FM3130 Integrated RTC/Alarm with 64Kb FRAM
24
25
26
27
28
29
30
31
511.9478
511.9456
511.9433
511.9411
511.9389
511.9367
511.9344
511.9322
511.9456
511.9433
511.9411
511.9389
511.9367
511.9344
511.9322
511.9300
102.00
106.34
110.68
115.02
119.36
123.70
128.04
132.38
106.33
110.67
115.01
119.35
123.69
128.03
132.37
136.71
111000
111001
111010
111011
111100
111101
111110
111111
Negative Calibration for fast clocks: Calibration will achieve 2.17 PPM after calibration
Measured Frequency Range Error Range (PPM)
Min
Max
Min
0
2.18
Max
2.17
6.51
Program Calibration Register to:
0
1
2
3
4
5
6
7
8
512.0000
512.0011
512.0033
512.0056
512.0078
512.0100
512.0122
512.0144
512.0167
512.0189
512.0211
512.0233
512.0256
512.0278
512.0300
512.0322
512.0344
512.0367
512.0389
512.0411
512.0433
512.0456
512.0478
512.0500
512.0522
512.0544
512.0567
512.0589
512.0611
512.0633
512.0656
512.0678
512.0011
512.0033
512.0056
512.0078
512.0100
512.0122
512.0144
512.0167
512.0189
512.0211
512.0233
512.0256
512.0278
512.0300
512.0322
512.0344
512.0367
512.0389
512.0411
512.0433
512.0456
512.0478
512.0500
512.0522
512.0544
512.0567
512.0589
512.0611
512.0633
512.0656
512.0678
512.0700
000000
000001
000010
000011
000100
000101
000110
000111
001000
001001
6.52
10.85
15.19
19.53
23.87
28.21
32.55
36.89
41.23
45.57
49.91
54.25
58.59
62.93
67.27
71.61
75.95
80.29
84.63
88.97
93.31
97.65
10.86
15.20
19.54
23.88
28.22
32.56
36.90
41.24
45.58
49.92
54.26
58.60
62.94
67.28
71.62
75.96
80.30
84.64
88.98
93.32
97.66
102.00
106.34
9
E
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
001010
001011
001100
T
001101
001110
001111
010000
010001
010010
010011
t
n
e
E
p
m
010100
010101
4
L
e
6
c
010110
010111
011000
011001
011010
101.99
106.33
110.67
1
a
l
3
O
110.68
115.02
119.36
115.01
119.35
123.69
128.03
e
M
011011
011100
F
R
123.70
011101
011110
011111
S
128.04
:
t
132.37
132.38
136.71
e
c
v
e
i
tri-stated by reading the AF flag, located in the
RTC/Alarm Control register 00h.
B
r
t
Alarm
i
a
The alarm function compares user-programmed
D
n
alarm values to the corresponding RTC time/date
There are five alarm match fields. They are Month,
r
values. When a match occurs, an alarm event occurs.
Date, Hours, Minutes, and Seconds. Each of these
o
O
e fields also has a Match bit that is used to determine if
The alarm event sets an internal flag AF (register
t
00h, bit 6) and drives the ACSNpin low, if the
l
the field is used in the alarm match logic. Setting the
Match bit to „0‟ indicates that the corresponding field
will be used in the match process.
appropriate control bits are set in registers 00h and
A
0Eh. See Table 3. The alarm condition on the ACS
pin and the AF bit are cleared by reading register
00h.
Depending on the Match bits, the alarm can occur as
specifically as one particular second on one day of
the month, or as frequently as once per second
continuously. The MSB of each Alarm register is a
Match bit. Examples of the Match bit settings are
shown in Table 4. Alarm Match Bit Examples.
Selecting none of the match bits (all „1‟s) indicates
that no match is required. The alarm occurs every
The alarm operates under VDD or VBAK power. If the
system controller is being used to detect an alarm
while the FM3130 is powered on VBAK only, the ACS
pin may cause extra IBAK current when the alarm is
activated. To avoid battery drain, the ACS pin can be
Rev. 3.2
Sept. 2011
Page 6 of 22
RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
