
294
SAM4CP [DATASHEET]
43051E–ATPL–08/14
The correction field must be programmed according to the required correction in ppm, the formula is as follows:
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 RTC 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:
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 crystal that are faster than the nominal 32.768 kHz).
OUT0: RTCOUT0 Output Source Selection
THIGH: High Duration of the Output Pulse
TPERIOD: Period of the Output Pulse
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
Value
Name
Description
0
H_31MS
31.2 ms
1
H_16MS
15.6 ms
2
H_4MS
3.91 ms
3
H_976US
976
μ
s
4
H_488US
488
μ
s
5
H_122US
122
μ
s
6
H_30US
30.5
μ
s
7
H_15US
15.2
μ
s
Value
Name
Description
0
P_1S
1 second
1
P_500MS
500 ms
2
P_250MS
250 ms
3
P_125MS
125 ms
CORRECTION
20
ppm
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1
–
=
CORRECTION
ppm
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1
–
=