Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD Hoja De Datos

 268

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

Name: RTC_MR

0x400E1464

Access: Read-write 

0 = 24-hour mode is selected.

1 = 12-hour mode is selected.

0 = Gregorian Calendar.

1 = Persian Calendar.

0 = positive correction (the divider will be slightly lower than 32768).

1 = negative correction (the divider will be slightly higher than 32768).

Refer to CORRECTION and HIGHPPM field descriptions.

0 = No correction

1..127 = The slow clock will be corrected according to the formula given below in HIGHPPM description.

0 = lower range ppm correction with accurate correction.

1 = higher range ppm correction with accurate correction.

If the absolute value of the correction to be applied is lower than 30ppm, 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 RTC 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:

 

31

30

29

28

27

26

25

24

–

–

TPERIOD

–

THIGH

23

22

21

20

19

18

17

16

–

OUT1

–

OUT0

15

14

13

12

11

10

9

8

HIGHPPM

CORRECTION

7

6

5

4

3

2

1

0

–

–

–

NEGPPM

–

–

PERSIAN

HRMOD

3906

20

×

------------------------

1

–

=