSB;
|
uint32_t rtc_1 = rtc_hw->rtc_1;
|
||||||
t->min = (rtc_hw->rtc_0 & RTC_RTC_0_MIN_BITS ) >> RTC_RTC_0_MIN_LSB;
|
|
||||||
t->sec = (rtc_hw->rtc_0 & RTC_RTC_0_SEC_BITS ) >> RTC_RTC_0_SEC_LSB;
|
t->dotw = (rtc_0 & RTC_RTC_0_DOTW_BITS ) >> RTC_RTC_0_DOTW_LSB;
|
||||||
t->year = (rtc_hw->rtc_1 & RTC_RTC_1_YEAR_BITS ) >> RTC_RTC_1_YEAR_LSB;
|
t->hour = (rtc_0 & RTC_RTC_0_HOUR_BITS ) >> RTC_RTC_0_HOUR_LSB;
|
||||||
t->month = (rtc_hw->rtc_1 & RTC_RTC_1_MONTH_BITS) >> RTC_RTC_1_MONTH_LSB;
|
t->min = (rtc_0 & RTC_RTC_0_MIN_BITS ) >> RTC_RTC_0_MIN_LSB;
|
||||||
t->day = (rtc_hw->rtc_1 & RTC_RTC_1_DAY_BITS ) >> RTC_RTC_1_DAY_LSB;
|
t->sec = (rtc_0 & RTC_RTC_0_SEC_BITS ) >> RTC_RTC_0_SEC_LSB;
|
||||||
|
t->year = (rtc_1 & RTC_RTC_1_YEAR_BITS ) >> RTC_RTC_1_YEAR_LSB;
|
||||||
|
t->month = (rtc_1 & RTC_RTC_1_MONTH_BITS) >> RTC_RTC_1_MONTH_LSB;
|
||||||
|
t->day = (rtc_1 & RTC_RTC_1_DAY_BITS ) >> RTC_RTC_1_DAY_LSB;
|
||||||
|
|
||||||
return true;
|
return true;
|
||||||
}
|
}
|
||||||
|
Loading…
Reference in New Issue
Block a user