AK09915 Datasheet, PDF (32/42 Pages) Asahi Kasei Microsystems – 3-axis Electronic Compass

[AK09915]
Measurement data is stored in two’s complement and Little Endian format. Measurement range of each axis is
-32752 to 32752 in 16-bit output.
Table 11.3 Measurement magnetic data format
Measurement data (each axis) [15:0] bits
Two’s complement
Hex
Decimal
0111 1111 1111 0000
7FF0
32752
|
|
|
0000 0000 0000 0001
0001
1
0000 0000 0000 0000
0000
0
1111 1111 1111 1111
FFFF
-1
|
|
|
1000 0000 0001 0000
8010
-32752
Magnetic flux
density [µＴ]
4912(max.)
|
0.15
0
-0.15
|
-4912(min.)
When FIFO is enabled (FIFO bit = “1”);
By accessing HXL register, the oldest data set is passed to the read register from the buffer. Reading ST2
register is regarded as the finish of reading out one set of data. Then the read data set is deleted and the next
oldest data set will be ready to be read. If ST2 register or HXL register is not read, the same set of data is
kept in the read register. When reading out data, always start with HXL register and finish with ST2
register.
11.3.6.TMPS: Dummy
Addr.
Register
name
D7
D6
D5
D4
D3
D2
D1
D0
Read-only register
17h TMPS
0
0
0
0
0
0
0
0
Reset
0
0
0
0
0
0
0
0
TMPS[7:0] bits: Dummy register
11.3.7.ST2: Status 2
Addr.
Register
name
D7
D6
D5
D4
D3
D2
D1
D0
Read-only register
18h
ST2
0
0
0
0
HOFL INV
0
0
Reset
0
0
0
0
0
0
0
0
HOFL bit: Magnetic sensor overflow
“0”: Normal
“1”: Magnetic sensor overflow occurred
In Single measurement mode, Continuous measurement modes (1 to 6) and Self-test mode, magnetic sensor
may overflow even though measurement data registers are not saturated. In this case, measurement data is
not correct and HOFL bit turns to “1”. When measurement data register (HXL to HZH) is updated, HOFL
bit is updated. Refer to 9.4.3.6 for detailed information.
015006484-E-02
- 32 -
2016/7