Datasheet

DS1318
Bits 7 to 4: Periodic Rate Select (PRS3–PRS0). When
the oscillator is enabled (ENOSC = 1) the PF flag is set
at the rates determined by the following table:
Bits 3 to 0: Square-Wave Rate Select (SRS3–SRS0).
When the oscillator is enabled (ENOSC = 1) and run-
ning, and the square-wave pin is enabled (SQWE = 1),
the SQW pin outputs a square-wave signal determined
by the SRS bits according to the following table:
Parallel-Interface Elapsed Time Counter
12 ____________________________________________________________________
BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
PRS3 PRS2 PRS1 PRS0 SRS3 SRS2 SRS1 SRS0
Control Register B (0Bh)
PRS3 PRS2 PRS1 PRS0
PERIODIC FLAG
FREQUENCY
0 0 0 0 Periodic Flag Not Set
0 0 0 1 4096Hz
0 0 1 0 2048Hz
0 0 1 1 1024Hz
0 1 0 0 512Hz
0 1 0 1 256Hz
0 1 1 0 128Hz
0 1 1 1 8Hz
1 0 0 0 4Hz
1 0 0 1 2Hz
1 0 1 0 1Hz
10 1 1
1/64Hz
(Once per 1.067 Minutes)
11 0 0
1/4096Hz
(Once per 1.138 Hours)
11 0 1
1/65536Hz
(Once per 1.318 Days)
11 1 0
1/524288Hz
(Once per 0.8669 Weeks)
11 1 1
1/2097152Hz
(Once per 24.27 Days)
SRS3 SRS2 SRS1 SRS0
SQUARE-WAVE OUTPUT
FREQUENCY (Hz)
0 0 0 0 32,768
0 0 0 1 8192
0 0 1 0 4096
0 0 1 1 2048
0 1 0 0 1024
0 1 0 1 512
0 1 1 0 256
0 1 1 1 128
10 0 0 64
10 0 1 32
10 1 0 16
10 1 1 8
11 0 0 4
11 0 1 2
11 1 0 1
1 1 1 1 0.5
Periodic Flag Frequency When ENOSC = 1
Square-Wave Output Frequency When SQWE = 1,
ENOSC = 1