RTC_CALR register
| CALM | Calibration minus The frequency of the calendar is reduced by masking CALM out of 220 RTCCLK pulses (32 seconds if the input frequency is 32768 Hz). This decreases the frequency of the calendar with a resolution of 0.9537 ppm. To increase the frequency of the calendar, this feature should be used in conjunction with CALP. |
| CALW16 | Use a 16-second calibration cycle period When CALW16 is set to 1’ , the 16-second calibration cycle period is selected.This bit must not be set to 1’ if CALW8=1. Note: CALM[0] is stucked at 0’ when CALW16=‘1’. |
| CALW8 | Use an 8-second calibration cycle period When CALW8 is set to 1’ , the 8-second calibration cycle period is selected. Note: CALM[1:0] are stucked at ‘00’ when CALW8=‘1’. |
| CALP | Increase frequency of RTC by 488.5 ppm 0: No RTCCLK pulses are added. 1: One RTCCLK pulse is effectively inserted every 211 pulses (frequency incresed by 488.5 ppm). This feature is intended to be used in conjunction with CALM, which lowers the frequency of the calendar with a fine resolution. if the input frequency is 32768 Hz, the number of RTCCLK pulses added during a 32-second window is calculated as follows: (512 * CALP) - CALM. |