Datasheet

Value Name Description
6
ALARM_FLAG Output is a copy of the alarm flag
7
PROG_PULSE Duty cycle programmable pulse
Bits 18:16 – OUT0[2:0] R
TCOUT0 Output Source Selection
Value Name Description
0
NO_WAVE No waveform, stuck at ‘0’
1
FREQ1HZ 1 Hz square wave
2
FREQ32HZ 32 Hz square wave
3
FREQ64HZ 64 Hz square wave
4
FREQ512HZ 512 Hz square wave
5
ALARM_TOGGLE Output toggles when alarm flag rises
6
ALARM_FLAG Output is a copy of the alarm flag
7
PROG_PULSE Duty cycle programmable pulse
Bit 15 – HIGHPPM HIGH PPM Correction
If the absolute value of the correction to be applied is lower than 30 ppm, it is recommended to clear HIGHPPM.
HIGHPPM set to 1 is recommended for 30 ppm correction and above.
Formula:
If HIGHPPM = 0, then the clock frequency correction range is from 1.5 ppm up to 98 ppm. The R
TC accuracy is less
than 1 ppm for a range correction from 1.5 ppm up to 30 ppm.
The correction field must be programmed according to the required correction in ppm; the formula is as follows:
CORRECTION =
3906
20 × ppm
 1
The value obtained must be rounded to the nearest integer prior to being programmed into CORRECTION field.
If HIGHPPM = 1, then the clock frequency correction range is from 30.5 ppm up to 1950 ppm. The R
TC accuracy is
less than 1 ppm for a range correction from 30.5 ppm up to 90 ppm.
The correction field must be programmed according to the required correction in ppm; the formula is as follows:
CORRECTION =
3906
ppm
 1
The value obtained must be rounded to the nearest integer prior to be programmed into CORRECTION field.
If NEGPPM is set to 1, the ppm correction is negative (used to correct crystals that are faster than the nominal
32.768 kHz).
Value Description
0
Lower range ppm correction with accurate correction.
1
Higher range ppm correction with accurate correction.
Bits 14:8 – CORRECTION[6:0] Slow Clock Correction
Value Description
0
No correction
1–127
The slow clock will be corrected according to the formula given in HIGHPPM description.
Bit 4 – NEGPPM Negative PPM Correction
See CORRECTION and HIGHPPM field descriptions.
NEGPPM must be cleared to correct a crystal slower than 32.768 kHz.
Value Description
0
Positive correction (the divider will be slightly higher than 32768).
1
Negative correction (the divider will be slightly lower than 32768).
Bit 1 – PERSIAN PERSIAN Calendar
Value Description
0
Gregorian calendar.
1
Persian calendar.
Bit 0 – HRMOD 12-/24-hour Mode
Value Description
0
24-hour mode is selected.
SAM E70/S70/V70/V71 Family
Real-time Clock (RTC)
© 2019 Microchip T
echnology Inc.
Datasheet
DS60001527D-page 216