LIS331HH Datasheet, PDF (28/37 Pages) STMicroelectronics – MEMS digital output motion sensor ultra low-power high full-scale 3-axes “nano” accelerometer

Register description
LIS331HH
BDU bit is used to inhibit output registers update between the reading of upper and lower
register parts. In default mode (BDU = ‘0’) the lower and upper register parts are updated
continuously. If it is not sure to read faster than output data rate, it is recommended to set
BDU bit to ‘1’. In this way, after the reading of the lower (upper) register part, the content of
that output registers is not updated until the upper (lower) part is read too.
This feature avoids reading LSB and MSB related to different samples.
7.5
CTRL_REG5 (24h)
Table 29. CTRL_REG5 register
0
0
0
0
0
0
TurnOn1 TurnOn0
Table 30.
TurnOn1,
TurnOn0
CTRL_REG5 description
Turn-on mode selection for sleep to wake function. Default value: 00.
TurnOn bits are used for turning on the sleep to wake function.
Table 31. Sleep to wake configuration
TurnOn1
TurnOn0
Sleep to wake status
0
0
Sleep to wake function is disabled
1
1
Turned on: The device is in low power mode (ODR is defined in
CTRL_REG1)
Setting TurnOn[1:0] bits to 11 the “sleep to wake” function is enabled. When an interrupt
event occurs the device is turned to normal mode increasing the ODR to the value defined in
CTRL_REG1. Although the device is in normal mode, CTRL_REG1 content is not
automatically changed to “normal mode” configuration.
7.6
HP_FILTER_RESET (25h)
Dummy register. Reading at this address zeroes instantaneously the content of the internal
high pass-filter. If the high pass filter is enabled all three axes are instantaneously set to 0g.
This allows to overcome the settling time of the high pass filter.
7.7
REFERENCE (26h)
Table 32. REFERENCE register
Ref7
Ref6
Ref5
Ref4
Ref3
Ref2
Ref1
Ref0
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Doc ID 16366 Rev 1