AK8975 Datasheet, PDF (12/34 Pages) Asahi Kasei Microsystems – 3-axis Electronic Compass

6.3. Operation Modes

AK8975/C has following four operation modes:
(1) Power-down mode
(2) Single measurement mode
(3) Self-test mode
(4) Fuse ROM access mode
[AK8975/C]
By setting CNTL register MODE[3:0] bits, the operation set for each mode is started.
A transition from one mode to another is shown below.


















P
o
we
r-
do
wn


















_m
o
d
e







MOD E[3:0]=“0001”
























Transits automatically













Single m easurement mode
Sensor is measured for one time and data is output.
Transits to Power-down m ode automatically after
measurement ended.












MOD E[3:0]=“0000”


















































MOD E[3:0]=“1000”











Transits automatically












MOD E[3:0]=“0000”
Self-test m ode
Sensor is self-tested and the result is output. Transits
to Power-down m ode automatically.

MODE[3:0]=“1111”

MODE[3:0]=“0000”
Fuse R OM access m ode
Turn on the circuit needed to read out Fuse ROM.
Transits to Power-down mode by writing
MODE[3:0]=“0000”.


Figure 6.1 Operation modes
When power is turned ON, AK8975/C is in power-down mode. When MODE[3:0] is set, AK8975/C transits to
the specified mode and starts operation. When user wants to change operation mode, transit to power-down
mode first and then transit to other modes. After power-down mode is set, at least 100μs(Twat) is needed
before setting another mode.
MS1187-E-02
- 12 -
2010/05