H3LIS331DL Datasheet, PDF (24/38 Pages) STMicroelectronics – MEMS motion sensor: low-power high-g 3-axis digital accelerometer

Register description
7
Register description
H3LIS331DL
The device contains a set of registers which are used to control its behavior and to retrieve
acceleration data. The register address, consisting of 7 bits, is used to identify them and to
write the data through the serial interface.
7.1
WHO_AM_I (0Fh)
Table 16. WHO_AM_I register
0
0
1
1
0
0
1
0
Device identification register.
This register contains the device identifier that for the H3LIS331DL is set to 32h.
7.2
CTRL_REG1 (20h)
Table 17. CTRL_REG1 register
PM2
PM1
PM0
DR1
DR0
Zen
Yen
Xen
PM2 - PM0
DR1, DR0
Zen
Yen
Xen
Table 18. CTRL_REG1 description
Power mode selection. Default value: 000
(000: power-down; Others: refer to Table 19)
Data rate selection. Default value: 00
(00:50 Hz; Others: refer to Table 20)
Z-axis enable. Default value: 1
(0: Z-axis disabled; 1: Z-axis enabled)
Y-axis enable. Default value: 1
(0: Y-axis disabled; 1: Y-axis enabled)
X-axis enable. Default value: 1
(0: X-axis disabled; 1: X-axis enabled)
The PM bits allow the user to select between power-down and two operating active modes.
The device is in power-down mode when the PD bits are set to “000” (default value after
boot). Table 19 shows all the possible power mode configurations and respective output
data rates. Output data in the low-power mode are computed with the low-pass filter cutoff
frequency defined by the DR1, DR0 bits.
The DR bits, in normal mode operation, select the data rate at which acceleration samples
are produced. In low-power modes they define the output data resolution. Table 20 shows
all the possible configurations for the DR1 and DR0 bits.
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