BAT32G1x9 user manual | Chapter 11 Real-time clock
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Rev.1.02
11.3.5
Clock Error Correction Register (SUBCUD).
This is a register that can correct the clock speed with high accuracy by changing the overflow value
(reference value: 7FFFH) from the internal counter (16 bits) to the second count register (SEC).
Set the SUBCUD registers via 16-bit memory manipulation instructions. After generating a reset signal,
the value of this register becomes "0000H".
Figure 11-13 Format of the Clock Error Correction Register (SUBCUD).
Address: 0x40044F34H
after reset:
0000H R/W
Symbol
15 14 13 12 11 10 9 8
SUBCUD
7 6 5 4 3 2 1 0
F7
F6
F5
F4
F3
F2
F1
F0
DEV
The setting of the correction timing of the clock error
0
Clock error correction is performed at seconds bits of "00", "20", "40" (every 20 seconds).
1
Correction for clock error occurs only when the second bit is "00" (every 60 seconds).
Write to the SUBCUD register is prohibited during the period shown below:
•DVE=0: Period of SEC=00H, 20H, 40H
• DVE=1: Period of SEC=00H
F12
The setting of the clock error correction value
0
{(F11,F10,F9,F8,F7,F6,F5,F4,F3,F2,F1,F0)
–1}
2
increased
1
{(/F11,/F10,/F9,/F8,/F7,/F6,/F5,/F4,/F3,/F2,/F1,/F0)+1}
2
Decrease
When (F12, F11, F10, F9, F8, F7, F6, F5, F4, F3, F2, F1, F0) =
(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1),
(1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,,0,0,0,0,0,,0,,0, Clock error correction is not performed
at 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
The range of correction values: (F12=0)
2,
4,
6,
8,
...
, 8186, 8188
(F12=1)
–2, –4, –6, –8, ……
,
–8186, –8188
Note: "/"
indicates the value after each person is reversed.
The ranges that can be corrected by the Clock Error Correction Register (SUBCUD) are as follows.
DEV = 0 (correction every 20 seconds)
DEV = 1 (correction every 60 seconds).
Correctable range
-12496.9ppm
~
12496.9ppm
-4165.6ppmto4165.6ppm
Maximum quantization
error
±1.53ppm
±0.51ppm
Minimum resolution
±3.05ppm
±1.02ppm
Note When the correction range is outside the range of
–4165.6ppm
to
4165.6ppm, the
DEV
position
must be
"0".
THEV
0
0
F12
F11
F10
F9
F8