AK8973 Datasheet, PDF (11/31 Pages) Asahi Kasei Microsystems – 3-axis Electronic Compass

ASAHI KASEI
6. Functional Explanation
6.1. Operation Modes
AK8973 has following three operation modes:
(1) Power-down mode
(2) Sensor measurement mode
(3) EEPROM access mode
By setting MS1 register MODE[1:0] bits, the operation set for each mode is started.
A transition from one mode to another is shown below.
1) Power input VDD
2) Resetting with RSTN pin
(1) Power-down
mode
MODE[1:0]=00
MODE[1:0]=11
(2) Sensor measurement mode
(normal operation)
Set measurement
condition.
On measurement
completion, transitons to
the power-down mode
automatically.
MODE[1:0]=10
MODE[1:0]=11
(3) EEPROM access mode
[AK8973]
After turning on the power, perform a reset operation by applying "L" to RSTN pin. Then AK8973 is set to
power-down mode.
A transition to mode (2) or (3) can be made only from power-down mode. A transition to a mode (2) or (3)
must be made through the power-down mode. To make the mode transition, write the setting data into the
MODE[1:0] shown in the transition diagram. After power-down mode is set, at least 100μs(Twat) is needed
before setting another mode.
Be sure to write a measurement condition for sensor measurement mode during the power-down mode.
Write-only registers MS1 and read-only registers can be accessed in any of the modes above.
MS0561-E-01 <Preliminary>
- 11 -
2007/01