Datasheet

[AK09918]
016014242-E-00 2016/11
- 24 -
ST2: Status 2
11.3.6.
Addr.
Register
name
D7
D6
D5
D4
D3
D2
D1
D0
Read-only register
18h
ST2
0
RSV31
RSV30
RSV29
HOFL
RSV28
0
0
Reset
0
0
0
0
0
1
0
0
ST2[6:4] bits: Reserved register for AKM.
HOFL: Magnetic sensor overflow
“0”: Normal
“1”: Magnetic sensor overflow occurred
In Single measurement mode, Continuous measurement mode 1, 2, 3, 4, and Self-test mode, magnetic sensor
may overflow even though measurement data register is not saturated. In this case, measurement data is not
correct and HOFL bit turns to “1”. When measurement data register is updated, HOFL bit is updated. Refer
to 9.4.3.6 for detailed information.
ST2 register has a role as data reading end register, also. When any of measurement data register (HXL to
TMPS) is read in Continuous measurement mode 1, 2, 3, 4, it means data reading start and taken as data
reading until ST2 register is read. Therefore, when any of measurement data is read, be sure to read ST2
register at the end.
CNTL1: Dummy 11.3.7.
Addr.
Register
name
D7
D6
D5
D4
D3
D2
D1
D0
Read/Write register
30h
CNTL1
0
0
0
0
0
0
0
0
Reset
0
0
0
0
0
0
0
0
CNTL1[7:0] bits: Dummy register.
CNTL2: Control 2 11.3.8.
Addr.
Register
name
D7
D6
D5
D4
D3
D2
D1
D0
Read/Write register
31h
CNTL2
0
0
0
MODE4
MODE3
MODE2
MODE1
MODE0
Reset
0
0
0
0
0
0
0
0
MODE[4:0] bits: Operation mode setting
“00000”: Power-down mode
“00001”: Single measurement mode
“00010”: Continuous measurement mode 1
“00100”: Continuous measurement mode 2
“00110”: Continuous measurement mode 3
“01000”: Continuous measurement mode 4
“10000”: Self-test mode
Other code settings are prohibited
.
When each mode is set, AK09918 transits to the set mode. Refer to 9.3 for detailed information.