User Manual

MPU-9250 Register Map and Descriptions
Document Number: RM-MPU-9250A-00
Revision: 1.4
Release Date: 9/9/2013
This register disables I
2
C bus interface. I
2
C bus interface is enabled in default. To disable I
2
C bus
interface, write “00011011” to I2CDIS register. Then I
2
C bus interface is disabled.
Once I
2
C bus interface is disabled, it is impossible to write other value to I2CDIS register. To enable I2C
bus interface, reset AK8963 or input start condition 8 times continuously.
5.13 ASAX, ASAY, ASAZ: Sensitivity Adjustment values
Addr
Register name
D7
D6
D5
D4
D3
D2
D1
D0
Read-only register
10H
ASAX
COEFX7
COEFX6
COEFX5
COEFX4
COEFX3
COEFX2
COEFX1
COEFX0
11H
ASAY
COEFY7
COEFY6
COEFY5
COEFY4
COEFY3
COEFY2
COEFY1
COEFY0
12H
ASAZ
COEFZ7
COEFZ6
COEFZ5
COEFZ4
COEFZ3
COEFZ2
COEFZ1
COEFZ0
Reset
-
-
-
-
-
-
-
-
Sensitivity adjustment data for each axis is stored to fuse ROM on shipment.
ASAX[7:0]: Magnetic sensor X-axis sensitivity adjustment value
ASAY[7:0]: Magnetic sensor Y-axis sensitivity adjustment value
ASAZ[7:0]: Magnetic sensor Z-axis sensitivity adjustment value
 Sensitivity Adjustment
The sensitivity adjustment is done by the equation below;
( )






+
×−
×= 1
128
5.0128ASA
HHadj
,
where H is the measurement data read out from the measurement data register, ASA is the sensitivity
adjustment value, and Hadj is the adjusted measurement data.
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