AK8998 Datasheet, PDF (56/59 Pages) Asahi Kasei Microsystems – Preliminary

[AK8998/W/D]
b) OSC variable ratio storing register (Register name: CM2)
It is used for adjustment of the oscillator frequency of AK8998. The counted value in the
internal counter is stored. Since the internal counter is overflowing when a count value shows
FF hex, measure again by re-defining High level period.
This register is readonly. In addition, the value of the register returns to the initial value on the
following conditions.
■ At the power up
■ When CM1 register is written
■ When CSCLK=Low is maintained 0.5msec or more
■ When ETST[0] is set to "L"
Address : 01 hex D[7:0]=CT[7:0]
(This is not a nonvolatile EEPROM, but a volatile register.)
CT[7:0]
Count value
Ratio
Comments
Dec Hex
Bin
0 00 00000000
1 01 00000001
(time)
0
1
（%）
0
Default
-99
：：
：
：
98 62 01100010
98
99 63 01100011
99
100 64 01100100
100
101 65 01100101
101
102 66 01100110
102
：
-2
-1
0
Ideal value
1
2
：：
：
：
254 FE 11111110
254
255 FF 11111111
-
：
154
-
Counter error
c) S/H circuit output error adjustment register (Register name: SH1 to SH4)
It is used for adjustment of the S/H circuit output error of AK8998.
The value of the register returns to the initial value on the following conditions.
■ At the power up
■ When CSCLK=Low is maintained 0.5msec or more
It is necessary to set up a register in order of the following.
(This is not a nonvolatile EEPROM, but a volatile register.)
No. Register Name Address Data
Comments
1
SH1
19hex
0Ahex
2
SH2
10hex
34hex
3
SH3
12hex
40hex
4
SH4
17hex
08hex
Note) Other Data is prohibited for setup.
MSxxxxx-E-00
- 53 -
2011/12